Fuel Issue! Need it resolved before DGRR! Help!

[FerociousP]

I have a '90 vert with a full T2 swap. I have a Rtek 2.0, 550pri, 750sec and a FD fuel pump. The pump was brand new last year from Denso with a brand new Denso strainer (FC OE cube type). The tank is perfectly clean on the inside, no sludge at all. It is so clean it looks like new sheet metal on the bottom. I've put about 5k miles on the car with the pump in the last year.

Last week I drove it to work and it was running great. On the way home, only a mile from work, the car shut off and wouldn't restart. I waited about 30 seconds and the car started, and died. I got out and checked my inline gauge. 0psi. I couldn't crank it and look at the gauge so I left it and came back later. When I got back to the car an hour later, it fired right up and I drove it 10 miles home with no issues! WTF! This saturday I drove it 20 miles with no issues and shut it off. A few hours later I started it again to go back home. Again, one mile later it died. Similar symptoms, but I noticed that the fuel gauge would start dropping right before it died. Sometimes it wouldn't die completely and the car would stay running, and the fuel gauge would follow form by rising back to normal level or dropping. This shouldn't happen correct? Has anyone experienced this before?

The fuel resistor box (especially the heatsink fins) behind the pass headlight gets too hot to touch when the car is running. I assume by the heatsink it is supposed to get hot. but this hot? Can anyone check their running car real fast?

I can get a pump within an hour, but I don't want to spend the $$ if I don't have to. I have until Wed night to get this sorted out! Give me some ideas. I'd rather not direct wire unless I absolutely have too.

[ZGN]

the resistor pack on the FD does not get that hot, should be the same for the FC. You could jumper it to bypass the resistor and if that was your problem your pump should have full voltage to the pump. May also be the relay or bad harness or ground.
You can carefully strip off some insulation from the + on the fuel pump and see if it getting the proper voltage with a multimeter.

[FerociousP]

I measured the resistor part of the pack and got 1.3 ohms, which is slightly out of spec per the FSM (.9 limit i think ) and would cause it to get hotter, correct? I was getting 6-7 volts at idle when it was running. With the yellow pin jumpered and the car off, I was getting full voltage but occasionally everything would just stop. I'll check my grounds (TTT) tonight.

the pump measured 1.1-1.2 ohms at the connector. Is that typical? I've never measured one before.

[My5ABaby]

More resistance would make it run hotter. If it's just randomly stopping I would suspect a ground.

[FC Zach]

That's what it sounds like to me. I would check the grounds around the access plate and tank.

[diabolical1]

i agree that it could be a bad ground.

[FerociousP]

Possibly had a bad ground connection IN the hanger assembly. wiggling the harness gave me some fluctuating resistance so I depinned the connectors and tightened up the pins. Solid ground connection out of the tank, and checking the rear harness ground wire to the negative battery terminal showed a good connection. This makes the most sense as it is the only common connection between the pump and the fuel gauge sender.

I'm getting around 7-8 volts at idle and around 10.5 with the resistor jumpered. Its running ok now, but it always starts and runs for a while.

[FerociousP]

Almost 700 miles later through Deals Gap 4 times and up the Cherahola Skyway... no issues. Grounds Grounds Grounds people! Ground wire connection through the fuel hanger bulkhead was the issue. Fuel gauge is more accurate too. Bonus!