95 monte idle problem any suggestions

When I start my 95 monte carlo (3.4) it revs high to about 4 or 5 and then drops. it continues to do this until it gets warm even cutting out if i dont hit the gas. just changed the dile air control motor and it's not that. Could it be the spark plug wires are old or something to do with fuel injection. Need help if anyone had similiar problems

When I start my 95 monte carlo (3.4) it revs high to about 4 or 5 and then drops. it continues to do this until it gets warm even cutting out if i dont hit the gas. just changed the dile air control motor and it's not that. Could it be the spark plug wires are old or something to do with fuel injection. Need help if anyone had similiar problems

I have A 95 3.4 DOHC doing the same thing. From what I've learn, Its either the Intake or Head Gasket. I tryed changing the all the sensors you can think of, and the idle still has a mind of its own. It doesnt stall, and will start fine. But after it is placed in gear, the RPM jump anywhere to 3000. It is driveable but you are off to the races. At times it will run normal, but it I shift (automatic) into park it RMP's race off again. I had it into a dealer and he said its a vaccum leak. On top of this, it leaks oil from somewhere around the rear head.
At this time I have the intake off and I am hoping that by replacing the upper and lower gasket , this will solve both problems. I have found anti-freezze in the top of the rear head. But there is no water on the dip stick. There is however water in the plugs.
Being DOHC I really dont want to pull the heads. I looked though this site and found several idle issue that end up being the intake gasket. I also dont have the tools needed for that job.
I dont know if this info helps you. But your not alone in this.

If anyone has any other info. or a similiar issue please reply.:screwy:

I think you're right on track.:thumbsup:

I am having the same problems. I also own a 1995 monte carlo z34 (3.4) DOHC. Tomorrow I am taking out the PROM chip (in the computer) and brining it into a dealer to see if there is an updated chip. I have a very close frend whos a mechanic (I trust him with everything) who reccommended looking into this. The GM dealer should be able to see if there is an updated chip and he said it should run anywhere from $75 to $125. Ive done some reserch and found that this cold start issue has been common across certian GM models, and an updated PROM has fixed the issue. I guess I will see?

When the car is started up, it does not run off sensors, it runs of the "stats" inside that PROM chip. When the engine gets up to operating temp, it will run off the sensors readouts.

I have already replaced the intake gasket, fuel regulator, one injector, camshaft sensor and an O2 sensor.

Don't get me wrong. I am a GM fan down to my bones, I have a bowtie tattoo on my arm wrapped in barbed wire, but this series of engine is NO GOOD!

I will post what I find out!

update: I went down to the local dealer and ordered an updated PROM chip, $100 shipped, will have it soon. There was a bulliten posted for the car, and one of the updates was a cold start issue.... please fix my car.......I will post the results!

Installed the updated PROM. Didn't change a thing, actually my car dies in the morning now.......

WHAT THE HELL IS THE FIX?!?!

Was there a relearn procedure to perform after the PROM was installed?

not that i know of, its the old style chip, that looks like a piece of RAM in a computer, i just swapped the pieces (of course disconnecting the negative terminal on the battery before doing anything!) The relearn process should be instantaneous right? On startup, the car uses that PROM chip to determine how much air, fuel and yadda yadda yadda to give the car, after it warms up it runs off the sensors.

My car idles terribly, 800rpms to 3k rpms and sputters and when i go to drive it, it feels like theres no power, sometimes i can hardly brake. After it warms up the car runs fine.

Ive been fighting this problem for 3 months now.

I'd double check with the dealer of puchase on that.

As you elduded, you know what's going on at startup.

However, I normally, any time after power has distrupted for a period of time to the ECM drive the vehicle under all 'normal' operating conditions as the running history has in most cases been lost. This would included stop and go, cruising, some highway (or as close to) speeds.

At startup tho, a few sensors are used for the cold start mixture, the intake air, engine coolant temp and MAF.

Funny thing. Today it started just fine and ran like a charm.... tomorrow is another day of test.

Is there a relearn process? I was almost sure it was just an instentaneous thing? Ive read alot about this problem, but have found no answers. I replaced the fuel regulator, head gaskets, one injector, a vaccum line, cam sensor, O2 sensor, and a side marker socket and ive only owned the car about half a year maybe....

the fuel filter got clogged and caused a injector to go bad ( i think) and the fuel regulator to go bad. So that was party my fault for not checking that.

