[Nuke Proof]

Okay this is weird.
Occasionally my truck (00' five speed with Fass 150/95) will crank excessively before it will start (for about three seconds). Then the next time it will start normal. It will do it whether the truck is hot or cold, been sitting for ten seconds or ten days. There is no rhyme or reason as to why this is happening.

Fass system is less than 6 months old and is working with no problems.
No codes with Innova 3130 scanner.
Batteries are in working order and terminals are clean.

Any help would be appreciated
Thanks
Darin

 

[Nitrous340]

How many miles on the VP? There could be a couple things... Either the VP is slowing dying, which mine did over a course of 2-3 weeks. It didn't throw any codes, just wouldn't start easy and then once you shut it off you would have to waite 6-10hr before it would restart, or try to bleed the injector like crazy...

But it sounds like you might have small leak somewhere that possibly isn't noticable. The VP has a return line off of it, its the big banjo by the supply line. Its bigger cause it has a check ball that is suppose to keep pressure in the vp when you shut the truck off to keep its prime.
I did have somewhat of the same problem a few months ago, I replaced my injector cross over tube O-rings and it fixed the hard starting. There was also a some crud on the tubes that I cleaned off.

Dont try to buy these O-rings from a Dodge deealer..... they charge about $8 for ONE ring, I got all six from a cummins dealer for $8. You could prob also get the return banjo for $15-20.

If the VP is somewhat newer I would try the cross over tube o-rings.

 

[dozer12216]

Try parking downhill and see if porblem presists. A connector tube O-ring will cause along with banjo bolt at pump or at back of head. Also the three way fuel line at back of head. Sometimes you can see a very small weepage at point of leak. System will pull air into fuel return easier than pushes fuel out. Experience has proved.

 

[Nuke Proof]

Thanks for the replies. Sorry about the delayed response, I just got home.

The VP44 mileage is unknown, so I have to assume 145k.

The Fass System was put on in Jan because the pressure was below 10 psi.

You guys mentioned the cross over tube, forgive me, but this is the first time I heard this. What does it cross over between?

The 3 way block on the back of the head...is there an easy way to view that or is it literally on the back of the head, meaning I have to be a contortionist.

Downhill...nose or tailgate down?

Thanks again guys I really appreciate the help.


Edit: I forgot, I swapped the fuel relay for another....surprise, surprise...the problem persisted.........hehehehe

 

[jwalth02]

Point it nose down, also you can try leaving your fuel cap unscrewed a little cause you could have a venting issue causing vacuum to suck fuel back down the line.

 

[Nitrous340]

The cross over tube connects your injector line to the injector, it sits in the head.

 

[totalloser]

I think the problem is the FASS. Or VERY LIKELY it is. Not that it's not fixable, but excessive pressure in the low pressure side of the fuel delivery system makes for hard starts. FASS has a wiring diagram for a fix for this. I suspect it kills the FASS on starting to prevent the hard starting.

Simple verification: Unplug the FASS and see if you get a hard start. Obviously don't run that way, but just to diagnose the problem.

This problem drove me nuts 'till I figured it out. I think the hard start sneaks up on you- in other words, it doesn't start happening for a while which makes it that much more of a devil to figure out. I put a kill relay on my second LP to drop the pressure on startup and no more problems.

 

[DodgeMech]

yeah, there is a diagram of the switch totalloser is talkin about floatin around somewhere...:thumbsup: