Fuel issues

[silversho89]

I keep having a problem with my car. The fuel pump keeps kicking off for an unknown reason, usually when i put the clutch in while coming to a stop. Ive replaced the fuel pump and have swapped the ircm for a known good one. Theres is no fuel pressure at the rail and you dont here the fuel pump prime when you turn the key. It seems that when you start moving the car around, like flat towing or putting it on the trailer, it will start again.

Please help, this has been an ongoing problem for the last few months and im getting frustrated with it.

TIA,

Rob

 

[MADDOG11]

Try resetting the inertia switch locted in the trunk of on the pass side.

 

[dantheman68]

or the fuse...

to check the switch might not be enough... ive heard of on other cars the switch having bad contacts or just plain going bad... so just because its popped up doesnt neccicarily mean its not completeing the circut... also the IAC could have a hand in one of these things... although if thats bad the car wont idle at all...

 

[dstig1]

Not quite true. The typical IAC problem I have every few years is that the car dies when slowing to a stop from hiway speeds. The IAB is sticking and doesn't make the needed adjustment so the car dies. Idles fine otherwise. When this happens I disassemble it, hose it out with carb cleaner and am good for the next 3-5 yrs.

My point is that IAC problems are not always the same.

The other point is I doubt it is an IAC problem, but it certainly doesn't hurt to take it apart and clean it out good. Basically free to do with 30 min of time.

 

[ohfosho]

you are absolutely sure that it is caused by the fuel pump? the fuel pump is indeed working intermitantly?


the problem sounds like a CPS issue

 

[TYSHO]

to check the switch might not be enough... ive heard of on other cars the switch having bad contacts or just plain going bad... so just because its popped up doesnt neccicarily mean its not completeing the circut... also the IAC could have a hand in one of these things... although if thats bad the car wont idle at all...

To add to this, you can pull the wires from the switch and connect them together, bypassing the switch.

 

[projectSHO89]

Rob,

What year/engine?

If an 89, power to the IRCm for the fuel pump is suppled via a fuse link. There is also a resistor in there for the low-speed pump circuit (removed in later year models).

Steve

 

[Paul]

Try this, after an intermittant failure, open the hood and do a wiggle test or push the wires together at the group of harness connections mounted above the fan motor. one of these plug connectors is directly related to to the fuel pump power coming off the icrm. A wiggle test at this connection & the pump primed up.

 

[silversho89]

Rob,

What year/engine?

If an 89, power to the IRCm for the fuel pump is suppled via a fuse link. There is also a resistor in there for the low-speed pump circuit (removed in later year models).

Steve

Its on the 91.

you are absolutely sure that it is caused by the fuel pump? the fuel pump is indeed working intermitantly?


the problem sounds like a CPS issue

Im absolutely sure the fuel pump is kicking off and positve, now that the pump is replaced, that the fuel pump is NOT the culprit. Also, the cps was replaced about a year ago along with the cam sensor, both of which dont even have 10k on them.

Try this, after an intermittant failure, open the hood and do a wiggle test or push the wires together at the group of harness connections mounted above the fan motor. one of these plug connectors is directly related to to the fuel pump power coming off the icrm. A wiggle test at this connection & the pump primed up.

Have done this already also.

Rob