Engine/Transmission (1998.5 - 2002) Odd Sound @ Higher RPM - like a miss ?

[Joe Mc]

Just noticed the other day. Comp @ 5-5, mat the go pedal around 3k its like there's a miss? Kind of sounds like "brraaa ba ba braaa ba ba". I know stupid but no other way to explain. I thought it was because I had the air on and never really ran it out before with the air on, but today - no air - it happened again - Comp 5-5, and from a dead stop mat the go pedal and around 3k same thing then trans hit second, I let off of it and the idle was loping a bit till I increased the go pedal a bit then it smoothed right out?



I had posted right after I installed the new VP (SO-VP) about a lope @ idle that would happen if I started it up and put into "D" before the oil pressure reached 25-30# - it would lope, then if I put in "N" as soon as oil pressure reached normal (it only takes like 5-8 seconds before the oil pressure is @ 40+ from start) all is well?



The truck never did any of this w/the old VP (also SO-VP) so I'm wondering if anyone knows WTF is going on here? See sign for Bombs all of which were on way before the original VP died on me.



Thanks,



Joe Mc

 

[MAllen1]

I've never had it happen on a diesel, but, from the way you are explaining the sound and the fact that you are at 3000 RPM, I would guess it's a governor or fuel control to keep from overreving.

 

[Joe Mc]

OK I guess I didn't make it clear what I'm experiencing "never" happened before, as in with the original VP. I'm hoping I'll get a reply Monday from the folks I purchased the new VP from.

 

[Joe Mc]

OK I stand corrected and very appreciative. Duh, I guess I just never noticed the miss type thing before (Odd?). But after looking at my dyno sheet from Spring Fling 07 (see attached file) it appears HP & TQ peaked @ 2. 75 - 2. 80 X 100 RPM = 2,700 - 2,800 RPM.



I still have to figure out the lopey idle when I pop into "D" before oil pressure comes up to normal psi and/or when engine is wound up full tilt if I let off the go pedal quickly. Any ideas?

 

[DFerverda]

Hi Joe, After your post about the lope, i too have had it happen a few times. It was when i started the truck,(warm) I always let it idle a few minutes before taking off cold, so i don't know if it will do it cold.
I bought my vp from MWFI, i think you did also?
If you put it in gear as soon as it starts it will go ROMP, ROMP,ROMP, Kinda catches you off guard. I don't know if it will smooth out if you leave it in drive.
I don't have a comp, and drive the truck pretty easy these days, but had no other issues or misses.
Keep us posted what they say.
Dirk

 

[Joe Mc]

Got mine at thoroughbreddiesel

Diesel performance accessories for Dodge Cummins, Ford Powerstroke, Chevy Duramax



Dirk - Glad to hear at least I'm not the only one with the lope. Will keep posting if/when I hear back from TBD.



Question - I know you said you don't have a comp and are driving pretty easy these days, but do you ever recall having the lope appear after having the engine wound up and letting off the throttle quickly?

 

[DFerverda]

I will let you know tomorrow.

 

[DFerverda]

I gave her a good run this morning, nothing, wound it up hard and dropped the peddle, normal. Tried in 1st, punched it hard and when it shifted to 2nd, let foot slide off peddle and dropped it hard, just normal did this on all gears.
I would pull off the comp and see what happens.

 

[RolandJ]

I have the same problem with my VP stock one never had aprob . Then i put HO VP and at between 1500 and 1800 there is a miss of some sort. I got mine from Industrial sent it back tested it they said i installed it wrong and was installed again and still does it. I had spoke to someone while back and they dont like the HOs for different reasons ones being the sorta miss. Its hard to explain the sound, just not what it did stock.

 

[Joe Mc]

Roland,

Your 02 had and HO VP stock - yes? I'm wondering what the heck is the deal with these remanufactured pumps that they'll do this when the stock ones never did? Anyone have a clue? ? ? Frustrating . . .