I'm only 21, but i feel i know enoguh about cars to do alot myself. Ive replaced the tranny and engine in my 89 silverado, gosh i love working on the simple stuff, i can literally sit in the engine compartment on that beast! (350cu)

if you have any other ideas let me know!

It started up awesome today!

We'll see if it actually needed a relearn process, i'll keep this post up to date.

Maybe i finnaly found the problem????

I've talked to alot of car people/mechanics and done as much reserach as I can find on this topic. I've read alot about cold start issues with this motor (3.4) Sometimes its the intake gasket leaking, sometimes it needs a PROM update. Ive already done the head gasket replacement, that didn't work. Then I did the PROM chip update, its very simple, just make sure you disconnect the batter before even touching the computer :)

I hope my good luck keeps running!!

An intake leak can be determined by spraying starting fluid or WD-40 along the seam of intake/heads. This PROM update issue is interesting. Keep us informed if it continues to run correctly.

[I hope my good luck keeps running!![/quote]

I have the same car, same exact problem. Before I found this forum, I replace the mass air flow sensor, the idle air control valve, plugs, and soaked (what I could reach of) the intake manifold with starting fluid - but nothing made a difference. I finally parked the car now that Winter is here - it's completely helpless in the cold. It won't run right until it reaches @ 160F, by then I'm already there...:banghead: I was skeptical of the PROM chip change working, but now I'm getting hopeful - Keep posting ChevroletTough!! Thanks

There are good days and there are bad days.... Im completely confused. Some days it runs fine on startup and some days it doesn't. Im going to look into it further. Its almost like my car has a short somewhere, somedays it runs fine and other not... Today is a new day.

Man, I know you guys are saying you replaced the upper and LOWER intake manifold gaskets but I think there may still be an issue there to be resolved. That lower one can be a little bit of a pain to get it right. Needs to be aligned right along with torqued right. A couple of the outside bolts are a little tough to get the right angle with your torque wrench. I have also noticed a difference in gasket quality. I think the last set I put on were felpro and have been the longest lasting so far. Another thing was one time a parts store guy told me that there was a quality update issued at one time for that lower gasket. Duno if that was true or not. This idle issue is well known for these engines and almost always is related to a vac leak. I will try to watch this thread as I belong to a couple other forums on this engine. Oh another "fix" ive read about(but am going to do in the nxt 2 weeks) is the GM Top Engine Cleaner.

well ive just had more problems... my window got stuck down, my tail lights don't work (found the problem) and the O2 sensor is bad AGAIN. The car has NO power becasue of a bad O2 sensor, so im going to be working on this car the rest of my life i swear... Im going to get it working and sell it, and get my dream car, a 2001 Pontiac Grand Prix GTP (supercharged.)

i'll keep you up to post in the next week or so... good luck to alll of you who have this car.... and the 3.4 engine...

So what did you find out? Did the EPROM chip take care of it? My sons 95 Monte has problems soundin like yours.

So what did you find out? Did the EPROM chip take care of it? My sons 95 Monte has problems soundin like yours.

well i ended up having to replace the O2 sensor again (check engine light, used a code reader.) Some days i have good luck and others i dont, im almost positive i have narrowed down the problem, the harness that runs from the O2 sensor itself to the computer, the wires are bad, need to splice into them and run new ones. (you cannot buy the harness, its part of the computer harness... $1200.00.....) But as of last week, the tranny died, so i give up. Im not sticking any money into this car anymore. If you have the 3.4L engine, i would suggest selling it. This is the worst engine/tranny combo GM has ever built. This car didn't even last 6 months. Ive put $500 into is since ive had it too. Im switching some of the newer parts to my sister's car and then scrapping it probably.

Good luck to you all...

i have the same exact problem, start my car it idle up to around 4 to 5 rpm and and then just shuts off. Ill start it again and i would have to give it gas for about 3 minutes and it will act normal. what should i do to get it fixed?:confused:

i have the same exact problem, start my car it idle up to around 4 to 5 rpm and and then just shuts off. Ill start it again and i would have to give it gas for about 3 minutes and it will act normal. what should i do to get it fixed?:confused:

truthfully ive spent so many hours working to fix this problem. I still don't know the answer, is your service light on? The problem that started this was that my fuel filter was basically plugged.... So id check that. If you have access to a computer tester, check the codes.

Ive replaced:
an injector
02 sensor
Camshaft Sensor
Head Gasket
Fuel Regulator
Updated PROM Chip

No Luck... Sometimes it would start up fine. I think i may have narrowed down the problem. Its the wire harness that runs from the 02 Sensor... its shorting out, but i could still be wrong..

