Walbro 255 Install/Car Shut Off

[Joel Russo]

I ordered a Walbro 255, and Hotwire kit from TT, and installed it on my '87 GN over the weekend.  Installation went smooth, as I took my time, and I'm pretty anal...
I started the car this morning and it fired right up, fuel pressure went right up to 44lbs at the rail, and stayed there.  I check for leaks as I also replaced the fuel filter.  All was well, so I ventured out on the maiden voyage.  Car ran like a scalded dog as it always has.  I got a few miles from the house and realized I forgot my wallet.  Always nice to have when you get pulled over  
I shut it off in the driveway, got my wallet and came back out to the car.  Opened the hood to check fuel pressure again when I started the car.  Car fired up, then I noticed the gauge drop as the car started to stumble.  Fuel pressure dropped to 20lbs as the car shut off.  The first thing I did was check the 20 amp mini fuse that is on the Hotwire harness that mounts to the rear of the alternator.  Fuse was blown.  I replaced the fuse with another 20 amp, and the car still would not start.
I checked the FP and injector fuse on the fuseblock, and they were fine.  Ended up pushing the car into the garage and now I'm begging for help....
 

[Steve Wood]

If it were me, i would run a hot wire from the front of the car directly to the pump power in feed and see if the pump runs, does nothing, or gives you a big spark when you touch your test wire to the pump input

IF the pump runs and does not create heat or a big spark, then you could concentrate on the wiring before it.  If it does not operate correctly, then you have a problem with the pump or install.

Where did you get the pump and what is the number for it?

[PacecarTA]

when you replaced the hotwire fuse did you check to see if it blew again ?

sounds like a bad install
the fact that it ran means it was somewhat correct ..at least for a little bit

the blown fuse in the hotwire means you need to concentrate your trouble shooting efforts to the hot wire feed wire from alt to the hotwire relay at trunk or the pump wiring from that relay to the pump,

check the run of the hotwire from front of car to rear and look for a rub through or pinch through of the main feed wire
if not there you may need to drop the tank and take another  look at what you did



 

[Joel Russo]

This is what I have done so far...
 
I unplugged the hotwire and ran 12 volts to the pump via the factory plug.  The pump makes a humming noise, but I don't get any pressure at the rail.
 
I bought the pump and Hotwire kit from Turbo Tweak.  The Hotwire kit and pump came with Racetronix labeling..
 
After I replaced the hotwire fuse, it did not blow again, but then again the car would not start either..
 
I'll get under the car and check to make sure nothing pinched the Hotwire from the front to rear, then I guess I'll drop the tank?

[Steve Wood]

If the pump does not make pressure when wired directly, that should tell you something

[Just a Six?]

The pump makes a humming noise, but I don't get any pressure at the rail.
 
Rubber hose from pump to hangar blew off?? 

[Joel Russo]

If I confirm that the hotwire harness is not pinched or compromised, I'm going to drop the tank and remove the pump to make sure the hose did not blow off.
 
Would that cause the fuse to blow on the hotwire harness?
 
Any chance the factory relay went bad?

[Joel Russo]

The Hotwire harness is not pinched, nor is the lead from the relay to the tank.


I pulled out the pump and the short hose from the pump to the hangar was on.


    Nuthin' is ever easy...


Now what?

[Steve Wood]

As the pump made noise and nothing happened, it had to be the pump or the hose.....unles s someone clamped off a rubber hose between the  tank and the fuel rail which is pretty unlikely.

Looks like the pump must be dead.  You can drop it in the tank and run it on the ground to see if fuel comes out under pressure....in case there is any doubt.  IF not, contact Eric

[YGspider]

The Hotwire harness is not pinched, nor is the lead from the relay to the tank.


I pulled out the pump and the short hose from the pump to the hangar was on.


    Nuthin' is ever easy...


Now what?

[phil_long]

Dead pump? Seriously? That blows....A whole lot.  Explains why a LOT of guys go with the DW pump...Good luck getting the car back up and running.

[Steve Wood]

Saw a bad DW pump the other day.  Guy was telling me it could not be bad because it was new and it was guaranteed for three years!  It was dead.

Chinese is Chinese no matter what the guarantee so like all things, you take your chances.  At least, I think Walbro if it is not a counterfeit is made on this side of the world....

And you really need to replace the in tank harness with a heavier wired one when you go DW or Denso...

[Joel Russo]

Steve... Do you recommend I replace the in tank wiring?  This Walbro came with the wire that plugs into the pump and goes to the hangar.

[stratman]

when i bought my pump from racetronix they told me to make sure that i check the polarity of the pump because the positve and negative could be reversed.

[Steve Wood]

Steve... Do you recommend I replace the in tank wiring?  This Walbro came with the wire that plugs into the pump and goes to the hangar.

I would....these harnesses are really old and the ground side has always been weak

Racetronix sells an hd harnesses that replaces the bulkhead connector in the sending unit and runs the ground wire all the way to the connector so you have a direct ground path.  Be sure you tug gently on the wires to make sure they were well crimped in the bulkhead connector