rxtasy3

iTrader: (2)

got a friend that has an 85 se. it stopped running on him while driving it. he called saying it would start and run, but then die, and i could hear it over the phone. i had an idea what was going on so i headed his way. well, what i thought was right. when u turn the key, pump runs and it starts, but as soon as u release the key, the pump stops. at this time it was too late to properly diagnose since it was getting bout time for me to go to work, so i ran a wire from a switched source to get him home. searching hasn't really revealed a positive answer as this particular problem doesn't seem to have come up. one other thing that was notice, that alt belt had also broken and we couldn't see anything that might have been affected that might have caused this problem. i've also looked thru the online service manual from the sig link of rx7doctor. if i can't figure it out, i'll just do what i know works so any ideas would be appreciated.

gerald m

Is it possible that the start position on the key switch over rides the fuel pump relay ,? then when the key returns to run position the pump relay dosen't respond because of a broken circuit between switch and relay ?? Just a thought I really don't know what safety or roll over controls they have

trochoid

iTrader: (6)

The SE fuel pump runs under one of 2 conditions. The key is in the start position or the maf door is open. Fault can lie in the ignition switch, the relay or the maf.

2GSLSE

iTrader: (6)

Check the trailing ignition I think if it fails or the wire comes off the coil the fuel pump circuit will open and shut the pump down.

Siraniko

iTrader: (13)

just connect a 12-V and a ground via the 2-wire pigtail behind the driver side storage bin. then work your way back.

j9fd3s

iTrader: (3)

three sir! nobody expects the trailing ignition!

rxtasy3

iTrader: (2)

thanx guys. as soon as i get a chance to look at the car again, i'll check all these things out and let u all know what i find.

wacky, i found a switched 12v source to connect to that connector, i think it was a blue wire, to get it running so he could get it home. but not sure i know what u mean by working my way back.

Siraniko

iTrader: (13)

Mike,
The jerry rigged-wire will tell you right out the bat if the pump is good without wasting any time. If the pump doesnt run without it, inspect the relay above the brake pedal (use a test light).

My apologies if my prior post is not clear. When I draw a diagram, it starts from left to right, right being the load or the pump. When I say back, trace the 12-V back to the relay and vice versa.

rxtasy3

iTrader: (2)

o yeah, i knew the pump was good cause it would work during starting, just stop upon releasing the key. from what i've read in the repair manual, the pump relay on the se is under the plate in the pass floor board. i wasn't sure that's what u meant, i've always traced wires by following it thru the harness. didn't realize u meant by powering it and finding it with a test light.

Siraniko

iTrader: (13)

the fuel pump relay on 84-85 is above the brake pedal. there is a 4-wire pigtail, IIRC, there is a blue/?stripe wire. relay can fail also due to age so u se a test light to see if you have juice on the above wires. I can dig and tell you the exact relay/color code. I collect them for fun.

LongDuck

There's a simpler way to get the fuel pump to run all the time the key is in RUN, or START, and that's the green 2-lead 'Fuel Injector Test Bung' next to the Air Filter box on an SE.

If you make a short length of wire with 2 crimp connectors on it to shunt across this connector, it sends the same signal to the computer that the AFM door is open, i.e., air is coming in and the fuel pump should be running.

With the age of many of our cars, it's not uncommon to find mechanics that have jury-rigged something to make the car work, simply because they don't know the specifics of the design, and just find a field expedient way to get it running. Anytime you see wire splices and connections made that clearly don't belong, that should raise red flags.

Just trying to point you to some of the unconventional things that could also be at fault.

The Trailing Ignition lead is to trigger the EFI, so the fuel pump would be running under all conditions that a trailing trigger would occur (as the dizzy would be spinning, and the engine would be sucking air). Check this by moving the trailing trigger (white wire with crimp connector) to the Leading Ignition coil, and if the car runs fine - and it should, as the leading and trailing points are not that far off to prevent the engine from running - then you may have a problem with the trailing coil, the distributor cap trailing connections, the trailing coil ignition wiring, or the Trailing Ignitor (on the side of the dizzy).

These are all things to look for which would be indicative of the IGNITION circuit being part of the triggering problem, and not the fuel pump, itself. You've already identified that the fuel pump works fine. HTH,

Whisper

On the FI cars (GSL-SE) the relay is next to the ECU, under the passenger footplate.

rxtasy3

iTrader: (2)

yes longduck, i saw that about the jumper when i was looking thru the service manual from the foxed.ca website.