Good luck man. Damn the 3.4L DOHC

Another issue that is again very common with the 3.4(x) is that the the metal casing that houses the PCM for these cars has a big problem with rotting(rusting). Once this happens and water starts getting in, it can cause all kinds of problems from poor performance, a problematic misfire that goes away and come back, and generally poor performance. EGR malfunctions, and idle problems/stalling are other issues that it can cause.

If you are getting symptoms that you just cannot pinpoint, take off/out your PCM, take it right apart/open it up and see if its got dirt/rust/sand/salt inside . If it does it needs to be cleaned, the electronics/circuits on the board itself have to be carefully checked. Usually the quad driver circuits get affected and you have to get it fixed or replaced.

I myself have a '95 monte with the 3.4 and I did have mysterious problems that I just couldn't find. A friend(fellow tech at the time) told me about this,and I did what he said, and sure enough that was it. The car would stall, misfire when it was raining, or damp outside, and was generally sluggish. I had to clean the PCM right up, solder one of the circuits that broke apart and seal the metal box with silcone - havn't had a problem since.

Another thing also I'd thought I'd mention too. Many people who have these cars with the 3.4 eventually find out that the mysterious oil leak they thought was a oil pan gasket, or main seal, is in fact the distributor halfshaft. Many soon after that find out that the only way to replace this $1.50 rubber o-ring, is to pull the rear head. An easier way to fix this problem, is to carefully unbolt the hold down bolt, pull it off, take the distributor hold down clamp off, and slowly pull up the shaft and get it out as far as possible. Put some good gasket maker on the new rubber seal, and carfully slide it over the shaft. This takes time and it tedious, as you have little space to do this. Use a screwdriver, and get the rubber o-ring on. Your not going to get it where its suppose to be. To do that you have to take the shaft out, and you can't do that because as I mentioned befroe, for this engine the rear head has to come off. After you get the gasket over the shaft, put the hold down clamp, and bolt it down. Make sure the bolt for the clamp is tight, and pulls the shaft down, to approx. where it was before. This will give you a seal, and solve that leak without taking the head off and doing it that way. I have done this on a few cars, includng my car, and I have never had a problem.

thanks for the info, that sounds like it might be a fix!

uhhhh whats a PCM? I know where the EGR valve is...

now i need to fix the tranny..

PCM - Powertrain Control Module, or the earlier version of this is ECM Engine Control Module. Its the cars computer brain box,, as others ahve called it too. For this car, it located on the passenger side front fender, under the hood of course.

ok yeah. Basically the computer. I replaced that a month ago, with the updated prom chip. No difference. The seal was in great condition. I even herad air pressure release when i took the cover off.

I am also the proud owner of a 95 monte Z34 and this car has me at my wits end. I am only a few years old where I live and have found it hard to trust what I am being told in regards to my cars issues.
I have replaced the EGR valve and other small things, have been told I am only running on 4 cylinders, two are not firing..go figure. Then one day my car wont stay running and when I give it gas it acts like it is stuck...hesitating a lot! I take it to a new mechanic who says he cleaned the Mass Air Flow Sensor and with that said my car was purring again, wonderful...and it only cost me 60.00 but after two weeks the same exact issue has reappeared. One day it was running great and the next thing I knew I was stuck at the store because it refused to start...dang thing! Needless to say my car has been parked for a month now and I am debating my next move. Who to trust, and everything I read on here sounds just like my car...but noone has mentioned some of the things mentioned here. I was told to replace the air flow sensor...and since he did clean it and it was running smooth for some time afterwards, that would be a smart move, right? I love my car and dont want to get rid of her if at all possible! Plus she is parked with a full tank of gas and brand new tires to boot! lol

