Ok here is the run down.

I cannot get the fuel pump to prime or come on at all. I've troubleshooted using the diagnostic box and still have had no luck get the pump to come on.

I ended up replacing the stock pump with the denso supra pump and still no luck.

I checked to make sure I was getting voltage to the fuel pump connector and it is reading very closely to what my pfc is display...11.7 volts, (I have the fuel pump rewired) My battery is going dead from constantly attempting to start, hence the low voltage atm.

I've replaced all my 30a and 40a fuses. Still no luck here.

My fuel pump relay is clicking like it should be.

Any chance my EGI Relay could be bad?...should I be getting voltage to the egi relay when my key power on? I wasn't getting any volts earlier when I was checking this.


Can't seem to diagnose this...could use some of you guys' help.

 

Check these things. 1. When someone is starting the car can you hear the pump clicking? Listen to it from the filler with the gas cap off. If you can then the problem isn't the pump. If you can't, however, then try this out:

1) You said that It's getting power to the connector (check the wires from the connector to the pump. make sure they're in tact).

2) If it's good there. then check the continuity on the fuel connector plug. (see page F-100 of the manual or pg. 288 in pdf)


If that's good then my guess is it's a grounding problem or one of the fuel components on pg297 or F-110 in the manual.

Get out the voltmeter and start checking.



p.s. did this just start out of the blue?

 

Which fuel pump relay? The green circuit relay also controls the fuel pump.

 

the green circuit relay is the one I was refering to...I did not check the fuel pump (speed) relay...but I did put a jumper in its place just for troubleshooting measures.

And yes this problem just kind of started out of no where...what about my EGI relay question though? Should I be seeing voltage when the key power is turned on?

My EGI Relay isnt clicking over/engaging with key power on...

 

Yes the fuel pump primes when the key is switched on.

 

I had the same problem over the summer. I am running a Microtech LT-8. After trobleshooting the whole system, I determined that the problem was in the computer itself. My choices were to send it back to Australia and be without the car for a month or so, or run a new wire and switch directly to the pump, from the battery. Since my battery was already in the bin, behind the drivers seat, it was an easy descision. One benefit was the increase of voltage to the pump. I had to go thru all of the maps and pull out 2-3 points because the AFR went from 12/1 down to low 9's. Downside is remembering to shut the pump off before you leave the car. It was several drained batteries before I was trained on this.

 

On the car I had this problem with, the circuit relay was not getting signal from the ecu. I traced the problem down to be somewhere in the body wiring harness between the ecu and relay. The price of a new body harness and the labor to install it was beyond my customer's budget so I ran a separate power wire from the ecu to the circuit relay. If I remember correctly it was a thin blue wire. I cut the original wire and sealed off the ends at the ecu.

 

My circuit relay and egi relay both seem to be functioning. I'm getting voltage to both, and both relays are engaging...would it be possible the relay is still getting no signal from the ECU?

The pump appearently pumped some gas for a slight second, because I got it to crank over for a second before it died on me...but I couldn't get the pump going again.

I remember I had to solder my resistor back together not to long ago and it may be possible the solder broke apart...not sure if this would affect anything though, I thought when jumping the f/p in the diagnostic box it bypassed the resistor anyway.

 

At the pump run a larger ground(10awg) from the fuel pump connector right to ground . Even if this isn't your problem it should be done. This circuit has a poor ground path. My friends car had me stumped with the same problem. It was the connector itself ontop of the fuel pump assembly. Check continuity between the top plug, to the fuel pump it self. I actually had to drill a hole and run another wire through the assembly for him. Obviously make sure its done right with some kind of "sealed connection". Good luck I know these things can be frustrating!

 

thanks i'll be sure to check that connector...i'll report back soon.