ok, my brothers 87 GTA has been taking up precious garage space here at my house for over a year now, and it's because the fuel pump wont turn on,

i went through some similar issues with my car, from dropping my 87 IROC's fuel tank, pump, lines, etc, and getting mine working again... and more recently replacing the computer (ECM) when it blew, causing my pump to stop working

---with my brothers car, we have dropped hte tank, replaced the pump with a new one, and checked the fuel relay (on the firewall drivers side) etc...

my question is, what else could this possibly be.. the pump works, we have hooked it up to a 12 volt batt. and it runs, when we hook it up to the harness connector above the rear axel, it gets no impulse.. a test light confirms that there is electircal impulse there at the harness... how can we furthur diagnose this, fix this, or what else could it be,....

is there a FUSE someplace? there has to be? anybody know where? .. when we try to start the car.. the fuel pump relay box makes a click , but the pump makes no noise.. what does this mean???

-any help would be appreciated... as i am trying to get his car out of hte garage and mine inthere so i can begin the massive overhaul on the bodywork and paint...

 

There are 2 fuses for the fuel pump one in the fuse box, and one under the hood this one is also the ECM fuse, an easy way to tell if it is blown is when you turn on the key the ses light will not come on.

There is a test circuit on the aldl connector, run a wire from term G on the aldl to the battery conn in the fuse box if this dosen't start the pump then your f/p relay may be bad.

 

Oil pressure switch could also be no good. No oil pressure no fuel pump. $15 dollar part. It should be threaded above the oil filter.

 

i have the same probkem on my iroc...i go to turn the car on and the instrument panel lights up perfect! but the car wont start? the starter wont even move! so i was messing around with it and i got the starter to turn but the car wont turn on....i here the clicking under the hood and the pump running but then it turns off? anybody know whats going on? thanks!

 

When you turn the key on the pump will run and then shut down when the correct fuel pressure is reached. being your starter is working now, pump is runing, I would suspect your ignition module has gone bad. Check for spark at the plugs. An easy "no doubt" check is hook a timing light up and see if it works. Keeps the voltage out of your fingers!

 

ok well the only way i can get the starter to crank is if i kinda hotwire the car which i dont like doin....so what i wanna do is fix it right you know what i mean? so you said the ignition module? because when i turn the key everything seems right but the starter wont crank at all! any idea now? please help me!! i bought the car with this problem and i got it cheap thinking i could fix it but now im stuck! its a real nice car its a convertible!!!! please help me! thank you!!!

 

2BADCAMS I would be checking the VATS system. The resistor in the key could be wearing out. My Z does the same thing but all I do is remove the key, put it back in and it will start. Sometimes it starts right up first turn and some times it takes a few R&R's of the key. I will permanently fix it down the road.

 

ok, sorry i havent gotten to write back

i've worked on the car for the past 4 nights for a few hours each

i replaced the fuel pump switch (under the distributer) and checked the fuel pump fuse near the battery - its good..

checked the realy again, for VOLTS 12.28 and at the harness it was 10.74..

replaced the oil pressure switch and checked alot of the wires in the engine bay..

---since i wasnt getting a good # out back,a nd since the test light was very very dim when reading the power circuit at the fuel pump harness above the rear end, i knew there had to be a bad ground..

read the shop manual, and found that the ground for te pump is right under the right rear seat (drivers side rear seat) so i tookt hat out to find the screw holding hte ground wire to be almost off, and the ground definately not getting a good contact at all

redid all that,a dn heard the pump turn on, did it a few more times, checked for pressure at the fuel rail,a nd cranked the motor over..

the car runs

just very choppy at first, and then smoothed out, - i guess i cant complain that its choppy after not running in over 19 months

thanks for the advice fellas, --i hate it when ground wires get loose... but im glad it was as simple as that, and nothing more expensive liek an ECm again