I am also the proud owner of a 95 monte Z34 and this car has me at my wits end. I am only a few years old where I live and have found it hard to trust what I am being told in regards to my cars issues.
I have replaced the EGR valve and other small things, have been told I am only running on 4 cylinders, two are not firing..go figure. Then one day my car wont stay running and when I give it gas it acts like it is stuck...hesitating a lot! I take it to a new mechanic who says he cleaned the Mass Air Flow Sensor and with that said my car was purring again, wonderful...and it only cost me 60.00 but after two weeks the same exact issue has reappeared. One day it was running great and the next thing I knew I was stuck at the store because it refused to start...dang thing! Needless to say my car has been parked for a month now and I am debating my next move. Who to trust, and everything I read on here sounds just like my car...but noone has mentioned some of the things mentioned here. I was told to replace the air flow sensor...and since he did clean it and it was running smooth for some time afterwards, that would be a smart move, right? I love my car and dont want to get rid of her if at all possible! Plus she is parked with a full tank of gas and brand new tires to boot! lol

cleaning a MAF (mass airflow sensor) ?!?!?! what the hell??? thats a load of crap! If you have a wire tester you can test the leads from the MAF sensor. Or if its really bad, the computer should pick it up and your check engine light should come on. Sorry to hear you spent 60.00 on a crappy mechanic-gimic. This engine is a b*tch to troubleshoot especially with this problem. ive read so much about this car, i know it inside and out, and i still can't solve the damn problem. i have a very close friend whos a mechanic, so i get to use his computer diagnostics all the time and i have yet to discover the problem.... good luck man....

cleaning a MAF (mass airflow sensor) ?!?!?! what the hell??? thats a load of crap! If you have a wire tester you can test the leads from the MAF sensor. Or if its really bad, the computer should pick it up and your check engine light should come on. Sorry to hear you spent 60.00 on a crappy mechanic-gimic. This engine is a b*tch to troubleshoot especially with this problem. ive read so much about this car, i know it inside and out, and i still can't solve the damn problem. i have a very close friend whos a mechanic, so i get to use his computer diagnostics all the time and i have yet to discover the problem.... good luck man....



I didnt think the MAF could be cleaned from what I was told, I guess the guy just bought me a little more time, lol. What can I say, being a lady I always get ripped off!
In regards to the check engine light, it always comes on if I am sitting idle too long and when it comes on the car will start to studder...so I will put it in park and rev the motor a few times...then the light goes off. That has been the only issue I have had with this car, I guess I should be glad for that. I took the MAF off just a few minutes ago and brought it into the house to look at it and I dont think it is suppose to have holes in it..right? It looks like someone shoved a screwdriver right through it in two places. I am thinking of going and getting a new one and hoping that is the issue so I can get back on the road! :lol: Personally I think my car likes the attention....if it is not one thing with her it is another! Thank you for letting me know I was feed some bull...I know better then to go back to him! (although he said the computer said something about the MAF needing replaced...humm)
Again, thanks for the response!

Since you say you know much about this car, do you know much about the stereo buttons on the sterring wheel? Someone broke into the car a year ago and for some reason tried to take the volume control button from the wheel only to leave it still connected and hanging. I pushed it all back in and popped it back into place but now when I turn my wheel the volume goes down on it's own....any ideas how to solve that? None of the wires were broken so I thought I could just push it back in.

I didnt think the MAF could be cleaned from what I was told, I guess the guy just bought me a little more time, lol. What can I say, being a lady I always get ripped off!
In regards to the check engine light, it always comes on if I am sitting idle too long and when it comes on the car will start to studder...so I will put it in park and rev the motor a few times...then the light goes off. That has been the only issue I have had with this car, I guess I should be glad for that. I took the MAF off just a few minutes ago and brought it into the house to look at it and I dont think it is suppose to have holes in it..right? It looks like someone shoved a screwdriver right through it in two places. I am thinking of going and getting a new one and hoping that is the issue so I can get back on the road! :lol: Personally I think my car likes the attention....if it is not one thing with her it is another! Thank you for letting me know I was feed some bull...I know better then to go back to him! (although he said the computer said something about the MAF needing replaced...humm)
Again, thanks for the response!

Since you say you know much about this car, do you know much about the stereo buttons on the sterring wheel? Someone broke into the car a year ago and for some reason tried to take the volume control button from the wheel only to leave it still connected and hanging. I pushed it all back in and popped it back into place but now when I turn my wheel the volume goes down on it's own....any ideas how to solve that? None of the wires were broken so I thought I could just push it back in.

thats very unfotnate, im sorry to hear. The maf is a sensor that hooks up to two tiny wires that run through the air intake, i guess you could clean the sensor, but i don't see why one would do that?! Don't feel bad, alot of people get ripped off, i read that somone had a dealership fill their tires with nitrogen for $70!! what the hell?? haha. Anyway about the stero buttons, my car was a 95 and didn't have that option yet. Im not sure what your problem is, but im guessing when they pulled the button out they pulled the wires tight and when you turn the wheel the wire twists and something happens.... if your car has air bags, i wouldn't reccomend taking the steering wheel off by yourslef, it can get hairy... Id ask around, autozone seems to be pretty good at loaning tools and giving information. I also like my local napa store. Im sorry i cant exactly help, electronics are tough to troubleshoot!

