Fuel pump not priming...
Fuel pump not priming... Since I moved my battery to the rear I have had issues with it not starting easily, like a ground problem and I get the clickety starter sound. I already replaced a fuel pump relay this year when the fuel pump stopped priming and that fixed the problem. I know its related to the battery relocation issue, Im going to be putting the battery back in the stock location as soon as I fix this issue. Now Im getting no sound from the fuel pump when I turn the key on and it wont start. Bought TWO new relays, I installed the first one and didnt change anything so I got another to be sure, and nothing. I ran a testwire from the battery to the fuel pump 'primer' wire next to the PCM and the fuel pump runs then, so the pump is good. What else am I missing here, checked the Haynes manual and it just says verify the relay is good, then recomends replacing the pump if its bad. Are there any other fuses involved here? Haynes says there is a #8 fuel pump fuse in the fuse block (not for a 97 though) and it doesnt say 'which' fuse block so I checked both underhood and in the driver door access and all fuses are good. Im stumped, not sure what to do next, any ideas?
key on.. jump the pink wire to the green w/white wire on the fuel pump relay connection. if the pump turns on, then it's not getting a signal from the pcm.
the pink wire should have 12 volts with ignition on
test your black to ground continuity ( you should get a beep letting you know the ground is good)
the pink wire should have 12 volts with ignition on
test your black to ground continuity ( you should get a beep letting you know the ground is good)
I don't have a pink wire at the fuel pump relay connection. Have: red, orange, black/white, green/white and grey. Tried jumping the orange to green/white with key on, nothing from fuel pump. Also tried red to green/white, also nothing. I have 12v at orange wire to ground. I have 6v from black to ground w/key off. Is that normal?
Launching!
Joined: Aug 2010
Posts: 234
Likes: 0
From: Cincinnati, Ohio
the gray wire goes to the pump. your black/white is ground. Red is bypass for prime connector. Green/white is signal from pcm. Orange is your constant 12volts. I am also not getting signal from the pcm on mine. Ill keep you updated
did you do the continuity test from black wire to ground (so stick a probe in the black wire and touch a ground (like bolt on bottom of dash that all the grounds go to) and you should here a beep. Do this first, if you don't have a good ground, that is the first problem to solve.
Next probe for 12v, on the harness to see what is bringing the power to it. So if you have a good ground and you have 12v, then jumping your 12v source to the green/white wire will absolutely turn your pump on.
try that and let us know.
Next probe for 12v, on the harness to see what is bringing the power to it. So if you have a good ground and you have 12v, then jumping your 12v source to the green/white wire will absolutely turn your pump on.
try that and let us know.
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Launching!
Joined: Aug 2010
Posts: 234
Likes: 0
From: Cincinnati, Ohio
96-97 are different than 94. I just swapped my 94 lt1 into a 96. Jump the orange to the grey and pump will come on if it works. The problem you would have would be the green/white wire, that is the fuel pump relay signal wire from the pcm.
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"Since I moved my battery to the rear I have had issues with it not starting easily, like a ground problem and I get the clickety starter sound."
This sounds like a starter problem, how did you jump to the fuel pump from this? Does the engine crank? If not: My guess is your not getting enough current to the starter. How did you wire the starter and ground?
Al 95 Z28
This sounds like a starter problem, how did you jump to the fuel pump from this? Does the engine crank? If not: My guess is your not getting enough current to the starter. How did you wire the starter and ground?
Al 95 Z28
did you do the continuity test from black wire to ground (so stick a probe in the black wire and touch a ground (like bolt on bottom of dash that all the grounds go to) and you should here a beep. Do this first, if you don't have a good ground, that is the first problem to solve.
Next probe for 12v, on the harness to see what is bringing the power to it. So if you have a good ground and you have 12v, then jumping your 12v source to the green/white wire will absolutely turn your pump on.
try that and let us know.
Next probe for 12v, on the harness to see what is bringing the power to it. So if you have a good ground and you have 12v, then jumping your 12v source to the green/white wire will absolutely turn your pump on.
try that and let us know.
Ok, my orange wire is my 12v source, when I touch the orange wire to the grey wire my fuel pump runs, with key on, engine off. For the ground test, maybe this a dumb question, but what should I hear a beep from, the car or a voltmeter? I tried grounding the black/white wire to the bolt at bottom of dash with a piece of wire and with the voltmeter and I dont get a beep any where. Altough, I've never heard my voltmeter beep before. As you can tell Im no electrical engineer, lol. Is this a problem with my PCM or a ground issue?
