92 Stealth-MAF sensor-Problem Area?

[2old]

Originally Posted by hink12341234

I will try to describe the miss. The car will start just fine but you can feel the miss right after that. At idle the miss is not that noticeable but it's there. Where you really feel the miss is when your in 1st gear you give it some gas to accelerate and shift to 2nd gear and you can really feel the miss at this point. It feels like the engine can't handle the opened up throttle(gas)and it sputters. The noise coming from the exhaust is not normal at this point. It sounds like the engine is flooded in some way. The one constant problem with this miss is when you are going 30mph and you try to maintain that speed(not any faster than that)the car will buck back and forth. This is one symptom that has never changed. The miss is very noticable at this point. If you accelerate slowly through the gears it's not as noticable. Like I said before the exhaust tone has a funny sound to it. This problem has not tripped the CEL light. I'm going out right now and checking for codes with my multi meter. Will let you know what I come up with.

As I said, check the exhaust... It really sounds like a plugged cat (fine at idle, more prominant with more gas)... But it still can potentially be an exhaust leak.

[hink12341234]

Just checked for fault codes. Nothing came up. CEL does come on for a brief second so it's not burned out. Tailpipe color is black not blue. Have not checked the timing. I have always wondered about the timing. The one tool I don't have is the inductive timing light. That is the one thing I was going to have done at the shop. I hear you when it comes to haveing work done at the dealer or shop.
I'm lucky because I have a mechanic that has done work for me for the last 28 years.Trouble is we moved and he's 2 hrs from here. I was a rural mailcarrier for 28 years so I have done my share of work on cars. Since 1992 I have driven Dodge Spirits on the route(before that it was 4WD Subarus)and it was one very good car. My Spirits had the 3.0L engine with the tried and true Mopar 3-speed auto trans. All total I put on over 300,000 miles on my Spirits. These cars were very easy to fix. All you needed to do was the key on/off/on/off to find a fault code. In all I replaced 5 O2 sensors over the years. 4 times it did not set the CEL light but the code for a faulty 02 sensor came up checking how many times you counted the CEL flashing on and off. Dealer told me sometimes a faulty 02 sensor would not trip the CEL light.Before I forget I have put new plugs,new wires and a new 02 sensor on. These were the original's so I put new ones on.Also sent the fuel injectors in and had them rebuilt and checked. So with no CEL codes which direction should I go? Thanks for your help.

[3kvr4]

Originally Posted by hink12341234

Tailpipe color is black .

If the color is black, then you are passing 2 much gas. Check injectors. My vr4 is going trew the same problem. but know i changed them along with MAF, TPS, cam sensor

[Linebckr49]

our cars run rich from the factory settings on the ECU. its just a safety measure, so you'll get quite a black exhaust. its normal.

as for the timing, i don't think a timing light (basically a strobe light) will help you . i've never heard of ppl using those old school tools on our mitsus. to check the timing, all you have to do is jack the car up on the front driver side, remove driver side front tire, remove plastic pieces around crank pulley, rotate crank pulley until timing mark on crank pulley is aligned with mark on crank AND timing marks on cam sprockets are aligned with marks on valve covers.

if you want pics, let me know and i'll find some for you.

[hink12341234]

Hey if you can find some pictures I would appreciate it. Don't know exactly what you are talking about but i'm willing to try and possibly learn something.

[Linebckr49]

i'll find some pictures and diagrams for checking the timing.

in the meanwhile, i would take the advice of 2old and check the exhaust for a plugged pipe or a leak.

[Igovert500]

You could try the 60k tuneup links in teh FAQ. They will have timing pics.

[Linebckr49]

thanks, Igovert.

jack up the car, drivers side front tire. remove tire. remove plastic. you will see this pic below. from left to right: A/C pulley, a/c belt idler pulley, crank pulley. NOTE: in this pic the a/c accessory belt has been removed. you don't need to remove it.



on top of engine, drivers side, remove timing belt covers to reveal timing belt running around camshaft sprockets.



put a 1/2" drive ratchet (and perhaps a small extension socket) in the crank pulley. rotate crank pulley clockwise until timing marks on the camshaft sprockets align with timing marks on valve cover.



here's another pic. this is the front bank of camshafts. the timing marks on the camshaft sprocket (a dimple), and the timing marks on the valve cover (a triangle) have been colored pink for viewing purposes.



and here is a pic of the rear bank of camshafts. the marks in the valve cover are a bit harder to see, but if you look carefully you can see them.



So now that you have turned the crank pulley, make sure ALL the timing marks line up perfectly. even if one cam sprocket is off by one tooth, it is considered out of time.

just a few days ago, i and another 3S guy were helping a friend with his timing. for some weird reason, his car wouldn't start, we suspected timing after other possibilities checked out ok. we discovered his timing was off by 2 teeth on exhaust cam-front bank, and off by 1 tooth intake cam-rear bank, and 4 teeth exhaust cam-rear bank. we reset the timing, and car started right up.

BUT since your car is running, however poorly, timing may be off by 1 or 2 teeth, and it could still run. the timing would most likely be retarded, that's why it would run poorly.

[hink12341234]

So if my timing is off how do I make the adjustment to properly time the engine? Thanks for the pictures,it helps a geat deal. John

[hink12341234]

I checked the Stealth 316 site and it shows you how to time the engine. It looks like the timing adjustment is the same as it was many years ago. Years ago all we did was mark the timing mark,point the timing(strobe) light and turn the distibutor until the marks were matched. I'm just lost when it comes to lining up the timing belt with the sprockets. Thanks again for your help. John

[Linebckr49]

Originally Posted by hink12341234

I checked the Stealth 316 site and it shows you how to time the engine. It looks like the timing adjustment is the same as it was many years ago. Years ago all we did was mark the timing mark,point the timing(strobe) light and turn the distibutor until the marks were matched. I'm just lost when it comes to lining up the timing belt with the sprockets. Thanks again for your help. John

could you provide me with a link? i can't find where stealth316 shows how to 'time the engine.'