About the reving to make the service light gone, my car kinda did that, i still haven't figured out the problem, and i dont' think i will persue it with the tranny being dead. This problem has plauged many people and the fix is impossible... ive narrowed it down to the wire harness that runs between the O2 sensor and the computer. But i gave up after the tranny died.

I hope you have better luck than i did...

If you use a K&N filter, or if you have driven in dirty/dusty roads for a long time, cleaning the MAF sometimes gives you a noticable improvement in performance. If you get a MAF code, its always a good idea to clean the MAF before replacing it. To clean it all you do is get brake cleaner and spray the very this wires down from both sides. Never touch these wires, there easy to break, also never use throttle body cleaner or carb cleaner because alot of these cleaners have oil in them to thats stays on parts to lubricate them - you don't want anything on the MAF sensor.

Now $60 to get the MAF cleaned, I'd go back and ask him what he did for $60 and want money back.

If you use a K&N filter, or if you have driven in dirty/dusty roads for a long time, cleaning the MAF sometimes gives you a noticable improvement in performance. If you get a MAF code, its always a good idea to clean the MAF before replacing it. To clean it all you do is get brake cleaner and spray the very this wires down from both sides. Never touch these wires, there easy to break, also never use throttle body cleaner or carb cleaner because alot of these cleaners have oil in them to thats stays on parts to lubricate them - you don't want anything on the MAF sensor.

Now $60 to get the MAF cleaned, I'd go back and ask him what he did for $60 and want money back.

acceptable answer. I guess cleaning the actual wires can be done, i was thinking the actual little black electronic "box" part of the sensor. i really don't see how those tiny wires could get dirty though.... they are so small!

If you use a K&N filter, or if you have driven in dirty/dusty roads for a long time, cleaning the MAF sometimes gives you a noticable improvement in performance. If you get a MAF code, its always a good idea to clean the MAF before replacing it. To clean it all you do is get brake cleaner and spray the very this wires down from both sides. Never touch these wires, there easy to break, also never use throttle body cleaner or carb cleaner because alot of these cleaners have oil in them to thats stays on parts to lubricate them - you don't want anything on the MAF sensor.

Now $60 to get the MAF cleaned, I'd go back and ask him what he did for $60 and want money back.

I am happy to report I took a chance and bought a new MAF sensor and it seems to have done the trick, car is running a lot better, not 100% but a lot better. Much to my amazement, when I removed the MAF sensor I found 3 screwdriver sized holes right in the middle of the metal mesh part...I asked when taking it to get the replacement and I was told "that was what I got for 60.00 bucks"...lol...I have to laugh. I did not take my car to some guy who walked in from the streets, I took it to a Chevron Service station that everyone recommends (well the 3 people I spoke to here anyway) so I am shocked they would be so sneaky. I will never go back there again.
Now for the funny stuff....since my car was jerking for so long, sputtering and acting up and all that...it seems something underneath is loose and rattling like crazy. It sounds like it might be my exhaust pipe right under my drivers door. I will be taking the car tomorrow to get that looked at a muffler shop...cant go wrong there, right?! :banghead: I love this car so much, I dont really want to get rid of her and I keep hoping with every new part she might one day decide to just go with the flow so I can spend my money on something else for once!
Thank you for all your advice and suggestions, I truely appreciate all the help I have been offered! This board is great for those of us who are "challenged"! :lol:

im glad to hear that it was partially fixed. Well if you wanted to fix the exhaust rattle yourself... just drive it up on ramps, look underneath and wiggle the exhaust with your hands (not when its hot... or wear gloves) might be a broke clap, those are like $3 down at napa, and all you need it a socket/ratchet or wrench to get them off/on. 2 nuts, easy as pie.

Assuming you have car ramps that is...

The choice is yours :) My sister had a rattle on her 95 monte z34 and it was an exhaust clamp, i just got a new one and put it on, problem solved :)

hope this helps.

im glad to hear that it was partially fixed. Well if you wanted to fix the exhaust rattle yourself... just drive it up on ramps, look underneath and wiggle the exhaust with your hands (not when its hot... or wear gloves) might be a broke clap, those are like $3 down at napa, and all you need it a socket/ratchet or wrench to get them off/on. 2 nuts, easy as pie.

