2000, 140K miles, 6 speed manual, stock chip.

This is a recent problem, maybe it has been there for a while but the outside temperature was low enough that it did not show.

I just replaced the fuel filter.

The engine surges, not much but enough to be irritating, at most 2 MPH. A rapid change, not slow and gradual which I could likely overlook.

I have a ScanGauge II connected and I see the TPS and engine load follow the surging (as best as I can tell as the gauge is time delayed a bit).

As best as I can determine this ONLY happens when the engine is fully hot, and outside air temperature is near 70 (no temps above this of late). Parking for 30 minutes will 'cure' the condition until maybe 5 minutes of driving.

Most noticeable under 'float' throttle conditions in higher gears, but have noticed it in 3rd or 4th gear.

It occurs both during cruise control and good old foot on accelerator pedal conditions.

My guess is I would not be able to force this problem today with local temps in the mid-50s.

 

hummm Any Codes?? none I am guessing you didnt mention any....
AAPS maybe but it threw me off when it only does it when the engine is warm...
IDK sorry buddy Coal Train and Dodge Trucker are your best bet here.. They should chime in on this one Shortly

 

I'm having my mechanic put his code reader on my truck this Thursday, I'll be back with the results then.

Thanks for any help.

 

Got the code reader on the truck today, No Codes.

Outside temps today, under 60 on my 30 minute drive, did not experience the 'surging'.

 

Well, I'm kind of taking a guess here, as it sounds like a few different things from the way you're describing it.

First thing I'd check is the APPS. Use a volt meter on the ground and signal wires and slowly depress and release the pedal. You should see it increase smoothly with pedal travel. If it skips, sticks, jumps or otherwise, then the APPS is probably shot.

My next "guess" would be the lift pump. If that's the original lift pump, it may be dead / dying or it's getting hot and causing the surging. Need to check the pressure to see if it's working, otherwise you might be taking out your VP44 as well.

Next, I'd be looking at the VP44 itself. If no codes are showing, then you might have a mechanical issue with the VP44....likely the diaphrahm.

Really, unless your TC is locking / unlocking (possibly a bad ground), those are the likely causes of the issue.

 

Today I noticed the check engine light was on, code is P0216. My shop manual tells me this is an fuel injector pump timing issue.

I sense no loss of power, and the engine 'seems' to be running as normal.

A week ago I put a pressure gauge on the line between the fuel filter and the injector pump and I'm getting 8 PSI or better under all throttle conditions.

I'm about to resign myself to buying a rebuilt injector pump, anyone have any other thoughts?


Thanks

 

thats the "death code" for the vp44, i would also change the lift pump while you are there to prevent another failer

 

Ordered a DDRP pump today, I'll install it mid-week and at the same time the code will clear itself when the batteries are disconnected.

I'll stay close to home, or upgrade my AAA towing to premium after the new lift pump is installed.

Now a question about the VP44: I have no desire to increase power as I have enough for my needs at present. I see there is a VP44028X pump for the 6-speed manual tranny. I have not climbed under my truck to determine what I have, and I won't until the ground dries out from our unseasonal rain.

Is there any rebuilder I should stay away from, or one I should consider? Yes, as always, cost is a consideration.

Thanks

 

Just shoot me your VIN and current mileage and I can check your truck and make sure to get you the right pump.

We have standard and high output VP's available.

 

Replaced the injector pump and have had no issues for 10 months or so.

A week or so ago I realized the truck is again 'surging' cruise or not, 50+-60 mph, flat or slight uphill, speed will slowly increase a mph or so, then slow rapidly.

I changed the fuel filter after this, but yesterday I caught the truck doing this again.

I'll get out and attempt to get more information, such as what speeds it will happen at.

Sure would like some opinions.

Thanks