[Linebckr49]

ok, after more searching stealth316 (its a huge site, more reading than any 3S expert could ever do. more links than i want to know about. basically a very impressive bastion of 3S knowledge) i found the timing page i think you are talking about: http://stealth316.com/2-ignition-timing.htm

<thinking out loud> i read, re-read, and did some thinking. a problem similar to this came up when me and a friend were working on another guy's 92 3000GT last week. but before i get to that, let me address the link above. that page on stealth316 provides one of the methods to check the timing on 91 & 92 stealths/3000GTs. b/c of the location of the CAS, the timing on the 91 & 92 cars could also be ADJUSTED.

ok, so if the link provides a way to check timing on the 91 & 92 cars, then how would you check the timing on 93+ cars? we use the method i described above by aligning timing marks on the crankshaft and the camshafts. this method will ALSO work on 91 & 92 cars, however it is simply a tad more difficult, as me and a friend discovered when working on this guys 92 3000GT.

the problem we came across is that on 91 & 92 cars, there is not a noticeable timing mark on the crankshaft (at least we had a hard time identifying the mark). our dilemma is documented here http://www.3si.org/forum/showthread....7&page=1&pp=10 .

to summarize what is discussed in the aforementioned thread, there is a dimple on the crankshaft which is the timing mark on 93+ cars. for 91 & 92 cars, the timing mark correlates to the sheer pin. so once we knew how to identify the timing mark on his 92 car, we aligned all the marks, started the car, and she purrred nicely.

----------------------------

in conclusion, there are 2 ways to check timing on 91 & 92 cars. ONE is the method using the timing light. TWO is to simply align the timing marks on the crankshaft and the camshaft sprockets.

you can choose which one to do. honestly (and i'm biased), the latter method is seems easier because it doesn't require the use of a timing light (granted, i'm not very familiar with them so i see it as easier). also, all you need is basic tools, and a sharp eye. to aid in this process, once you identify the timing marks, i would recommend you mark them all with a paint pen or something to make them stand out.

hope this helps.

[hink12341234]

It makes sense to me to do it your way. Isn't this the only method that anyone use to see if in fact the timing belt jumped a tooth? If it jumped a tooth or two how can you time it by using a strobe timing light? It would seem to me that your way of timing it would make sure the valves are opening and closing as they should to make the engine run right.
This timing issue is a little confusing. If it has jumped a tooth how would you adjust it? I would assume that basically what you are doing is installing a timing belt and to do it right you would first make sure that everything is lined up before you put the belt back on. I don't see how adjusting the CAS would help with the timing of the engine if the timing belt is installed without first making sure the timing mark on the sprocket is lined up with the other one.
This is why the method that you have shown in your pictures has got to be done or else the valves are opening and closing at the wrong time and this would make the engine not run right or not even run.
I hope i'm clear on this. I just think that using a strobe light and changing the belt are two different procedures. Again,Thanks for your help.

[Linebckr49]

Originally Posted by hink12341234

This timing issue is a little confusing. If it has jumped a tooth how would you adjust it? I would assume that basically what you are doing is installing a timing belt and to do it right you would first make sure that everything is lined up before you put the belt back on. I don't see how adjusting the CAS would help with the timing of the engine if the timing belt is installed without first making sure the timing mark on the sprocket is lined up with the other one.

you're exactly right. your intuition and logic is wonderful. because, for example, say we used the strobe light method and then found timing was off. well then we would have to do the alignment method to verify timing was off, then correct timing by method 2.

so to answer your question about how to correct the timing, you simply remove the belt, align the marks (camshaft sprockets, crankshaft), and re-install belt.

however simple it may sound, its a bit technical because we have a hydraulic automatic timing tensioner. this part is the crux of our engine. so we loosen the tensioner PULLEY, which will loosen tension on the belt. belt can be removed, timing marks aligned, belt re-installed, and then the hard part is re-installing the timing tensioner.

a picture can help me explain this better. on the right side of the timing tensioner i've circled a hole in green. the plunger on the timing tensioner must be compressed in a vice (i've used a c-clamp to apply slight pressure before, but i wouldn't do it again, nor would i recommend it). once the plunger is compressed far enough, a metal (tough, sturdy metal) pin, aka the grenade pin, can be inserted through the circled hole, which goes through the plunger, and out through the hole on the opposite side of the tensioner. this pin will secure the tensioner so it can be re-installed.



HERE IS THE ORIGINAL PIC, FOR SAKE OF CLARITY.



when re-installing the timing tensioner, you must put the right amount of force on the tensioner pulley, which in-turn exerts force on the timing tensioner. you know you've put the RIGHT amount of force on the timing tensioner (via tensioner pulley) when you can spin/twist the pin freely inside the hole in the timing tensioner. you should also be able to move it in/out freely (but don't remove it entirely, just move it back and forth). now you've set the proper torque on the tensioner pulley, tighten the bolt on the pulley so it will stay in place. then test to see if the pin moves freely. if yes, you've done it right and can remove the pin! if no, then loosen the pulley bolt, reset the force on the tensioner via the pulley.

this picture can help explain. it was taken from the user manual.

[hink12341234]

Again,Thanks for the info and pictures! My first step today is to get the wheel off and check the belt and sprockets and stuff. Like I said I want to learn something here. John