Big Al, its not a starter problem, I just mentioned that because ever since I relocated my battery to the rear I get occassional clickety clack from the starter, but the car does then turn over and start. Ever since moving the battery I have had problems with the fuel pump relay going out every month or so. Like I said, I am so done with this battery in the back, it has been nothing but a headache since I moved it there. I never had ANY of these problems when it was up front, and car would always start immediately with no issues.
Thanks so much for everyones advise
your multimeter has a continuity setting. something like this. 
put it on this setting and then touch the ground from the harness to another ground. This will tell you if your ground is good. but since you were able to get it to prime, I suspect your ground is fine. It sounds like it's coming from your PCM somewhere.
put it on this setting and then touch the ground from the harness to another ground. This will tell you if your ground is good. but since you were able to get it to prime, I suspect your ground is fine. It sounds like it's coming from your PCM somewhere.
Ok, I figured you meant a beep from the meter. I set it on the speaker symbol and I get a beep from the grey to ground bolt and beep from black/white to ground bolt. Does this likely mean my PCM is f'd up and has to be replaced or can is there anyway to check it? I so wish I never put my battery in the back, ugggghhh.
no i don't think your pcm is screwed yet. do check the pcm fuse though. if anything else is working, than this should work too. Check your grounds on the block and block to frame too that they are tight.
the next thing to check is on the passenger side in the c200-c210-c220 connectors. i forget which one has the signal coming in from the pcm, see if you have signal coming. check shbox site for harness connectors to see which one it is.
the next thing to check is on the passenger side in the c200-c210-c220 connectors. i forget which one has the signal coming in from the pcm, see if you have signal coming. check shbox site for harness connectors to see which one it is.
I had issues like your symptoms. I pin pointed it to grounds from the starter to the block to the chassis. My question is what guage wire was used for power to the trunk and what gauge for the grounds? I was using the wrong gauge (6ga.and4) I then used 2/0 guage and problem solved now its cranks faster and fuel pump gets more power.
One more thing alot of 2/0 is usally not prefabbed with connentors already so you have to be sure the connectors are crimped very well or the connection will be worthless. I'm sure all this stuff you already knew though just throughing out all aspects.
no i don't think your pcm is screwed yet. do check the pcm fuse though. if anything else is working, than this should work too. Check your grounds on the block and block to frame too that they are tight.
the next thing to check is on the passenger side in the c200-c210-c220 connectors. i forget which one has the signal coming in from the pcm, see if you have signal coming. check shbox site for harness connectors to see which one it is.
the next thing to check is on the passenger side in the c200-c210-c220 connectors. i forget which one has the signal coming in from the pcm, see if you have signal coming. check shbox site for harness connectors to see which one it is.
http://shbox.com/1/harness_connector_faces.htm
Under the C220 tab I see this for 97:
J - Dk Green/White - Fuel pump relay control
If you can help me through this and get it running again I will seriously paypal you $50, thanks for your help so far.
Thanks for the advice, Im not really having problems with the starter at this time, just the fuel pump not coming on. Im going back to the battery up front once this problem is solved, Ive had it with the battery in the back.
Last edited by GREGG 97Z; Sep 11, 2011 at 05:30 PM.
I too was having the same issue with the pump! My starter would give a clicking sound as well but turn over just no fuel pump power. And it was solved with grounds!Good luck hope you get it going.
So, I went out, pulled the kick panel, figured out which connector it was from the diagram. I was about to check the voltage from each connector then I noticed that further up in the harness that the green/white J wire was BROKEN. I was soooo happy, I knew that had to be it. Crimped it back together, plugged it back in and there was that wonderful fuel pump sound again
Car started right up after that. I realized now what happened, last weekend I was removing wiring for my manual fan switch and was pulling an old wire through the access plug behind the pcm, the wire ran from there up to a switch I had in the dash area. It didnt come out real easily, it got hung up, like an idiot I didnt take apart that kick panel to see where it was stuck. Gave it a little tug and it came loose. That little tug was what must have broke the green/white fuel pump relay wire from the PCM. Later that day I tried starting it and ran into this problem. I've been trying to fix this for a week now, I had the biggest smile when I found that wire was broken!
Thanks man, I never would have found that broken wire without your help.