QuestionOk I tried all this. There are four wires going to the fuel pump relay. One is the power that switches the relay on and that goes into the ground that is hooked to the ecm. This one is not working. There is a pinkish wire that gets 12 volts when the ignition is turned on and this one is the one that the relay (when triggered) goes to the fourth wire that powers the relay. I can use a jumper wire and not use the relay and get the pump to work when I turn the key on. The injectors have power to one side of the injector when the key is on. If it was an old non computer carburated car it would start. Since the fuel relay isn't getting the power to trigger it, but when I bypass it the car still won't start I'm just not sure what to check or replace. Is the electric fan supposed to come on when the key gets turned on. One time only did this happen when I was testing different things for voltage. This seemed weird to me, but maybe the fan is supposed to turn on when the car is first going to start. This is why I am wondering if the ignition is worn out. Something is stopping the car from starting normally. Like I said before, I can spray starter fluid into the throttle body and the car tries to start then, so whatever controls or turns on certain electical functions is not working. I know I'm close I just need some electical knowledge for this car. I know you can help.
Thanks again.
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Followup To
Question -
Thanks Van.
I will check that, but would other stuff work off the ignition if the fusable link was blown. I can get power to other things when I turn the ignition on, but not to the fuel relay and possibly other relays. I would think that if the fusable link is blown, then nothing would work from the ignition. I may be wrong.
Thanks again.
Jon
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Followup To
Question -
Hello Van.
I have been reading through your responses and you seem very knowlegable. My friend has a 87 buick park avenue that ran when she parked it, but when she went to use it and sell it, it wouldn't run. Here dad repaced the fuel pump because it wasn't getting fuel, but it still didn't work after he replaced it. Heres where I come in. I went through my normal process and checked the fuel pump fuse and it checked good. I next checked the fuel pump relay and that is where the problem lies. The relay is not getting the power to turn itself on so the pump will work. I can bypass the relay and get the pump to work, but the car still won't start. I think I have it narrowed down to two things. Either the computer went bad or the ignition switch is bad. I believe this because the car has spark compression and fuel (when I bypass the relay). I can get the car to fire for a few seconds by spraying ether in the intake, but I don't like doing that. I am kind of at a stand still because the car isn't worth a whole lot and I don't want to put money into it if it isn't the problem. I am hoping you can help me. My thought is its the ignition switch because no relays are clicking on when the key is turned. Thank you for any help you can give me.
Jon
Answer -
Check for a blown fusible link that supplies power to the ignition switch.
May be a fuse, probably marked ign.
Van
Answer -
The fuel pump relay has its own fusible link, separate from the ignition switch.
It has battery power to the relay all the time. When you turn on the ignition switch, you send control power to the relay. That is the power that operates the relay.
I believe orange is the color of the power wire that should be hot all the time. It also goes directly to the oil pressure switch.
There should also be power to one side of each injector when the key is on. The ECM completes the ground path, operating the injectors.
That oil pressure switch sends full battery power to the fuel pump once oil pressure builds to 4PSI, reguardless of weather the fuel pump relay works, or even if the ECM isn't working. It is just a pressure switch, connected directly to the battery by a fusible link.
So check the orange wire for power.
Also look for an inj fuse if there is no power to the injectors with the key on.
Van
AnswerHave you tried a "noid" light on the injectors?
When cranking the engine, the noid light is supposed to blink, meaning the ecm is closing and opening the ground from the injectors.
If you have power to the injectors, and fuel pump pressure, I don't think the ignition switch is the problem, although that possibility still exists.
The ecm gets a signal from the crankshaft or camshaft position sensor. That is how it knows exactly when to fire the injectors.
Here is a thought.
You say there is power to one side of the injectors when the key is in run....but have you checked to see if there is power there when the key is in crank? Needs to be.
Same with power to the ECM.
Van