Assuming you have car ramps that is...

The choice is yours :) My sister had a rattle on her 95 monte z34 and it was an exhaust clamp, i just got a new one and put it on, problem solved :)

hope this helps.


Well it seems the MAF was just PART of the problem..lol. The car is doing better but it seems I have a coil out therefore my car is now a 4 cylinder, not a V6, and it has been dumping raw fuel into the exhaust and killed the (I know I am going to butcher this spelling....but here it goes) Catallac converter. The "specialist" says that is what is causing the noise, while the car was in the air he hit the big box thingy and it rattled...he said 160.00 for a new one (installed). I have been told by someone else that I can not even buy a converter thingy for 160.00, new that is. I bought the coil pack and have located where it goes but I dont think that is something I can attempt on my own due to short arms and short temper. :rolleyes: Firestone has said they can do my coil pack for...get this....600.00! They are claiming the motor has to be pulled to do it. But it seems once I do these two things my car will purrrrrrr....or so they say.

I have taken excellent care of my car, not even a scratch (but two door dings compliments of walmart parking lot) and I am beginning to wonder if I should just sell this car to the junk yard and cut my losses. :banghead:

If you take it to the junker, I'd love to come and pick it up for ya, heck I'd give ya double what they would....if I was closer though. Installed cat for $160, thats not bad, its about right. As for the coil, its easier to get it from the bottom, drive it up on ramps(or even better hoist) and you got an easy access to it. Disconnect the negative battery cable unplug the spark plug wires, unplug the ignition module connectors, and unscrew the whole unit from the engine block. From there, take the coil off and replace whats needed. Install is reverse.

Thank you for the instructions! I will attempt to change it this weekend, as well as the exhaust issue....then maybe that will be it! I have my fingers crossed this fixes the car so I can get back on the road without fear of breaking down again.

Your welcome. i also forgot to add, make sure you unhook the battery first. If you go unpluging the ignition module and the battery is not dissconnected, you run a risk of damaging the ignition module, so make sure the battery is disconnected.

600.00 to replace a coil pack?!?!?!?!

sweet jesus.

you do not have to take the motor out to take the coil packs off. Ive had to test the spark on them before, they are in a hard spot. You will probably have to take off 1 or 2 of the fans (i can't remember if there are 1 or 2 fans) for room, but maybe not.

I am looking at a 96 monte with the 3.4. the lady told me it died when she goes around corners somtimes and dies also when she comes to a stop somtimes it dies. She says it will go down the road 100mph any other time. What do you monte pros think it could be? If it will take a boat load of money to fix, i will let her keep it. Please let me know @ lucas_wojo@yahoo.com for a faster responce on my part. I will check this board when i can also. Thanks

Ask her if it smells rich in the morning when she starts it up, like a snowmobile. Sounds like the dredded 3.4 problem that I swear is impossible to solve.....

she says it idles fast, but dosent smell gassy. Everyone has told her to change the mass air flow sensor? would that help or just rais my cost? Lucas_wojo@yahoo.com Thanks

she says it idles fast, but dosent smell gassy. Everyone has told her to change the mass air flow sensor? would that help or just rais my cost? Lucas_wojo@yahoo.com Thanks
quick way to test it. unplug the maf sensor, its the harness that plugs into a block on the air intake tubing. If the car runs crappy, then your maf sensor is fine. If you unplug it and don't notice a difference, chances are its the problem.

hope that helps

Are there any codes?Check the temp sender with a scanner.If it runs like crap when cold & then runs good when warm,could be temp sensor.I know you said you tried alot of sensors,but double check.I ran across this problem a couple times.Also check your fuel trim.Good luck.

I had all the same problems with my 95 3.4 also. it didnt start till one of the injectors went out tho. i fought and fought it and never did figure it out. had the same problem with a 3.3 in a pontiac. But any way i traded the monte for a truck just in time. i heard a clicking when turning right so i got ride of it and two weeks later the tranny went out. now a friend of mine bought it fixed the tranny and it runs great now with just a plug and wire job. the only thing anyone could find wrong was the gap on the plugs

I had the same issue with my 95 Monte, ... It sound like a intake air leak.
To find the air leak start the car and let it idle, ... spray some quick start, ... use the long plastic tube to direct it at each area that may have an air leak, around the intake manifold and at the hoses around the intake. When the engine rev's up you have found your leak. Using some hi temp rtv should correct the problem, ... all the best.