i posted this in another board not long ago and i now believe it may have been the wrong board to do so. i apologize. hi ive got a 90 camaro rs v8 LO3 and i cant get her to start. she worked fine and then i got her new spark plugs. afterwards she wouldnt start. i know the plugs and wires are where they should be. the problem from what i can tell seems to be a electrical problem. for whatever reason the injectors arent being told to spray fuel, but i cant figure out why. i have already installed a new ECM and still nothing. can anybody help me . i've been without my car for going on 3 weeks now

 

are you getting fuel?.fuel pump working? have you checked injector relay?
changed ecu but is the signal making it to injectors?(buddys car had break in his wire between ecu and injectors)

 

yea the fuel pump is straight and the fuel lines are under pressure. couldnt find a injector relay. do u know where it is?

 

Injector relay?

Check the wiring harness to the injectors, it could be as simple as that.
Also, check the wires to the distributor and coil. If the coil signal doesn't make it to the ECM, it won't fire the injectors, so that matters too.

Have you checked all the fuses yet?

Next step would be to start checking voltage on injectors and ignition components (coil + distributor) and also spark.

Lou

 

well we took another shot at it today. alternator came up shot so got that replaced. a few friends of mine have brought up the possibility and there being a problem within my passkey system. can any shed some light on this? anyone had problems with theirs and it causing there car to turn over but not start?

 

Your friends were talking about VATS (Vehicle Anti-Theft System). If the right key isn't inserted into the ignition, the ECM won't fire the injectors and the car will crank without starting.

It's unlikely that by putting new sparkplugs in you'd cause a failure in the VATS. But it's not uncommon either.
You need to rule out other possibilities.

Why don't you spray something flammable down the throttle body (like a brake parts cleaner or carb cleaner) and see if the car starts shortly? If it does, your spark is ok and you don't need to worry about that.

Have you checked all fuses yet?

Lou

 

i sprayed some starter fluid down the tbi ans she did start but cut right back off. i can hook the injectors directly to power also and they spray gas. my friends are thinking that there is an issue with that vats thing. they think it may be dead or a wire from it to the ecm is messed up. would this cause my issue?

 

Yes, it could be VATS (it could be anything, for that matter ).
Do you have power to the injectors with the key on?

You can do a search on VATS in this forum and you will find a LOT of info and troubleshooting tips. There are ways to fix it and there are ways to bypass it, it depends on what you want to do.

Lou

 

no when i turn the key on i get no power to them. is there any other electrical components that would cause the same issue? if it is the vats how much does a shop normally charge to fix it?

 

Before you spend a hundred or so on labor costs troubleshooting and fixing the vats system, it's fairly easy to bypass if you follow the instructions online. IF it works when bypassed. then you know the problem is at that point up to the key lock. Could even be the key, itself. Check resistance, compare to standard. If it's good, then do the bypass, see if that works. You should be able to follow the directions and avoid costly shop charges.

 

For a VATS fix, a shop will normally charge you so much that you'd have to sell your car to pay for the fix. Kinda defeats the purpose.

BUT if you don't have power to the injectors with key on, something is amiss in the injector circuit. Check the fuses!! (you never answered that question)

Check the injector wires too. All four should have 12V on them (with the key ON) when you test with a DMM or if you use a test light, the white and red wires should light it up, but when you test the green and blue wires, the injectors should spray fuel.

Hope this helps.
Lou

 

wow thats crazy. im sorry i must have missed that question but yes the fuses are good as well. where can i get a test light? do i have to take the wires off the injectors in order to test it? if so how will they spray fuel? where is the injector circuit located?

 

A 12V test light can be purchased at any tool store. The cheapest are $0.99, the expensive stores sell them for $5+. It looks like this: http://www.harborfreight.com/cpi/cta...temnumber=4288

Leave the injectors plugged in, turn the key on and probe all four wires with the test light as per instructions above.
If the injector fuses are good, you should see voltage on the injectors (not sure how you determined before that you didn't have power to them).

Lou

 

havent been able to get the test thing yet since i dont have anyone to drive me. just curious if there is there anything else that could cause this problem im having?

