Last night my car died on me. When I turn the the ignition on, the fuel pump does not charge. It turns over fine, all the fuses are good. I pulled the FP and put power to it, and it did run. Is there a relay I should be looking for??? I need to fix it now, I'm at drill and have to drive home tonight. Thank you. :cheers:

BTW, I am getting spark. :cry


[Modified by dtorc4, 5:24 PM 1/13/2002]

 

ttt

 

In an emergency, you can jump the oil pressure switch which will force the fuel pump on (pump relay will be bypassed). The fuel pump relay is on the left hand side of the dash right in back of the OD relay. Since you have spark, then the VATS must be working, also confirmed since you can crank the engine. The ECM operates the fuel pump relay (supplies 12 v to the relay coil) and might be the culprit.

 

ok, I found the cause. The fuel pump relay is not sending power to the fuel pump. To get the car running, I had to run a wire from the battery, through a fuse, to a switch I put next to the ignition. I ran the switched wire to the red output wire on the plug for the fuel pump relay. I need to know where the wire that triggers the relay comes from and where the power for the relay comes from. Also, with the switch off, the "check engine" light does not come on, but w/ the switch on, it does. The Haynes manual I have has no info on the fuel pump or relay wires. HEELLLPPP :cry :cry

 

Have you replaced the relay. It is located on the firewall to the right of the wiper motor.

 

Are you getting any codes? Certain codes tell the ECM to shut down the fuel injectors. Just a thought.

 

Blue, I did replace the relay (forgot to mention). Haven't checked for codes, but the light was not functioning until I got the pump working again. When it did work, it did not come on.

 

Check out this Tech Tip. It may help.
http://www.corvetteforum.cc/techtips...D=95&TopicID=2

 

I checked the link, but it is not what I'm looking for. I pulled the fuel pump to test it and checked all the wires back there. They all looked good. My car still runs w/ the switch. I just need to find out where the wire that triggers the relay is coming from. I'm thinking maybe the ignition. I am really tired right now, so I'm not going to mess with it today. Tomorrow that thing is coming apart until I find the culprit. :mad

 

Really strange that the car is not setting the SES light and a code 54.

ECM directly controls the fuel pump relay on my 89. It is feed from the Dark Green wire right from Term. A1 on the ecm. The black wire is ground on the relay. Actual power to run the pump comes from the Orange wire, and it's connected to the battery and also supplies the ECM.

When you turn the key on the Dark Green wire should be +12V for a few seconds. If it does not go to +12, then you have to trace the Dark Green back to the ecm and see what happened. If Dk Grn does have 12V, check the black wire for a good ground.

If both the Dk Grn and black are OK, next is to check the Orange wire that should be +12V all the time.

Have you tried hooking +12V to pin G (bottom row far left) on the ALDL connector? This back feeds the fuel pump through the second set of contacts on the pump relay and should be a red wire.

Good Luck

Pete

 

dtorc4;
It sounds like a fusable link over by the battery, but I need to go home and dig out my 85 wiring diagram. If I under stand just what you have said, you are not getting power to the fuel pump and also you do not get a "CHECK ENGINE" light on with just the key on unless you jump the fuel pump fuse. What I think is happening is that as you crank the engine oil pressure builds up and lets power from the fuel pump fuse to go back wards through the oil pressure fuel pump switch and the car starts. If I am correct and the 85 is like the 88 wiring diagram I have here at work(and I thinl it's close enough) you will need to check the connector over by the battery I thing 85 have two single wire connectors with fuseable link on them, you need to check the connectors being neer the battery they are subjected to acid from the battery and you know what that can do to good connectiong no to mension the problems to the wiring and connector. My guess is that you will find the problem there. Now if you find the link blown just let me know I will have to walk you through places to look were there could be a short that took the link out, but I realy think the problem is at the connector I have found that many times before.

David Fulcher

 

Thanks a ton David. I will check that tomorrow. I was looking for a fusible link, but I could only find the one that runs to the fan. And thank you for the wire color codes Pete. I hope I can get this knocked out tomorrow. :cheers:

 

Yes I have checked my 85 wiring diagram and there should be two fusable links coming off the smaller red wire off the battery cable(three if there is HD cooling) the one with the connector goes to the ECM fuel pump relay and a few other things this is the connector you would use to clear codes and the one you need to look of for your problems.

David Fulcher

 

Good news (sorta). I found my old Haynes manual, and it has the entire ECM wiring diagram. The revised Haynes do not have the ECM diagram. I can trace all 5 wires if need be, too. I broke down and went to the Shack for a multimeter. Since it is dark now, I will get on it first thing in the morning.

David - Some goofball who had the car before me rewired the fan and whatever else comes straight off the battery. I do have the aux fan in front, but it has never worked. Now I know why :smash: There are no fusible links left to be found. :mad Are those links just fuses or do they have a resistor or something as well? If they are just fuses, I will run the wires correctly w/ the proper fuse rating.