geoduke

I've attached a wire to the + on my battery and run it straight back to the fuel pump + to manually get the pump to run. I can hear that the pump runs and verified that fuel is getting to the rail via the banjo bolt.

The pump behaves strangely though. It will run for 5-10 seconds with the jumper wire attached to the battery. During this time, fuel pressure increases to about 15 psi.

After 5-10 seconds, the fuel pump will stop running even though the wire is still attached directly to the + battery terminal. It will stop running for some period of time and then go back to its 5-10 second run time until quitting out again.

Does this sound like a bad pump? Why is it intermittently running like this? Just want to verify with someone on here before dropping the cash and time on installing a new pump. I think I should have something like 40 psi at the bolt??

scope103

At 15psi, it isn't even opening the Fuel Pressure Regulator, so you will never hit the spec fuel pressure (38-44psi with engine off; no point guessing about things like this http://web.archive.org/web/201501160...28fuelpump.pdf).

Unless you have a wonky connection to the power source (are you just twisting a piece of wire around something?), it sure sounds like a bad pump. It's pushing as hard as it can, and when it gets up to 15psi stalls out.

By the way, you don't have to crawl under the truck to do that test; the FP pin goes straight to the fuel pump.

Also, don't forget that the crush washers on the banjo bolts are ONE time use. You can only get them from the dealer (so far as I know), but they are cheaper than dirt. Don't risk a fuel leak.

geoduke

Thanks scope, just wanted to get confirmation from another person before pulling the existing pump.

I guess I'm lucky in that I can access the wiring to my fuel pump from the back seat as opposed to underneath the truck.

I have a few additional unused crush washers pertaining to this install laying around. You wouldn't happen to know the torque spec for that would you? I bought a 'Russell 640700 Fuel Pressure Take Off Banjo Bolt' from amazon (free shipping) and I'm planning on capping the end of it with a plug so I only have to use the crush washer I have laying around one time.

wallytoo

iTrader: (1)

the cold start injector/banjo fitting uses two crush washers, with the banjo fitting sandwiched between them.

scope103

The answers to All Questions are found in The Good Book: http://web.archive.org/web/201208130...68cylinder.pdf 25 ft-lbs. It's worth getting a 1/4" torque wrench just for these low-number torques. Like the valve cover bolts. No excuse not to have one: http://www.harborfreight.com/14-in-d...nch-61277.html

Yes, all of the crush washers are in pairs surrounding a banjo.

geoduke

I knew archive.org was good for listening to old grateful dead shows but had no idea it had FSMs as well!!