 

i did some more research around the site and i see that some brought up the issue of the ignition switch? possible the key is weak or loose? one thing i do know is that some, not all the time, when i put my key in and the chime comes on itll break up like it doesnt have power or something but the battery has a good charge. not sure if that helps .can anyone elaborate on the other possible causes if my car's illness?

 

ignition lock cylinder, as i understand has two wires coming from it. i understand that the wires commonly break. if one of the two was broken would it cause my car to crank but not spray fuel in order to start?

 

Correct.
It would be a bad coincidence to happen just after you were servicing the engine but it can happen.

Is your security light flashing or on while cranking?

Lou

 

the security light comes on when the key is moved foward but then shortly goes off. light stays off while cranking

 

Then it shouldn't be VATS.
Check the injectors when you get a chance.

Lou

 

yea we went back over it and we arent getting power to the injector wires. what could stop that?

 

Fuses, wiring, connectors .... you need to check the red and white wires from the TB into the harness and further to see why there is no power.

Lou

 

would a bad ignition control module cause this as well? any quick fix or parts that would cause the power not to flow? also do u know where i can find a engine wiring diagram for my LO3? its not in the haynes

 

A bad ignition module would cause a no-spark situation and thus no-injection situation as well (the ECM needs to see coil pulses, otherwise it won't inject fuel).

But you said you have spark, right?

Lou

 

yes i am gettin spark. so it could possibly be the pickup coil correct? my wires look totally intact. no cuts or anything that i can see. most of the parts on my car are the originals from 1990 just because the two owners before me weren't big on car maintenance.

 

Well, there is a possibility that a wire might be broken and the ECM doesn't see the spark signal. That wouldn't be caused by a bad pickup coil, though, because then you would have no spark at all.

If you need diagrams, we have PLENTY of them here: http://www.austinthirdgen.org/index.php?pid=19
For a 1990 Camaro, you can find detailed blow-up diagrams in the second half of the page, engine specific.

So when you tested the injector power wires (red and white), they had no power whatsoever? How did you test them? With the test light? Did you have a good ground on the clamp? (sometimes what seems to be a good ground, isn't).

Lou

 

if the wire was broken wouldnt u expect the wire to give when u pull on it? mine are all tight. we test the wires with a vom. with the car off,on position, and cranking and got nothing. what ground clamp?

 

If the wire is broken inside, the insulation still keeps it nice and tight, fooling anybody who tries to tug on it. So that's not a good way to test it.

If you had 0V on the injectors (all four wires) with the key on, you need to start tracing the two wires (red and white) to find out where the break is.

Start with this diagram: http://www.austinthirdgen.org/mkport..._injectors.jpg

The fused power goes across to the passenger side under the dash, hits the C207 connector (pins B and G) where it turns from pink/black wires to the red wire and white wire and then continues into the wheelwell and up by the heater blower cowling to the back of the engine and then to the TB. I'd probe the C207 to see whether you have power there. It's right next to the PCM, a two-tier connector, wrapped in a foam tape.

By ground clamp I meant how you grounded the testlight/voltmeter. The black alligator clamp needs to be on good grounded part (bolt, bracket etc).

Lou

 

finally got my car running, but now a new issue. it seems that my computer mayb messed up. that or the prom. when my car is on the check engine lights flashes on and off constantly. do i need a new computer or a new prom? or both?

 

So what was your initial problem, you didn't say?

As for your new problem, see this post https://www.thirdgen.org/forums/post...480-post2.html

 

o sry. yea the problem was a tiny fuse located on the passenger side close to the coolant reservoir. apparently it talks to the fuel pump and injectors as well. my haynes manual doesnt even acknowledge thats its there. looks like the computer issue is solved as well. pulled my prom and put it on another new ecm and she no longer gives me the check engine light flashes. of course as always once one issue is resolved another arives. my friend told me that all the old parts are seeing other parts being replaced and are getting jealous of the new parts. ha he just may be right but that issue is for another board. i wanna give a big thanks to everyone that helped me figure all this out. big extra thanks to BigBabyLou for the continuous help. i really appreciate it more than u know. 3RDGEN!!!!!!!!!!

 

This was one of the reasons why we wandered off the path. If I had known that you weren't getting any fuel, I'd have told you to check the fuel pump fuse on the fender.

But I'm glad you found it and that your car is already running again!
Lou