fbodygirl

Hello, well just want to make sure my ignition module and ignition system is working right. If the car won't start on it's own, only with starting fluid and runs fine untill it runs out of fluid, does that mean the ignition system is working correctly and module is working. I'm pretty sure I'm not getting a signal to the injectors to fire. Just want to eliminate the module from my list of things to check out. thanks

henryd3

iTrader: (128)

When you give it fuel and it runs fine until out of fuel, then you only seem to have a fuel problem. Ignition sounds like it's working just fine. Leave the module alone and figure out why you're not getting fuel

84transam87

can you hear the fuel pump prime when key in on posistion?

fbodygirl

Great Thanks for that info... and yes I can hear the pump prime and the relay clicks and I have changed the fuel filter so it's not restricting the flow of gas. I have also tested all 6 of the fuel injectors with a DVOM and they read 16 ohms.
So they are within specs. I don't have a noid light to check the injector wiring harness for voltage, so I don't know if the injectors are getting power, can I use just a test light or will that not give a good result? Thanks again for all the help.

84transam87

very possible fuel pump is not giving out enough pressure. might be the first thing to check.

91phoenix

iTrader: (5)

By it starting you just checked your ignition and it is fine. I would rent a fuel pressure gauge from autozone or someplace. My local Oreilly's did not have one with the correct GM schrader valve fitting, only for TBI. I ended up finally buying one. It sounds like a no fuel issue. It could be low pressure from the pump or FPR. All the next checks require a pressure gauge. A quick check to see if a leaking FPR is a problem is to pinch the return line closed and try starting. If it works then Fuel Pressure is good and FPR is probably bad.

Mine still isn't running but found it to still be the VATS even after I put a bypass in. Am once again waiting on parts, but at least they are ordered.

fbodygirl

Hello again, thanks for the help, 91phoenix, thanks for replying, I do believe that my car has a fuel problem. Called the local shop and it's 275.00 for the FPR and/or 600.00 for the Fuel Pump Repair. I'm leaning to the FPR. But I need to test it first. phoenix I don't have VATS in my car, so I dont' have to deal with that, but I do hope you get you car running, and me too. I'll let ya all know, what I find out. Thanks!


phoenix

ASE doc

fbodygirl, FPR failure is rare. Fuel pump failure is common. However, a fuel pump that primes and doesnt provide fuel for the car to atleast try to start is unusual. Be sure to test and verify the cause of the problem before spending money. Yes you can use a test light to check injector pulse. First , with key on, look for power at the injector, should have power on both sides. Then, while a helper cranks the engine, look for a flash on one side of the injector. You may have injector fuses or a fuse link thats open. Just because the ignition fires, doesnt mean that the ECM is recieving crank referrence pulses. The ppl/wht wire from the dist is the referrence out to the ECM. If this circuit is open or shorted, you will get just the symptoms you are getting now.

xch3no2

Oh My!
I hope we caught you in time girl, please listen to Doc on this.

Yes, as you indicated an ignition module failure can result in no-fire from the injectors, can be removed for testing by parts store or shop.
First check fuse & wiring.

Camaro305SB

My money is on the fuel pump....

Camaro305SB

double post, delete please

ASE doc

Any news? Please let us know where you are on this and what fixed it so others can benefit from your experience. Plus, I just hate the suspense. LOL

fbodygirl

Ha! that was funny doc! You made me laugh.... well, the update, Have tested lighted everything I can test. No light! I don't think I'm getting power to the injectors. I did probe the module and get at least a reading on my ohm, but other than that no light. I have check alot of the wires and their are no melts or corrosion. I'm still looking for something, let me know what ya think. Thanks

fbodygirl

Oh yes Double checked all fuses in engine comp and under dash, all check good...

xch3no2

Have the ignition module tested, repeatedly if it passes at first.

It's pretty easy to take out for testing..let us know.

fbodygirl

Hello again, well had the module tested a few times and it checks out ok, put it back in the car and still won't start. Pulled the codes and it only reads code 12 nothing more. How do I check the ECM side of the harness to see if it's sending any signal, still think I'm not getting power to injectors, but at a loss for now.

xch3no2

Well NUTS!
Gotta check fuel pressure, pump humming doesn't mean it's pumping.

Don't be discouraged, an answer exists.

I sure hope that tester checked both sides of the module.

fbodygirl

Hello, well I still can't find any power from the module or inj harness. I did take off the distributor cap and found that the pick up coil inside the dizzy is all rusty and looks like crap, and there is a plug that plugs into the back of the dizzy that has lost it's rubber boot cover and the wires are not broken but are exposed. Could a bad pick up coil and arching wires cause No power to the module to tell the ECM to pulse the injectors? I don't know anything about the dizzy and it's parts I'm learning all this from scratch, hope this makes sense, but like I said it did run on starter fluid so I'm confused...let me know what ya think, thanks

91phoenix

iTrader: (5)

You said that it runs on starting fluid. That tells you that the module is working. The distributor is working. One big question still needs to be answered. What is the fuel pressure? Assuming the injectors are firing it will not run without proper fuel pressure. When the first pump in my car ran it only put out 9 pounds. It needs about 40-45 lbs.
If this is good then it is (unlikely) FPR or a computer or electrical problem(likely) for the no start. It isn't hard to check the fuel pump pressure.
With the key in run I tested the wires to my injectors. The power to the injectors is not computer controlled. The computer controls the ground.
You said you have no voltage at the injectors. Is that on both wires or just one side. I used a sharp needle type probe to check mine. If no power on both sides then it isn't computer it is other electrical.

xch3no2

Mine was the same thought earlier, that it ran on outside fuel, so we expect the pickup to be functional.

Test w/ohm meter, 800-1000 ohm.

ASE doc

The dist can produce spark and still not provide the referrence signal, needed for injector pulse, to the ECM. Having spark does verify that the pick up coil and atleast half of the ignition module are functioning. However, in order to have injector pulse, the ignition module must send a crank referrence signal to the ECM. It sends this digital signal over the purple/white wire. Its in the 4 pin connector. The damaged wires you refer to could cause this symptom.

Now, something else. You say youre not getting any power to the injectors? Or just no pulse. Understand, the ECM closes the injectors by grounding the circuit. The 12v power supply is provided through the injector fuse, ignition switch and fuse link whenever the ignition switch is on. If you find on power at either side of any injector connectors, then you have a power supply issue that is seperate from any trouble with the ECM.

Do you have a good service manual with wiring diagrams? Use the diagrams to trace the circuits Ive mentioned above. Remember, 12v to the injectors comes from the injectors fuses, ground to the injectors is pulsed by the ECM.

fbodygirl

Well, it's been awhile since I could work on my car, because of the cold weather, but I'm back at it...UPDATE went and bought a Fuel Pressure Gauge Tester, and sure enough the needle on the gauge barely moves, so now I'm looking at a dead fuel pump. I can hear the relay turn on and a low buzzing noise, so I thought the pump was working. Are there any other tests to run, before I invest in a new fuel pump? Thanks for the help everyone.