Need help!! Fuel pump wont turn on!!
- Thread starter SFLDragon
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if you worked in the engine compartment only, are you sure the power feed to the pump is hooked up to battery power?
what year is the car? late 92's (though i have seen a late 91) have the FP relay under the hood - pass side on the strut tower.
good luck.
what year is the car? late 92's (though i have seen a late 91) have the FP relay under the hood - pass side on the strut tower.
good luck.
This is the 3rd or 4th post I have replied to this month with people hiding their wiring and then having problems. You probably messed up the computer ground. People don't think of grounds as important, but without a good ground, you can have a megawatt of power and not be able to do anything with it.
1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.
2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery. It is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
4.) All the sensors have a common separate ground. This includes the TPS, ACT, EGE, BAP, & VSS
5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It is in the fuel injector wiring harness and comes out under the throttle body. It gets connected to a manifold or head bolt.
6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself.
7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.
8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.
See http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103#volt for help troubleshooting voltage drops across grounds
1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.
2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.
3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery. It is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
4.) All the sensors have a common separate ground. This includes the TPS, ACT, EGE, BAP, & VSS
5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It is in the fuel injector wiring harness and comes out under the throttle body. It gets connected to a manifold or head bolt.
6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself.
7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.
8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.
See http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103#volt for help troubleshooting voltage drops across grounds
yeah, it is an 18 guage (IIRC) fusible link off the starter-solenoid hot-lug. But Joe very well may be correct about the ground being the issue here(Raginstang or something like that had similar issues, IIRC). I did not think of the puter ground (which matter of fact, you and Joe helped me find, IIRC.TheUser said:
as being a likely culprit at first. makes sense though!)Similar threads
