Something odd happened this morning. I packed up to head for Ontario, OR today. So my truck was parked in a unheated shop where the temperature was 44*F. Fired up move out on the yard to load up some old tires and wheels. Yeah my old Cooper STT and white spoke rims are gone! Then parked back in the driveway. Wait for MoparMom to get together and left. Well the first 5 miles going down the road if I throttled it at all it was bucking or surging just enough that even MoparMom asked what was going on. Which I told her I didn't know. I had 17 PSI fuel pressure. Rolling light to build engine heat. But unusual to feel it surge like that. After it warmed up fully it was gone never seen it again. Even after getting cold down in Ontario, OR and firing back up ran fine. 

 

I figure I would post this up maybe some else seen or had something like this happen.

Michael,

 

Could you see the surge in your boost gauge?

No. When the truck cold I typically hold my boost down below 10 PSI till it warms up. As for today it didn't do it at all. I fired up and left towards Riggins, ID and on issues at all.

Bucking and surging are two different things to me. Surging is a fuel quantity variance for a constant load, and bucking is a fuel delivery issue, where fuel starts and stops quickly.. Surging is "smoother", as there isn't a fuel delivery issue.

Which do you think it was?

My first thought was you had some fuel flow issues, possibly due to gelling. The one time I gelled it was a buckin bronco. Where is your pressure sender?

Fuel Temp was at +44*F from a unheated shop. Less than 3 miles from home. Current temp when I left the house was like +27*F or so.

 

Fuel pressure sender is on the fender. (Needled and Snubbered)

 

 

My first thought was you had some fuel flow issues, possibly due to gelling.

 

 

If it was a gelling issues it should of happen in New Meadows at -3*F temperature where it ran just fine.

Where is the pressure sender in relation to filters and such? Is it from the line post pump? Or the port between filters on the pump?

 

1/4 tank issues? You were low when you got back right? I wonder if the cold was doing something funny??

 

Do you think it was bucking or surging?

 

Odds are it was nothing, but if your anything like me your going to be thinking about it for a while.

Where is the pressure sender in relation to filters and such? Is it from the line post pump? Or the port between filters on the pump?

 

1/4 tank issues? You were low when you got back right? I wonder if the cold was doing something funny??

 

Do you think it was bucking or surging?

 

Odds are it was nothing, but if your anything like me your going to be thinking about it for a while.

 

(all questions separated per line)

 

About 3" from the VP44 in the main line after the last fuel filter (stock can).

 

Yes, It is in the line post pump and post filters.

 

No. It's not in between filters.

 

5/8 of a tank when I left.

 

Yes, I had 1/8 of tank with the low light on when I hit Riggins, ID for fuel. No issues that morning.

 

If the cold was doing something funny you have to remember it was 44*F inside the shop where the truck was parked. The outside temp here at the house was about 27*F. It had the issues here near the house but by the time I got to New Meadows proper it was -3*F so it should of really shown up then but never did.

 

Hard to explain more like a shuttering motion when you gave it throttle. If you backed off it ran fine. Once warmed up it was fine. But again it never happened again.

 

Oh for sure I'll be thinking about it.

 

VP44 is just to the left and the stock filter can to right.

It's a Chrysler product. Must be the ballast resistor... LOL

 

Ed

I missed the adding throttle part earlier, that is inline with fuel gelling.... But we know it most likely wasn't (99.9%)... But what that does it make me think it was an issue between the psi sender and injector... Could be anything...

Original injection pump?

Not sure if it's the same type of surge, but we seen this happen on a vp pump that finally threw a p0370 code. Took around 3-4 months for the code to come out, first it surged only on rare occasion at higher rpm's, progressively getting worse, then it finally died.

I missed the adding throttle part earlier, that is inline with fuel gelling.... But we know it most likely wasn't (99.9%)... But what that does it make me think it was an issue between the psi sender and injector... Could be anything...

Original injection pump?

 

No. The OE pump failed at 50k miles under warranty... This started me down the windy trail of Cummins engines and the birth of the web site. The current pump has 190k miles on it and still going. No error codes or anything else.