Clete

Working on a 2002 truck that quit. No restart, no CEL's. My first thoughts were the lift pump.

The lift pump will build about 15psi, but as soon as it shuts off it drops to zero

Also if you let the pressure build up to 15psi and start the cranking it will go to zero.

There was a bunch of air in the system, I checked from the lift pump back to the tank looking for a cracked fuel line. I soaped it down and remove the supply line at the lift pump and applied some air looking for bubbles. The line looks good all the way to the pick up.

So I plumbed a line from the inlet side of the Lift pump to a 5 gal fuel tank of fuel and the lift pump wopuld not pick it up unless the tank was higher than the lift pump, but the truck still did not start and the fuel pressure still goes to zero when cranking.

Once I got the fuel can above the pump the truck one cylinder statrted to fire and i got a little smoke but still no start.

My question is there anything else besides the lift pump that could cause a pressure loss like that? Any thing in the injector pump? Also i have no leaks forward of the pump.

Thanks
Clete

KLockliear

There is a check valve in the return banjo on the VP44 that can cause hard starting. It's about an $80 part from Bosch. If the truck has over 100k or is on it's 2nd (or more) VP44 pump, replace it.

Clete

Don't know the history of the truck or if its had the IP replaced. May end up being a combo.

Shouldn't the lift pump pick up the fuel out of the fuel can?

george7941

A functioning lift pump would pick up the fuel unless it was deadheaded, i.e. facing a lot of restriction on the outlet side

Clete

Stuck an Airtex lift pump on today, this is not what I wanted to use but the person that owns the truck is out of town and needed it quick.

Anyway the thing filled the bowl immediatly from the can and the tank, so i put the cap on the fuel bowl and it built 20psi and held 10psi with the switch off.

Bled the lines and the truck fired right up, run great for about 30 minutes at the shop . Took it for a road test and it got about 5 miles and quit, I had the fuel pressure guage hooked up the whole time and it went to zero.

Got it back to the shop and the pump will not pull any fuel from the tank or the can, but it is running. ***


Any ideas.

I got a FASS pump coming now.

nickg

any chance its outta fuel? apparently the fuel senders are famous for inaccurate readings, also I've seen a fuel tank (GM metal) collapse near 60% from a faulty fuel cap, I would not have believed it if I had not seen it.

crap.... Just re-read your post sounds like the new pump did break again esp since you said the pump would run but NOT suck from the tank or from the can.

I see that Airdog has a sale on for 499$ check the banner at the top of the page

Clete

Ya tank is 3/4 full, I used my fluid evacuator and hooked on to the top of the sending unit to make sure it was pulling fuel. It pulled fuel and continued with a constant flow.

I guess its my crappy luck that the pump went out. I thought that it may have injested a bunch of crap, but the pump has a screen on the inlet side and it is clean.

Anybody got any history on the Airtex pump as far as reliability.

Also I have heard people say that the truck will run with a lift pump shot, and that the IP will pull enough fuel to keep it running. I have not seen a dodge run yet with a shot lift pump any input on this.

tmar04

Clete, I used an airtex on my mildly modded 01 Dodge. lasted about 3k miles then crapped out! called dealer, (Northern Auto Parts, Sioux City Ia and he has a new one on the way. Probably won't be any better than first one, but gotta try it. I will post results if it goes south, you can bet on that.

Clete

Thanks for the reply, I got a FASS coming in the morning. I'm not going to take a chance on another Airtex. This guy is from Iowa and I would hate for him to break on the road. I've had good luck with the FASS, a little pricey but I've put enough on that the install should be quick.

We'll see what happens tommorrow, I hope the thing starts again and gets back to Iowa.

thumper549

This will sound ridiculuos...My own trk was doing the same thing, would drop to o ! I did the Ez thing 1st ( I am lazy) replaced the fuel filter and been hummin every since !

Dinner

If the IP is still in good/regular working order then yes it can pull enough fuel to read about 4psi I believe (give or take). This isn't good for the IP, however it still might be able to drive you somewhere, throw a new LP on the truck and away you go. And yes if the condition of the IP is good, the truck will be able to run and drive around.

Clete

No pressure to the bowl, but it got a filter anyway.

Put the FASS on it today, it fired up and is half way to Iowa now. Thanks for all the help.

Thanks
Clete