Fuel Pump and Controller

[QShip]

Here's a recap of what happened:

I was driving my 91 Q w/ 114k miles the other night and it cut off on me. The guides have been done, transmission replaced and it has been converted from active to conventional by Sopdadope.

Anyway, I was cruising the highway to get some gas and I felt the Q slow down and the rpms drop. I pulled to the side of the road and waited a few minutes. I checked the oil and coolant reservoir, both looked okay.

I started the car and pushed on the gas pedal to take her home but she cut off again. A message flashed saying the Battery Charge level is low. After that, I had triple AAA tow her home.

Checked the ecu and received code 55. Which means no malfunction.

I checked the fuel pump by disconnecting the line at the top of the fuel filter and had my wife turn the key. No fuel came out. I then checked the resistance of the fuel pump and measured over 2 ohm of resistance. I believe the manual said anything over .5 ohm means the fuel pump is shot.

Also, the controller measures 7.57 - 11.59 volts from the junction between the fuel pump and the controller. I measured this while the key was in the 'ON' position.

Would someone verify if that is correct?

[Q45tech]

Unplug the white molex connector to fuel pump controller,Take a wire with 2 alligator clips and ground the lead from the pump negative terminal [in connector]. The pump [even most defective ones] should begin to run if it can.

The above works 9 out of 10 times when they get hauled in on a flat bed [works long enough for us to drive the car into the shop].

Of course you check the fuel pump fuse and relay. Don't over diagnose or test...........as the pump and the controller are usually the culprit.

When you replace the pump [due to age/miles], you then make sure the NEW pump runs and has not taken out the controller while everything is apart and controller is easy to get to!

We keep spare controllers around to substitute if the new pump doesn't start [without the jumper].

[QShip]

Of course you check the fuel pump fuse and relay. Don't over diagnose or test...........as the pump and the controller are usually the culprit.

I have checked the fuel pump fuse and that is ok. 1qckser told me to check the relay, but I don't know what and/or where it is. I'm sure I've seen it, I just don't know what it looks like.

[Q45tech]

Never seen a Q fuel pump relay fail in 7 years [but there is always a first time]. Do you get +12 on the pump input when the key is first turned if so the relay is working.

A gain follow my advice to the letter to avoid wasting time diagnosising some part which new fails.

We see at least 100 pump failures a year [so common we keep 2 in stock along with 2 controllers] and no relays.