For the first time yesterday I finally was able to drive my Fiero on the road - insurance and all. It was going great for a while up until the point I smelled something hot, stopped at the side of the road and turned the engine off to check it out. Nothing was wrong, but now the car wouldn't start. I tried pop-starting it a few times, but I noticed the lack of fuel pump priming and delivery and had to get it towed home. I checked the fuses and did a cursory inspection of the wiring and it all looks to be good, but still the fuel pump doesn't run. I had also replaced the fuel pump after getting my '84 Fiero 8 months ago. The factory manual doesn't have much on the wiring situation or troubleshooting that I could find, so any suggestions or advice would be much appreciated.
[This message has been edited by 842m4SE (edited 05-11-2021).]
I would check the fuel pump relay and the oil pressure sender both of which are in the current path of the fuel pump. You might first check the connector to see if there is power feeding through. What brand of fuel pump did you use for the replacement?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
you said you did work.. perhaps check your plug and cable? they run by that CAT and are prone to melting if routed incorrectly .
I have, all looks to be well - no melting, cuts, or anything weird on the shroud or visible wires. Dis and reconnected the plug leading to the fuel pump a few times and it is reading ~8 volts.
id say jump 12v to the pump and see if it kicks. You should be able to read the voltage to of the fuel pump directly on the ALDL connector next to the lighter on/in the center console. Im not sure of 90% of things on 84s but you should be able to jump 12 volt to it there. its a Tan/White wire top row all the way on the drivers side. 8v seems too low could be a bad relay.
if not its not uncommon for a tank to have rust you did not see and for it to kill a new fuel pump. Im starting to think you need to drop the tank and look.
[This message has been edited by skywurz (edited 05-12-2021).]
id say jump 12v to the pump and see if it kicks. You should be able to read the voltage to of the fuel pump directly on the ALDL connector next to the lighter on/in the center console. Im not sure of 90% of things on 84s but you should be able to jump 12 volt to it there. its a Tan/White wire top row all the way on the drivers side. 8v seems too low could be a bad relay.
if not its not uncommon for a tank to have rust you did not see and for it to kill a new fuel pump. Im starting to think you need to drop the tank and look.
Replaced the relay today and same thing happened - nothing at all from the fuel pump. Jumping it did make a sound, each time they connected it made a short tap or clunking sound, but nothing else even when connected. What is it supposed to do?
Apply power directly to the fuel pump connector using clip leads. If you then have no fuel pressure, you purchased a defective pump . Ebay is full of AC Delco counterfeit pumps. Also today AC Delco stuffs just about any product that they can find in their boxes That's why I now use only Bosch Fuel pumps that are made in their own factory.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
For fuel pump testing purposes, jump 12v from the cigarette lighter to the ALDL fuel pump terminal.
Appreciate the image, did that again today and all it's doing is clunking when they connect, and not humming or doing anything while they are connected. Cigarette lighter is reading 12 volts so not looking too good for the fuel pump.
[This message has been edited by 842m4SE (edited 05-13-2021).]
Apply power directly to the fuel pump connector using clip leads. If you then have no fuel pressure, you purchased a defective pump . Ebay is full of AC Delco counterfeit pumps. Also today AC Delco stuffs just about any product that they can find in their boxes That's why I now use only Bosch Fuel pumps that are made in their own factory.
Unfortunately it's just clunking when I first put the leads on, then nothing. The fuel pump "Precision fuel pumps" actually came with the car, the previous owner ordered a couple of parts but never got to fixing.
Reminds me of the ignition module that came with my new distributor. Literally failed within a week. Swapped back in the Delco one that was 5+ years old and was in the previous distributor.
Unfortunately it's just clunking when I first put the leads on, then nothing. The fuel pump "Precision fuel pumps" actually came with the car, the previous owner ordered a couple of parts but never got to fixing.
Just for the record, I used a Precision fuel pump. It lasted about a week. I replaced it with a Delphi. Seems to be good to go so far.
