OlrustysGhost

87 Vette, I am having a problem with the fuel Pressure. I just replaced the fuel relay, .. again. The 2 Second cycle is not working. when I first replaced the relay, "I have a fuel pressure gage hooked up", the pump activated and pressure came up to 38. It started fine ! problem fixed, or so I thought. let it run about 5 min, then shut it off. Now I am not getting any fuel at all, pump is not activating. when I let it crank for a little trying to start it, I get no pressure. The Fuse to the pump is good so I'm missing something. oh yea , I did clean the connector to the relay, it was cruddy. didn't help. I just would like to be able to drive the it without worrying about breaking down . any help would be greatly appreciated.

Joe C

need a little background history. 1) why did you replace the fuel pressure relay? 2) have you done any electrical work, especially with any ground wires in the engine compartment? 3) any significant engine work? 4) when you cleaned the relay's electrical connector, did you use dielectric grease?

pretty sure the 2-second fuel pressure thing is a function controlled by the ECM.

OlrustysGhost

1. replaced it when I first got the car. It was doing the same thing then . 2 yrs ago.
2. no electrical word done.
3. no engine work . changed plugs , distributor cap, rotor button , and coil thing in there. when getting fuel , the thing runs great. it will lay black marks about 50 to 60 feet when you nail it.
4. when I cleaned the connector, I pulled it apart one wire at a time. the connector comes apart pretty easy . I did not use grease putting it back together. I wanted a good connection. Grease would be later.
5. I do suspect a ground issue. with it The interior lights don't work and it seems that all those work from ground.

I did check this. the relay is sending the right voltage. to each wire. This was checked by meter to each one . That was with the old relay. I used battery post for ground .
the black/white wire from the relay is ground. I checked to battery from relay
is there a ground somewhere I need to look at or Test?

Joe C

do you have a factory service manual (FSM)? if not, get one. you will need electrical diagrams and schematics to trouble shoot this problem. as I said, the 2-second fuel pressure thing is an ECM function. if the ECM is not grounded, there's a chance that the circuitry providing the 2-second fuel pressure is in-op. if the ECM was powered without a ground, there is a really good chance the circuity was fried. if that is the case, you will need to replace the ECM. I don't have or have access to an 87 service manual, so i'm not sure where an 87's ECM is grounded. on my 85, it's grounded at the back side of the LH cylinder head. you need to start with the FSM. one question, since owning the car, did you ever have the 2-second fuel pressure thing?

OlrustysGhost

Haynes Manual. no diagram of the fuel system that I could find .
Yes the 2 second fuel pressure did work. I can't say if it worked all the time tho.
when I changed to a new one today , first thing I got 2 second pump action. car started right up. One time. all other efforts nada. no fuel pressure. no pump action
I will check the ground tomorrow. I hope someone has a diagram of it . I can't seem to find one.
this thing has to be simple I hope. Gonna be a nice day tomorrow here so I can spend some time on it.

Joe C

if you're planning on doing your own wrenchin' you need a FSM, haynes and chilton are fair generic backups, but nothing like having a year specific factory manual. good luck with the repairs -

OlrustysGhost

replaced the fuel relay , replaced the pump. They were not it.

Fixed It !
It was the connection in the tank. When I pulled the assembly out and replaced the pump, I didn't check anything . just a quick exchange . Put everything back together and nothing, no pump action. I had power to the connection at the tank. so that was good.
I took the assembly back out, and started checking continuity . I had nothing at the pump connection. when I checked the upper connection of the assembly, I found corrosion on the pins. Cleaned them up , checked continuity, it was good now. put everything back , turned the key, got the 2 second run on the pump , fired right up!

That is my story and I'm sticking to it.. My lesson? Always check connections .I could have saved a ton of time and energy doing this.
.

Joe C