91 Camaro Starting Problems

I have a 91 Camaro RS 5.0 TBI. It will not crank with the key. We are able to turn the motor over with a screwdriver jumping off the starter...(even though it was a brand new starter, we still wanted to make sure). The battery is new also. The purple wire on the starter solenoid that goes to the neutral safety switch does not have 12 volts at either end, but I do have resistance on the two white wires (for VATS) coming off the steering column-which match the resistance for the key pellet, there is no fluctuation while switching the key from on to off several times. All fuses have been checked. There is no power at the fuel pump relay either (again...signaling VATS, but...??). The security light is not coming on (for VATS) and we tried to read the check engine light with the code key and the dash lights did not flash (we have done this before on this vehicle and it did work, it just isn't working now).

If you have any ideas on what could be going on, please help! :banghead:

...we tried to read the check engine light with the code key and the dash lights did not flash (we have done this before on this vehicle and it did work, it just isn't working now).

If you have any ideas on what could be going on, please help! :banghead:

I had a totally different problem, but the clue was that I couldn't get the trouble codes to flash.

It ended up being the ECM (not the Cal-Pack/PROM, the ECM itself). Replaced that and it's been running fine for a while now and the code flash works again (thankfully all 12s).

Does the SES light come on when you turn the key to the run/on position?

There is a starter intterupt relay behind the driver's kick panel, it could be bad..

There is a starter intterupt relay behind the driver's kick panel, it could be bad..
Is this the same as the starter enable relay? We found power going in but no power going out, but since this is linked to the VATS, we weren't sure if that meant that it was actually bad or if the VATS wasn't working correctly, if that was the reason for no power coming out of it. Any idea?

I had a totally different problem, but the clue was that I couldn't get the trouble codes to flash.

It ended up being the ECM (not the Cal-Pack/PROM, the ECM itself). Replaced that and it's been running fine for a while now and the code flash works again (thankfully all 12s).

Does the SES light come on when you turn the key to the run/on position?
No dash lights are coming on now when switching the key on except the brake light and the seat belt light.

Is this the same as the starter enable relay? We found power going in but no power going out, but since this is linked to the VATS, we weren't sure if that meant that it was actually bad or if the VATS wasn't working correctly, if that was the reason for no power coming out of it. Any idea?
Yes, same as start enable relay. YOu need to check for power going to the control side of the relay, the part that VATs energizes. Since you said the security light was not on we'd assume that VATS is doing its thing.
Now I see where you have no lights on the dash at all, Check the bulb in the SES spot, make sure it actually works. It sounds like you may have electrical gremlins in your car.

Update: We took the dash panels off and found the VATS/Passkey box. The resistance going into the box matches the resistance of the key-meaning that the wires going from the ignition to the box are intact! YAY! There is power coming out of the box from the wire going to the ECM...Is there any way to test the ECM?

Update: Still nothing. We bought a new ECM because we found out that it could be tested though certain shops, but by the time we pay a mechanic $X we could buy a new ECM (and it is 17 years old anyway, so we decided to go ahead and change it). Anyway, plugged everything back up...still nothing. The dash is still torn apart so we can't see if there are any codes flashing or not with the new computer. I guess next time we get out there we are going to keep following wires and see what happens. :banghead:

If you have any more ideas...PLEASE HELP!

There should be 4 wires going to the start enable relay. 2 are for power to the starter solenoid. The others are the control, the ECM energizes the relay. make sure when you have the key on that there is a complete circuit there (ECM controls ground, not power). If that is good, put an ohm meter across the other terminals on the relay and check for cont. with the key on. If that is bad, replace the relay. If that is good, then you have a problem in the wiring from there down to the starter.

did you check the big fuses up under the hood at the firewall.that vats is something you could have the fuseable link by the starter..my moms pa. done that....

Thanks Morley I'll make sure to check that next time I get out there. We had checked the relay before and there was the same resistance as the key on the wires going into the relay...we'll check again with the info you've given. Hopefully we can get out there tonight, but I'll keep you updated!

