fuel pump control unit

[hannibal]

A friend purchased a 95 Q this week. i went with him and drove the car. It ran perfectly (no sputtering or stalling). After a 30min drive, the Q started hesitating 2 miles from his house. We pulled the car over, turned it off, and began looking for the problem. Didnt see anything obvious, so we decided to head home. The car cranked but wouldnt start. It would actually hold a low (100-200rpm) idle for a few seconds, then die.

It was towed to a shop who said the fuel pump was bad. They wanted $750 to replace, so he decided to tow it back home, and we replaced tthe pump yesterday.However the car still wont start.

I think the problem maybe the control unit. I heard the old pump hum when the key is turned to ON.I heard it the night the car stopped and yesterday just before we replaced it. However, we pulled the inlet hose from the fuel filter, and no gas came out when the car was cranked.

After installing the new pump, I tried to do the FPCU bypass trick. Looking at the connector side of the white pug, I connected the bottom left female pin to ground (the raw metal brace next to the gas tank). The pump refused to hum in the ON position. I used a piece of old headphone wire (thats all we had) to ground the FPCU. Even if this wire was too thin, it should worked for a second before burning out.

EDIT: Found a pic. THis is exactly how I did it, yet the pump would not come on.

I'm not sure if this means the FPCU is bad or what. I'm heading over to work on the car this afternoon and just need some advice.

Ive read tangalora's write-up (and many other threads), but I'm not sure if I'm bypassing the FPCU correctly. I have not checked the relay, which I plan to do today...

[goody90q45]

Here's a pic of which pin to ground. The FPCU that it was unplugged from can be seen in the background, mounted under the parcel deck. You should be running a wire to ground the same size as the ones going to the connector.

By bypassing the FPCU the pump should run on high speed only and the car should start. If you have no fuel pressure at the rail you either have a bad pump or relay (?).

You might get a hold of Drew (in Atlanta) for a known good pump and FPCU. He's a member/seller in the Infiniti Classifieds forum. Good luck.