fairlane11

Hello everyone, I bought my first camaro yesterday. I have a 1991 RS v6. I can not get it to run. I have read just about every old post and learned alot already. The fuel pump will not run. I have drained the tank,replaced the pump and sock and still no go. I have 12 volts when key is switched on for about 2 secs and during cranking its flashing about 8 volts on the tan wire. There's 3 total. Should there be any other voltage on the other wires? What am I missing? If anyone could help I would appreciate it.

ASE doc

Check the ground to the pump. It's the larger of the two black wires in the tank unit harness. The easiest way to test grounds is to use it as ground when testing a 12v circuit that you already know to be good. Use a paper clip with one end sharpened so that it can be inserted along side the ground wire. Attach the ground clamp of the light or DVOM to the paper clip and proceed with the test. If you determine that ground and power are good outside the tank, remove the pump and bench test it by very quickly powering it up through the harness. Look for a poor connection somewhere. Do not dry run the pump for more than 2 seconds at a time.

fairlane11

OK, I got the pump working,turns out it was the connection between the plugs between the outside and inside the tank. Thanks.

fairlane11

Now I have fuel in the rail and spank but still not running ??? The car has been sitting for a couple years from what I can tell. I am going to run get plugs and see what happens. Are there any tricks other than norm for these cars. The car does thy to start with some started fluid in the throttle body.

ASE doc

Definitely check state of tune. You have fuel to the rails, what's your fuel pressure? Do you hear the injectors click? Test injector pulse with a noid light. Your 91 is speed density isn't it? Speed density meaning that it has a MAP sensor and no MAF sensor. If it had a MAF sensor, I would be concerned that the MAF may not be registering air flow. Thus, no fuel from the injectors.

Air_Adam

Just a thought.... doesn't VATS keep the fuel pump from running if it thinks theres a problem?

ASE doc

No, VATS does not prevent the pump from running but it does prevent injector pulse. that's a very good point Air Adam. Does the Security Light flash when you're trying to start the car?

fairlane11

The security light comes on as does the pump when key is switched on. During cranking the security light goes off. I will have to borrow a fuel pressure guage to know the fuel pressure, but the fuel hits the hood when I press on the port on the rail. I would think that's good pressure. I can hear clicking when the engine turns over but I am not sure if it's the injectors or the distributor. I think its the distributor. Is there any way to check injector pulse without a noid light?

ASE doc

You can check injector pulse with a 12v test light.

fairlane11

cool,thanks for the info.

ASE doc

One thing though about VATS is that it also disables the starter. The start enable relay may have been bypassed though. See if you have injector pulse and we'll go from there.

1969RSSS

Did you drain out the old fuel? if not you may want to do so and add some freshy fresh fuel then pull the plugs and check for wet tips.

fairlane11

OK, I have constant voltage on the striped wire with the ignition on. The solid wire pulse's when engine is turned over so I am saying the injectors are firing. So if if I have fuel in the rail,fire on the plugs, and air getting in it should run. I am open to any and all suggestions. I do not know the fuel pressure yet but will in a bit.

fairlane11

yea I sucked it dry with a wet vach.

fairlane11

I cranked the engine about 5-10 seconds and pulled the 3 plugs on the driver side and they are all dry.I dont know how mush presure is on the rail yet. I'm waiting on a buddy that has a gauge.

fairlane11

OK, I got the gauge and I have 47 LBS on the rail. I am going out to pull the injectors and try to clean them. It looks like I can access them by just pulling the upper intake. If anyone has a better way I'm all ears. Thanks.

ASE doc

So you have injector pulse and spark. 47 psi fuel pressure and dry plugs. I dont remember you saying if this is a MAF car. If it has a MAF sensor, try unplugging it and starting the engine that way before you pull the upper intake. Do you have spark on more than one plug wire? Did you check injector pulse on both banks? If you do pull the upper intake, use an ohmmeter to test the injector coils. They should test at 12ohms minimum. Shorted coils are common.

fairlane11

Sorry, It is a speed density motor. I have the rail out of the car and the injectors look ok to me. I started another post asking how how to clean them. I was wondering about the best way to bench test them. I was told by a buddy they only take about 5 volts to work and not to put 12 volt to them. I was thinking about a 9 volt battery but I don't know if it would work? I just dont think they are bad enough to keep it from running. I am new the chevrolet's. I am OK with ford's but this should not be that much different. I do appreciate the help. You seem to be knowledgeable about these cars no I'm kinda leaning on you ASE doc. Thanks again.

ASE doc

Are you the one who's sending your injectors to South bay?

The injectors are 12v devices. Im glad you didn't try to bench test them. They are inductive electromagnetic coils and become saturated very quickly. Once they reach saturation, their current draw goes high and they become hot. This can damage the coil. Aside from "clicking" them with a touch from a 12v test light, powering them up outside the quad driver network is not recommended. They do make an injector tester that activates the coils in the same way as the quad driver but generally, once i know the coil shows good resistance, I leave the rest to the experts, like South Bay.

I am a 35 year ASE Master technician L1. I do have a fairly deep understanding of automotive systems in general and some specific knowledge of GM products because of the time I spent as a GM engine performance tech. There are guys on this forum who spend a great deal of time working on these cars and are very studied in the systems involved. As much as I may help others, I learn something new almost everyday. I know that if you follow a logical path, we will get your car running.