We checked fusible links close to battery...and fuse box under steering column. Mine doesn't have any fuses under the hood next to the firewall (I'm almost positive...but I will look again to make sure)...do you mean the two relays?

We checked fusible links close to battery...and fuse box under steering column. Mine doesn't have any fuses under the hood next to the firewall (I'm almost positive...but I will look again to make sure)...do you mean the two relays?
Well, if you were able to jump the terminals on the solenoid and make it start, then the fuseable links are good.
Those things on the driver's side on the firewall are indeed relays.
Have you tried a new start enable relay? If not, try removing it and run a jumper across the power wires going from it to the starter and see if it will crank up then. If it does, try replacing the relay. If a new relay doesn't fix it then you have a problem with VATS energizing the relay.

Morley-thanks for your help so far...you've been great! :)

Update: We grounded the starter enable relay with a jumper wire with a good ground and the motor turned over. We went back to the VATS and used same jumper wire with a good ground in the VATS main ground and the motor turned over. We also took a multimeter and checked the ground and it is showing 10V. Being a ground...it shouldn't be reading 10V, correct?

We followed more wires and the fuel pump relay ground also has 10V. When we jumped the wire with a good ground the relay clicked.

We checked the ground wire from the negative battery cable to the fender and motor and the ground wire from the firewall to the motor and ALL are good grounds.

Where do all the ground wires come together at for a good ground at the body?

The "main" grounds are on the back of both cylinder heads. Why you are getting 10V on those 2 relay's grounds is beyond me. Check your schematics and see if they share a common ground. If they do, then somewhere along there it is shorted. Check for pins in a connector making contact thatthey shouldn't be.

No dash lights are coming on now when switching the key on except the brake light and the seat belt light.

Have you checked the 20A fuse in the holder by the battery and the ECM fuse in the fuse panel?

Check those and report back.

In the mean time, can someone answer why there is no option for me to attach files?

More than one way to skin a Camaro...

I'd suggest starting at the top to figure out why no SES light first. Could be simple as a couple of fuses/no power to ECM.



http://webpages.charter.net/whoaru/Pg1.jpg

http://webpages.charter.net/whoaru/Pg2.jpg

http://webpages.charter.net/whoaru/Pg3.jpg

http://webpages.charter.net/whoaru/Pg4.jpg

Have you checked the 20A fuse in the holder by the battery and the ECM fuse in the fuse panel?

Check those and report back.

We did check those two fuses and all fuses as stated earlier in the thread. Thank you for your input however, and the diagrams you provided. We will check both CKTs 340 and 439 again per the diagram but it shouldn't be CKTs 340 or 439 since the motor will turn over (being that CKT 340 is for Battery Power In, and we have battery power and CKT 439 is for Ignition Power In, and we have ignition power when we use a good ground on certain relays).


Update otherwise-
We are still following the ground wires (when we can get out there) to find out where we are losing connection. The other day when we went back out, we were getting intermittent good ground and 10V ground on the wires that we had previously said certain relays were getting a ground of 10V. As soon as we went out, we took off part of the wire loom and checked some wires and rechecked the relay grounds that previously had 10V and they showed on the multimeter 0V. Ten minutes later, we were moving some wires around in the wire loom and then they were 10V again. We believe somewhere in the line ground wires may be kinked, perhaps when we set the motor back down into it after rebuilding.

Have you checked the 20A fuse in the holder by the battery and the ECM fuse in the fuse panel?

Check those and report back.

We did check those two fuses and all fuses as stated earlier in the thread. Thank you for your input however, and the diagrams you provided. We will check both CKTs 340 and 439 again per the diagram but it shouldn't be CKTs 340 or 439 since the motor will turn over (being that CKT 340 is for Battery Power In, and we have battery power and CKT 439 is for Ignition Power In, and we have ignition power when we use a good ground on certain relays).


