Howdy all,

I mentioned this before,but the the Beast seems to have a momentary miss after putting other stuff on the trailer...

It doesn't do it everytime I go WOT,but it has done it twice out of about 5-6 times I've stuck 'er to the floor long enough to show somebody taillights.

When I slowed down for the next stoplight,and came to a stop (or near stop the first time) I can feel it missing...almost seems like it's loaded-up.
This last time I gave it a couple seconds (5 at most) to clean-out on it's own at idle (it didn't) then I popped it in neutral and revved it a little...when I put in back in drive it was fine.
It really kinda' seems like the PODs are throwing so much fuel in there that there's some unburned fuel in it after a WFO run...but that doesn't make sense to me...

Otherwise it drives like a dream...throws enough black smoke to hide a battleship,rolls out clean,stays cool under WOT (1000 or so),and goes way faster than a big truck should when I stick the "go" pedal (not that I have a problem with that mind you...).

Does anybody else's truck do this? Is this normal and nothing to worry about?

Should I be looking at something besides other traffic rapidly retreating in my rearview mirror?

As usual,thanks in advance for any idea's...

Vinny

 

do you know how old the injectors are?
One of them could be getting stuck, or sticking a little.

Maybe you can back your AFC out, or adjust your timing.

 

I had something similar happen, pulled my injectors and found one sticking and spraying like a water hose.

Fixed that then it starting knocking and making noise a little while after that, found out what that was too, flex plate was not tight to the torque converter. Thought it was injectors again for awhile.

 

Does it have the stock lift pump? The stock lift pump has been known to starve the pump for fuel at high RPM, there is a piston lift pump available to replace it.

 

It sounds like it was missing at idle though, I guess it was after a WOT run though so the lift pump could be the problem. What about an electric pusher pump? I have one.

 

I'm thinking that the injectors might be about 1 year old. Not really 100 % sure on that. Vinny, you could look through the log books to see when the motor was put in, 184,000 rings my head but not sure, so that would be about 60,000 miles on them. I have not pulled them at all over that time frame to check on them.

 

Well, it sounds like the injectors probably aren't the culpret...

It does have the stock lift pump.

It doesn't have the 3k spring in the pump yet so it's not really "winding up", but from the smoke it's making...it's dropping a whole LOT of fuel in there when I press the "go" pedal.

What I'm experiencing could very well be a lack of fuel that I feel when I slow down.

Tell me more about the "piston pump"...I take it that's a different pump from the electric pump on the 3rd gens? That would be the electric "pusher pump" right?

Thanks a lot for the help everybody.

Vinny

 

I think you can just get a electric HOLLEY pump or something along that line. But mostly I don't think you need to have one that pushes so much fuel. Only need it to be around 20 psi compared to most that do like 100 psi. You would blow the kift pump if too much. I think they also go by the amount of fuel they push through, like 120 Gallons per Hour (gph). Not 100 % sure on all of that but always wanted to do something along that line.

Maybe check you BHAF to see if clogged?

Hey, maybe with a good sale of Monkey Boy, you might just jump up to Twins.

Only joking Matt...

 

I just got an electric pump with 3/8" fittings that was rated for about 5-7psi and like 72gph, I don't remember the exact specs. This was just the generic brand from checkers with a lifetime waranty. It is a vane type pump, not a solenoid type. So far it has worked well. I have it pushing through the stock lift pump, hopefully that is ok.

 

Info on the piston pump here.

http://www.turbodieselregister.com/f...ad.php?t=72247

I have one sitting on my workbench, I'm just waiting on Cummins to ship me the new fuel line.

 

I'm gonna go with the fuel pressure issue too....
There are two things that are the most likely culprit....
One is, of course, the stock lift pump. You need to hook a guage up to it and check you "at idle" pressure and your WOT pressure. You want no less than 4-5psi at WOT, more would be better.
At idle it should run around 10-12psi.

The second issue is the vane style supply side pump in the VE pump itself. If you have low FP and or volume the vane style pump is capable of pulling it's own fuel, but when run at WOT it will eventually start to cavitate. This is made worse because the OEM lift pump wasn't able to keep up at full RPM to begin with and now it's trying to catch up at idle value RPM..NOT......this results in the spazzing/missing and faultering that you describe. The fact that you are able to work the peddle and keep it running is pointing to those two issues...mine did the same thing when I romped on in real hard like doing a 3000RPM burnout run thru all 4 gears....ran like crap nearly died on me if I hadn't pumped the throttle to keep 'er running.

pb....

 

Hey Bushy,

Does Nascar Mark still work at Piers? This is the motor he sold to Scott in Vermont.

If so,I'd love to ask him some questions about it, like, what kind of cam is in this motor,and why there's a hex (bolt) head on the full fuel screw...

I don't know what-all he did to it, but BOY, this thing scoots...

I tell ya'...the chugging at idle just seems kinda' like a cam to me. It really doesn't smooth out until it hits about a thousand RPM's...so I don't see it being the idle being down 100 RPM's (but I have been wrong before).
It also doesn't do it in reverse...?

Still puzzle-fied...

Vinny

 

Yes mark is still with PDR...give a call during the day and ask for him directly and I'm sure he'll help you out all he can.

pb..