91 Camaro Starting Problems

ashley51071 · #1 07-26-2008, 07:46 PM

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!

Whoaru99 · #2 07-27-2008, 04:50 PM

Quote:

Originally Posted by ashley51071

...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!

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?

Morley · #3 07-27-2008, 05:40 PM

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

ashley51071 · #4 07-28-2008, 08:47 PM

Quote:

Originally Posted by Morley

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?

ashley51071 · #5 07-28-2008, 08:49 PM

Quote:

Originally Posted by Whoaru99

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.

Morley · #6 07-29-2008, 01:53 AM

Quote:

Originally Posted by ashley51071

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.

ashley51071 · #7 07-29-2008, 04:33 PM

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?

ashley51071 · #8 07-30-2008, 07:55 AM

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.

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

Morley · #9 07-30-2008, 07:45 PM

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.

Scrapper · #10 07-30-2008, 09:01 PM

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....

ashley51071 · #11 07-31-2008, 01:11 PM

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!

ashley51071 · #12 07-31-2008, 01:15 PM

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?

Morley · #13 08-01-2008, 01:02 AM

Quote:

Originally Posted by ashley51071

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.

ashley51071 · #14 08-03-2008, 03:59 PM

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?

Morley · #15 08-03-2008, 08:11 PM

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.

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