Update otherwise-
We are still following the ground wires (when we can get out there) to find out where we are losing connection. The other day when we went back out, we were getting intermittent good ground and 10V ground on the wires that we had previously said certain relays were getting a ground of 10V. As soon as we went out, we took off part of the wire loom and checked some wires and rechecked the relay grounds that previously had 10V and they showed on the multimeter 0V. Ten minutes later, we were moving some wires around in the wire loom and then they were 10V again. We believe somewhere in the line ground wires may be kinked, perhaps when we set the motor back down into it after rebuilding.

i took a pa to good year and they hooked it up and said there was a ground wire breaking down but they never could figure out where . but it would run right on machine but i figuered it out my self. one guy said fuel pump then another guy said coil pack it wasn't so i took a chance and it was the module under coil pack the ground wire running to module so i think thats your problem..

do you have 12v at the ignition switch?
does the switch test out with relevant voltage in all of it's positions?
Does the car actually start when you jumper the starter?
Oh no there's no fuel pump power either I see.
Not sure if the BCM does any of the controlling relevant to your condition.
Definitely seems like you pinched wires when you reset the motor. There should be obvious marking in the loom if you did this...have a good look around.
You also state that "When we can get out there"...what do you mean by this?

when your trying to start it the starter take so much power away from fuel pump.dose it turn over at all?

i took a pa to good year and they hooked it up and said there was a ground wire breaking down but they never could figure out where . but it would run right on machine but i figuered it out my self. one guy said fuel pump then another guy said coil pack it wasn't so i took a chance and it was the module under coil pack the ground wire running to module so i think thats your problem..

this vehicle doesn't have a coil pack, it has a distributor...thanks for replying anyway though :)

do you have 12v at the ignition switch?
does the switch test out with relevant voltage in all of it's positions?
Does the car actually start when you jumper the starter?
Oh no there's no fuel pump power either I see.
Not sure if the BCM does any of the controlling relevant to your condition.
Definitely seems like you pinched wires when you reset the motor. There should be obvious marking in the loom if you did this...have a good look around.
You also state that "When we can get out there"...what do you mean by this?

Yes, we have 12V at ignition switch.
Yes, the motor turns over, but it doesn't start.
"When we can get out there" means...we both have full-time jobs and can't get out there to look at it all the time, so....when we can get out there...we get out there...lol.

Ok, turns over but doesn't start is news to me, I had thought it only turned over when the solenoid was jumped. If they key will turn the engine over then VATS and all related things are NOT an issue.
Since you said you had the engine up/out....check the harness connection for the distributor, the connector is about a foot or more from the distributor.
If this is good, check for spark. If spark is no good, track it down (voltage into coil & out of coil). If spark is good, get a noid light and hook it to an injector connector and crank the engine, it should flash as the engine is cranked (check a connector on the left and right banks). If it doesn't flash, this means that the ECM isn't firing the injectors. Check inj1 & inj2 fuses on the fuse box. Remove the ignition module and have it checked. The ignition module sends a refrence pulse to the ECM to let it know the engine is turning so it will turn on the injectors.

OK I see...thanks for clarifying.

I read the original post again....
Now if there's no power at the fuel pump relay...I'll assume that the fuel pump is not running...the car can turn over for eternity and never will start.
That needs to be addressed. Whether it be by re-wiring it or whatever you have to do to get fuel to the fuel rail.
Now you say that there is power to the distributor...but is there power at the spark plugs when you turn the car over?
If there is a spark then the only problem for starting the car is the fuel related.
Injectors can be tested but it's unlikely that all 8 are bad all at once.
only a misfire would relate that...unless the whole unit is not responding.
But not getting fuel is a major issue.

On a side note: some ground wires in a vehicle WILL read with a + voltage until the wire is actually used in a circuit...I couldn't tell you which ones....being unfamiliar with your vehicle but my 00 firebird puzzled me with that while installing my alarm/starter.

Let us know about the spark and fuel positions and we can take it from there.
the hardest part about helping is not actually being able to put yur hands on the car.
sorry about that....but we could help much quicker with the car in hand...I kow you know that but...lol...just saying.

yes it got the hei dose'nt it? it can still be in the pickup coil or just the coil in the top...

i would check the power and ground supply to the ecm i had a customer bring one of those f bodies and i noticed the engine light was not coming on then i found no power to the ecm it was a broken wire under the hood passenger side running on frame rail

OK I see...thanks for clarifying.

