Engine/Transmission (1998.5 - 2002) Lift Pump (FASS) won't run unless...

[TORQUE THIS]

If I run a direct line to the battery, it will run fine. Plugged back into the harness it won't run.

I tried a different relay in the FASS harness and still won't work.

When you turn the key or bump the starter, all I get is 3 quick little pulses out of the FASS.

Any Ideas???

 

[Batman]

Hey Mark,



double-check your connections at the relay. Don't assume they are all good.

I've installed 2 FASS systems, both had one connection that wouldn't seat completely. If this doesn't help, check that you don't have any condensation in the motor contacts.

HTH

G

 

[TORQUE THIS]

Opened up the motor and cleaned it all up, was pretty clean. Cleaned the brushes. Like I said the motor runs and pumps just fine direct to the battery.

The harness is also good, connections are all good / clean.


The thing I can't figure out is when you first turn the key on, I would always hear the pump cycle for a quick second. Nothing now. Bump the starter and the pump cycles 3 times quick. I'm wondering if there is an issue with the ECM...

 

[OPoole]

Is this a new FASS that your just installing? When you get the 3 pulses cut off the key for a few mins and try again should run for a 20sec? Here lately i have been selling and installing the FASS pumps i made a harness to run the pump till all air is out of the system. Then plug back in the lift pump harness takes out all the bumping of starter hope this helps.

 

[OPoole]

Sorry i took to long to post i see it a pump you have ran.

 

[TORQUE THIS]

After the 3 pulses, I have turned the key off and waited, remembered reading that somewhere. Still no go...

It's about 2 years old and I have been having fuel pressure issues. Thought it was a filter, changed it, and that's when I discovered the pump not running.

 

[TORQUE THIS]

Replaced the ECM, problem solved!

 

[PRout]

maybe you can save some bucks and put the old ecm back in and wire the fass relay to run off the power window circuit. . just a thought

 

[mhenon]

Did you just replace it or somehow figure out it was the problem? I'm wondering how many LP's have been replace as being "bad" when it was really the ECM? Especially, those guy's with multiple LP failures.

I've had a few occurences where my LP didn't cycle on when the starter was bumped. This is the first I've heard of the ECM being the cause.

Think I'll hook the LP up to the battery via a relay.

Mike