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by-passing the Fuel manager

Turbine Doc said:
I wouldn't bypass it, as you'll lose the WIF sensor, and the heater, better to add in a 10 micron before the lift pump, that way on engine filter will last longer
Click to expand...

thats not the problem I am having. it keeps losing its prime. I will tighten it back up and then after a day or 2 it will loosen back up and bleed down over night..... wont start the next morning.... does this twice a week and it is always the big round black lock ring.

is there a special tool I need to do this? I have been using a big ass pair of channel locks.

while I am asking.........

you got a list of what new items I need to add to my tool box?
 
Have you changed the filer ? it comes with a new o ring. I know walt sell the whole assbly. Not sure if anyone else does. The black ring,nut can be bought at the dealer although I would lean more towards a bad seal on the filter. It can be replaced but I wouldn't use anything less than a heated Racor which will cost alot more than a new factory setup which works just fine. Are you sure it's leaking from the ring ? They are also known to leak where the sensor goes on the side.
 
It sould not be "loosing" it's prime because you are post LP which is pressureized at that point. Hmmm wait you have a 94, no LP run till there's oil pressure.
 
Acesneights1 said:
Have you changed the filer ? it comes with a new o ring. I know walt sell the whole assbly. Not sure if anyone else does. The black ring,nut can be bought at the dealer although I would lean more towards a bad seal on the filter. It can be replaced but I wouldn't use anything less than a heated Racor which will cost alot more than a new factory setup which works just fine. Are you sure it's leaking from the ring ? They are also known to leak where the sensor goes on the side.
Click to expand...

Go here, you can buy an updated FTB version of that manager.

http://www.walkingjdesigns.com/
 
the O-ring was part of the filter....... the lock ring backs off. I have to retighten it every other day or so. it always starts after tightening the ring and cranking a few times like it is purging air from the system.

my LP runs key on engine off (looks like the opsu has been by-passed) and it works good because it shoots fuel out of the water drain when you crack it open. Looks like the FTB mod has been done to it aswell.
 
Two o'rings, the captive one on the new fuel filter and the not-removed old one stuck in the cap-ring, result in fuel leaks, as does a split plastic cap-ring, as do sensor and heater seals

- correct LP function:

- OBD1 LP runs during START, then with rpm signal and oil pressure permissive
- OBD2 LP runs in WTS for prime, also in START, then with rpm signal and oil pressure permissive
- both kill the LP if no rpm for fire hazard prevention
- both kill the LP if no oil pressure with rpm which prevents damage resulting from low or zero oil pressure
 
gmctd said:
Two o'rings, the captive one on the new fuel filter and the not-removed old one stuck in the cap-ring, result in fuel leaks, as does a split plastic cap-ring, as do sensor and heater seals

- correct LP function:

- OBD1 LP runs during START, then with rpm signal and oil pressure permissive
- OBD2 LP runs in WTS for prime, also in START, then with rpm signal and oil pressure permissive
- both kill the LP if no rpm for fire hazard prevention
- both kill the LP if no oil pressure with rpm which prevents damage resulting from low or zero oil pressure
Click to expand...

fixed the fuel filter. First morning that it has just fired right up since I bought it. plan on a relay for the LP.... going to leave it the way it is for now... the Original owner doesn't strike as the kind of guy to do things for no reason.

just fired right up .... no blue smoke........ guess what I thought was a leaky injector was just a plugged Fuel pump and then a bad seal after I changed it.

next fix will be the leak at the tank.
 
Already is a LP relay, thoughtfully provided by the engineers at GM - it's that large semi-round one up on the firewall, adjacent the LP fuse - controls the LP in START - have to be careful if rewiring it, as any applied voltage will energize the starter solenoid - I used 3amp diode or-gate configuration to get OBD1 LP in WTS, LP in START - also used schottky diodes, iirc, to reduce forward voltage drop
 
gmctd said:
Two o'rings, the captive one on the new fuel filter and the not-removed old one stuck in the cap-ring, result in fuel leaks, as does a split plastic cap-ring, as do sensor and heater seals

- correct LP function:

- OBD1 LP runs during START, then with rpm signal and oil pressure permissive
- OBD2 LP runs in WTS for prime, also in START, then with rpm signal and oil pressure permissive
- both kill the LP if no rpm for fire hazard prevention
- both kill the LP if no oil pressure with rpm which prevents damage resulting from low or zero oil pressure
Click to expand...

To add, the LP will run with just oil pressure, but its hard to have oil pressure without RPMs, however it happens post shutdown before pressure bleeds out of the OPS the LP will continue to run without IGN or RPMs.

OBD1 is all independent of the PCM, just START switch triggering the LP relay, or OPS sending power directly to the LP (no LP relay during operation).

OBD2 LP is run by the PCM at all times through the LP relay. But the LP will also be powered through the OPS. Its redundant during operation, but the OPS may run the LP post shutdown when PCM is off and oil pressure has not bled off.

So in a 94, as gmctd said, you could just send the OPS power output, spliced into the LP relay trigger wire there on the passenger firewall. Its a purple/white wire into the relay. And the diode to prevent power going back into the START switch.
 
Just did that mod today, I just used an automotive relay, cut grey wire on OPS harness and have the one from OPS trigger the relay (contact 85) and other side is to LP, contact 30 or 87, whichever way you want it to work.
 
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