I read the original post again....
Now if there's no power at the fuel pump relay...I'll assume that the fuel pump is not running...the car can turn over for eternity and never will start.

On a side note: some ground wires in a vehicle WILL read with a + voltage until the wire is actually used in a circuit...I couldn't tell you which ones....being unfamiliar with your vehicle but my 00 firebird puzzled me with that while installing my alarm/starter.

Actually the car SHOULD start, even with the relay not working. The oil pressure switch is a backup for the relay. Once it sees 7psi it closes and energizes the pump.

Some "grounds" will have voltage on them, they are floating grounds, ie headlight motor wiring, door lock wiring..etc.
The start enable relay and fuel pump relays are not supposed to have voltage on their grounds..and he only has 10V instead of 12, so there is a partial resistance in there, not a hard short.

Ok, turns over but doesn't start is news to me, I had thought it only turned over when the solenoid was jumped.

Yes...this is true, astrosurfer asked if it turned over when jumped the starter off and I said yes, the motor turns over...but the car doesn't start. Remember when we said that certain things weren't getting a good ground, such as the fuel pump relay was reading 10V instead of 0V and the start enable relay was showing 10V, not 0V? Giving each of those a good ground manually with a jumper wire created the 0V ground that these relays needed and therefore the car was able to crank with the key but didn't actually start because there isn't any fuel coming. Remember? :popcorn:

...he only has 10V instead of 12....

Not that it really matters...but I'm a she...not a he! :evillol:

Injectors can be tested but it's unlikely that all 8 are bad all at once.

Mine only has two injectors (TBI), not eight. :nono:

so you got the carb not multiport? well did you spray any carb cleaner in it or run any sea foam threw gas tank? like i say i run sea foam in my bike and i've never had any trouble using it in my cars and trucks either. and if i'm the one that i thought you man and not women. if so sorry.

seafoam or carb cleaner will not solve her no start situation.

ok if you say so. what would you say?

Not that it really matters...but I'm a she...not a he! :evillol:
Either way I'd loose. I work with a Guy named Ashley...50/50 chance.

. Remember? :popcorn:
No, I don't. This has been a long running thread with several days of no new posts in between.
Hows about a summary of all the parts you have tried so far? As in parts replaced. I know you mentioned an ECM. As it is looking, since you said the engine was up or out and put back and now it is having problems, you may have to pull the engine up/out again to see what wiring bundle you could have pinched back behind the engine (there should be 2 big ones back there).

i'm sure i could go back to the beginning and re-read, but have you performed any fuel pressure and spark tests?

Mine only has two injectors (TBI), not eight. :nono:
OK
I understand
like I said tho'...I'm not too familiar with your setup. (or did I say that?)
You did not answer if you have a spark?
Having a spark really points to a fuel problem in my understanding of a combustion engine.
fuel/compression/spark(ignition)/exhaust
In that order....
so...if you're sure it has compression...then it must have exhaust..(in order to allow it to continue to turn over)
next has to be the spark test....If ok..then the only other factor is fuel.
have you tried squirting some gasoline into the throttle body? maybe even some starter fluid to test for fuel ignition?
screw all the filter and stuff for now...let's get some fire going...lol

like I say it's hard without the car....
It's way too easy to speculate here and throw out big technical ideas, but without all the basics covered we're all in the dark and guessing.

basically if you have no fuel pressure...it's never going to start.

I'm sorry I haven't posted in so long, we haven't been able to work on the car until today...so I finally have some new information.

Found the ground wires behind the motor, and car will turn over with the key now! YAY!! It will only turn over, but will not crank however. No fuel, so no crank. Tried putting gas into the throttle body several different times and it sputtered.

Try using starting fluid (ether in a can), just pouring gas in the throttlebody is not as effective.
Have you looked down the throttlebody while cranking to see if there is fuel being sprayed in there?
Also, when you turn the key, do you hear the fuel pump run for 2 seconds?

good to see you managed to do some more....
seems it's not as much a priority getting it running as it would be for me....it would eat and eat at me til I got it.
sounds like the only issue now is the fuel....
hope you figure that out.....like have you tried just hotwiring the pump for a temp measure to get fuel to the motor...this looks to be the problem to me.
I'd just hook it up to a relay with the ignition wire for temp til I got it running...then diagnosis might be easier.

still wishing you the best of luck figuring it out....would love to get my hands in the car.