 

[RolandJ]

Joe, I put the HO in and now it does it #@$%! never missd a beat or made a sound w the OE pump

Roland,



Your 02 had and HO VP stock - yes? I'm wondering what the heck is the deal with these remanufactured pumps that they'll do this when the stock ones never did? Anyone have a clue? ? ? Frustrating . . .

 

[Huff N Puff]

You are pulling air

OK I stand corrected and very appreciative. Duh, I guess I just never noticed the miss type thing before (Odd?). But after looking at my dyno sheet from Spring Fling 07 (see attached file) it appears HP & TQ peaked @ 2. 75 - 2. 80 X 100 RPM = 2,700 - 2,800 RPM.



I still have to figure out the lopey idle when I pop into "D" before oil pressure comes up to normal psi and/or when engine is wound up full tilt if I let off the go pedal quickly. Any ideas?

After I get on my throttle hard with the box on 2 or higher if I let of quick it will die and I have to get out and bleed the injectors to get it running. I just let of the throttle easy.

 

[Joe Mc]

Huff N Puff - Tim did my trans too, good guy.

So, I'm pulling air when I jump off of it - OK. What about the lope when I start up and pop in gear too soon before oil pressure is up - can you try this with yours just to see if I'm all alone on this one. It really bugs me, I don't put into gear until the pressure is normal - no big deal - it just bugs me cause mine does lope if put into gear too soon and I've never heard anyone complain about this and haven't got a solid answer if it's happening to anyone else. Thanks

 

[RolandJ]

Huff N Puff - Tim did my trans too, good guy.



So, I'm pulling air when I jump off of it - OK. What about the lope when I start up and pop in gear too soon before oil pressure is up - can you try this with yours just to see if I'm all alone on this one. It really bugs me, I don't put into gear until the pressure is normal - no big deal - it just bugs me cause mine does lope if put into gear too soon and I've never heard anyone complain about this and haven't got a solid answer if it's happening to anyone else. Thanks

Its annoying the miss that it makes box on or off smarty loaded or unloaded and no codes

 

[Huff N Puff]

You might be pulling air on start up

Huff N Puff - Tim did my trans too, good guy.



So, I'm pulling air when I jump off of it - OK. What about the lope when I start up and pop in gear too soon before oil pressure is up - can you try this with yours just to see if I'm all alone on this one. It really bugs me, I don't put into gear until the pressure is normal - no big deal - it just bugs me cause mine does lope if put into gear too soon and I've never heard anyone complain about this and haven't got a solid answer if it's happening to anyone else. Thanks

You need to do an air check on your fuel delivery system. You should also let oil pressure come up before you put it in drive.

 

[Joe Mc]

You need to do an air check on your fuel delivery system. You should also let oil pressure come up before you put it in drive.



Sorry, how to do, and what is an air check on the fuel delivery system? I have a GDP-392 mounted on the frame by the tank, w/remote spin on FF about 12" away from the GDP pump, all big lines from draw straw to VP.

 

[DFerverda]

I think what he means is to look for air bubbles in the system. One way that comes to mind is pull off the line at the vp and add a length of clear vinyl hose, tap the starter and let the walbro run, either in a gallon jar or make the hose long enough to reach the fuel fill and just cycle it back into the tank, if there is any air being pulled (which has to be on the tank side of the lp) you will see bubbles in the hose.
Dirk

 

[Huff N Puff]

Dirk is Right

I think what he means is to look for air bubbles in the system. One way that comes to mind is pull off the line at the vp and add a length of clear vinyl hose, tap the starter and let the walbro run, either in a gallon jar or make the hose long enough to reach the fuel fill and just cycle it back into the tank, if there is any air being pulled (which has to be on the tank side of the lp) you will see bubbles in the hose.

Dirk

Dirk's way of checking for air will work,The way I like to do it is to extend any length of hose to the bottom of a large clear jug, power up the pump relay and let the pump run,after the line purges the jug should fill without any bubbles appearing in the jug.