So I had a 91 camaro rs TBI that had a messed up body. I bought a roller, 88 Camaro rs. Stripped all the engine bay and put everything from the 91 on there. The car started right up with the 88 ecm. So I decided to annoy myself by installing the interior harness from the 91 on the 88. Connected everything just about right. Only things left unconnected were the air bag and the hatch release motor since they are not the same. I connected everything and connected the 91 ecm and the car won't start. The car wont crank and I don't even hear the fuel pump, which was working fine after installing the engine and transmission. I know its very complicated but does someone have an idea of what it might be? I've been working on this for 6 months and I'm dieing to drive my car.

 

VATS?

 

Yup vats 89 up

 

I'm not sure... I don't have a chipped key and the 91 started just fine. I connected everything how it was and it won't start. But it did before without a chipped key

 

Is the mil hooked up so you can blink codes ?

 

I have no idea what you just asked me man, sorry. I appreciate your help.

 

does the check engine light work ? You can jumper the aldl connecter a to b to read codes.
http://www.obd-codes.com/faq/read-gm...codes-free.php

 

It did but I took the cluster apart because I purchased an intellitronix panel.

 

I would start with the no crank first, do you have power at the starter enable relay large green or yellow wire ?

 

Yes I do

 

How about after c100 ?

 

Im not sure about that one. It should. How do I figure that out?

 

With the fuel pump not running and the engine not cranking, it isn't VATs. An '88 Camaro doesn't have the starter interrupt relay.

Check the fusible links at the starter. Power has been lost somewhere along the way. The bulkhead connector may have been pinned differently between the years.

RBob.

 

Only the body is 88. All the wiring is 91. I was messing with it and the fuel pump turned on when I put it on reverse but still no crank.

 

Since you changed all of the wiring you need to use the '91 key with the pellet in it.

As for the fuel pump and reverse, there is a wiring error someplace.

RBob.

 

That's quite a theft deterrent system lol

 

The keys didn't have pellet. They seemed like they were made by a locksmith.
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😂😂😂 Its somewhere in the interior. I know everything under the hood is right, but I'm not so sure about all the electrical mess, everything seems right but there is obviously something wrong.

 

I take it that you are using the '88 key & ignition key cylinder? Either way the '91 has VATs, which you swapped into your car. Now it too has VATs. An ignition key without the pellet won't work. Unless of course some items are bypassed.

RBob.

 

No... When I use to drive the 91 camaro I used the same key without the pellet that I am trying to use right now. I switched the steering column as well.

 

Where is the bypass resistor for the VATS located? Did it get switched with the rest of the wire harness?

Were some '91s not equipped with VATS?

 

I'm sure it had vats. It has all the vats wiring but I think it was somehow bypassed.

 

If the 88 ecm is being used there would not be vats for the ecm. But if the passkey module is installed the enable relay may be effected unless bypassed. Sounds more like c100 differences.

 

I used the 91 ecm. But I did try the 88 first, on accident

 

The car also seems to be getting 12v continuously. As soon as I connect the battery my parking lights turn on. And I have them turned off at the head light switch. I'm working on it right now trying to see which wire was connected wrong, or why am I getting power to those without the key being on.

 

The parking lights and the fuel pump oddities sound like there is a ground problem. Check all of the grounds in the engine compartment and under the dash.

RBob.

 

So I tried to hot wire the starter and nothing. The starter works but the engine still doesn't seem to want to start. I heard it start so I know it works. I heard it start with the 88 interior wiring. I put the 91 wiring and steering column and nothing. I'm starting to think there are connectors that aren't compatible because of the year difference. The only thing that I didn't switch from the 91 is the gear switch. I'm going to search to see if that might be the problem. All the harness looks right about right. Nothing seems to be off. So fuel pumps on reverse and starter doesn't start the car. I tried it on neutral reverse and parking. Could it be the gear switch connector?

 

The gear range switch has nothing to do with the fuel pump, unless there is a wiring error. That switch will affect whether the starter cranks or not. As it opens the S wire to the starter solenoid unless in park or neutral (so it doesn't crank/start in gear).

RBob.

 

The '88 & '91 c100 connections don't match

If you have an '88 you have to use the '88 harness.
If you have an '89 you have to use the '89 harness.

'91' & '92 will interchange but that's all.

 

Where does this harness connect to? Does it go out into the engine bay on the drivers side? Why would it not work if all the wiring is 91?

 

Yes on the left side in the engine compartment.
From year to year they changed the wiring on the dash side.
The connections therefore don't match.

 

But all my wiring is 91. I installed all the wiring from the same 91 car on the 88 so I don't think that's the problem. I did however find a ground cable not grounded. I ran out of time but I will ground that cable and let you know if that was my problem. My fingers are crossed and again, thanks for your help.

 

You got me there, I wasn't aware you could put a '91 harness inside of a '88.
I guess keep searching for the missed connection.

 

I tried to start the engine by turning the starter with cables and it works but the engine doesn't move. I'm hoping its not reaching the flywheel. And I no longer hear the fuel pump. 😬😬😬 I am officially annoyed.
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WHERE are you making connections at the starter? What sound(s) do you hear when the starter runs?

Fuel pump fuse popped? Any power to the fuel pump fuse? Fuel pump relay toast?

 

I'm fearing I may have triggered vats to work or a relay or fuse isn't working. I have power throughout the whole car except the cluster area, including the ignition switch. Where is the fuel pump relay located on a 91 305 TBI? And also, is there any relay or fusible link that feeds the cluster and steering column? I want to see this think out on the road already. Any help will be appreciated.

 

The former relays next to your master cylinder on the bulkhead. The up gets its power from a switched ign at the fuse box.
Illumination from the headlight sw.
Stop hazard,is one one fuse , turn is on another.

 

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master cylinder? I have an automatic transmission. Where the hell is the master cylinder?

 

Also can someone tell me, or send me a link that will explain, how to completely bypass vats quick and easy? I will bypass it to scratch it out the list.

 

Brake master cylinder next to the lh fender on the bulkhead.
Post 8
https://www.thirdgen.org/forums/tech...-no-start.html
You will need to bypass the starter enable relay as well.
You need to jumper or connect the two outer wires green and yellow or purple . The wires are the larger gauge ones. The relay is under the drivers side kick panel maybe under tar tape.

 

 

Nothing I do works. I've been working on this car for ages now. So I'm still trying to get rid of vats but havent actually started the procedure. Did some reading and saw something about a prom. I still have the 88 ecm. Can I get the prom from there and put it in the 91 ecm?

 

Also, does anyone know what this is? Its the only relay I haven't figured out.

 

Looks to be in the interior someplace. The general area of where it is located helps to narrow down what it is for.

RBob.

 

Its around the fuse box. On the drivers side to the left of the steering column. That's the only connection that I never found. I'm hoping it helps me start it. Tomorrow I am going to go to a junk yard to see if I can find a camaro like it and look at the harness and take video. Hopefully I get some answers

 

Looks to be for the fog lights relay.

RBob.

 

I put in the prom from the 88 computer and nothing. The car doesn't seem to be getting any power. When I put the key in the ignition nothing turns on. Only the lights turn on when I connect the battery. What gives the ignition switch power?