Morley-There isn't any fuel coming out of the injectors, and the fuel pump doesn't prime while the key is in the ignition in on position.

Astrosurfer-would hotwiring it work?

I must be quick here...the hurricane is above me...
hotwiring it ...you must isolate it from the bcm first....i.e. unplugging it from wherever the plug is.
being that the pump runs on 12v....there should be no trouble in direct wiring to check for operation.
but I stress isolating from the bcm or whatever it runs through.
I can't go into great detail about wiring right now but a 4 pin relay would work as a temporary fix if the pump runs whilst directly wired to 12v.

85= ground or + from IGNITION..(hot in run and start)
86= ground or + (opposite from 85) unless a diode is present.
87= ground from pump
30= wired to ground

85 and 86 may be other way around but one will be + frim IGN and other should go straight to ground.
but before wiring the relay you should test for power with a quick check direct connect...careful not to mix + and - and burn the pump...a test meter will help this.

I have to go now....getting bad around here...good luck with it and I'll check back as soon as I can.

ASTRO

Run a wire from the positive of the cig lighter to pin G on the ALDL, this will power the fuel pump. see if it starts then.

Run a wire from the positive of the cig lighter to pin G on the ALDL, this will power the fuel pump. see if it starts then.

I came in for a minute to look for another ALDL diagram, we looked in the manual and it said to jumper a wire to terminal G on ALDL (same as you, as I just read) and in the picture it showed a pin in there...mine doesn't have anything in pin G...but just to make sure...we stuck it in there anyway, and nothing happened...lol, of course!
According to the diagram there are pins in A, B, D, E, F, and G. Mine has A, B, D, E, F, K, and M...this manual is for 1982-1992, so the diagram could be incorrect for mine? (There is no I terminal per diagram)

Also have a new troublecode that is code 54-fuel pump circuit (which...we already know that there is a problem...but at least my check engine light is working again...progress! :D

We will look into your idea Astrosurfer- STAY OFF the computer while the hurricane is above you! GEEZ!! :)

I came in for a minute to look for another ALDL diagram, we looked in the manual and it said to jumper a wire to terminal G on ALDL (same as you, as I just read) and in the picture it showed a pin in there...mine doesn't have anything in pin G...but just to make sure...we stuck it in there anyway, and nothing happened...lol, of course!
According to the diagram there are pins in A, B, D, E, F, and G. Mine has A, B, D, E, F, K, and M...this manual is for 1982-1992, so the diagram could be incorrect for mine? (There is no I terminal per diagram)

You will have a pin in E & M, they are spliced together behind the ALDL connector. Pin E is for 160 baud and pin M is for 8192 baud communications, but either one will do either baud.
Sounds like someone moved a pin from G to K on your ALDL

keep up the good work...progress is good.
hurricane is gone now and waiting to see what IKE will do.
came out OK from GUSTAV. Local city did not...BATON ROUGE got pretty tore up.

let us know about the fuel as soon as you figure it out.
you should be able to start the car when you figure the fuel out.

still wishing you luck.

Any progress on this car yet?
Be nice to know if any of us helped in some way to resolve the issues.

Let us know what's going on please...Thanks.

Well...ha ha...actually we had a different problem come up that is currently lagging our progress on the Camaro...the 60 mph winds we had from a storm messed (actually..ripped) up the roof and when it rained, rain was pouring in the shop...messing up everything, so we had to stop work on the Camaro and fix the roof. Done with one side of the roof (the worse side), and haven't had a pretty day to work on the other side of the roof. However...when we were messing with the roof, the electricity started sparking and smoking, so we had to shut the breaker off so no more electricity would go out there (darn ppl and their bad wiring jobs..pff!), and so we are currently at a standstill on the Camaro. :( Glad to see that you are still interested in the outcome, sorry to deliver bad news.