Engine/Transmission (1998.5 - 2002) stumble. ?

[DIESELWRKS]

question on troubleshooting I have a stumble on the truck when I accelerate quick usually in 5th to 6th gear. usually putting me around 2k to 2400k rpm. I have 16psi fuel pressure going to the vp on wot. I have cleaned and checked my TST connections and map connections. I have noticed that compared running the TST on 9 this is the worst stumble not as bad or as long. once I get through the stumble the truck is fine. because I'm at the speed I want and I back off the throttle. so either this is APPS but have not thrown any codes. or my 2nd replaced vp has almost 65k miles on it. but still no codes. does change slightly with weather. but really the cold weather we do get I dont really punch the throttle to hard anyways. any Ideas on what to check or clean. rather go the long route and check what I can before I put more $ in it. still saving for the hamilton cam:-laf. also I have not tried to reset APPS yet



2002 HO 6-SPD LB 4X4 QC HTT 62/14 SB-DD3600 TST PM3/*REVO-BETA*SMARTY MACH 4'S, RINGED AND STUDS, AFE/2 " FTE 6" STACK D/PRICOL GAUGES, FASS 150, VULCAN 1/2 DRAW-STRAW, 3/8 FUEL LINE, DSS-BOX DT PRO-FAB TRAC BAR, CONV-T STYLE STEERING,DUNKS TRACTION BARS, AIR BAGS,17'' KMC BLACK HOSS, 37" TOYO MT'S 6" RCD LONG ARM LIFT. :-laf... THANKS RIP DiPricol Gauges

 

[DFerverda]

That is where i would start, clean the battery posts and bolts, clean and use dielectric grease on the grounds and reset the apps.
I had a slight stumble that left after a good cleaning of the electrical system.

 

[DIESELWRKS]

batt's are red optima's they are good to go. checked that. the grounds I have not. will check this

 

[DIESELWRKS]

so after checking contacts, negative grounds, sensors. resetting apps nothing was changed. so I started messing with my TST no change still have a lighter stumble on lower settings on TST. now with the smarty turned off no stumble and slug of a truck. I usually always have the truck on SW 9 changed the truck to SW 5 same sub settings and the stumble is completely gone. so now I'm stumped. before the truck was fine with SW-9 now seems to be asking to much. makes me wonder I have noticed this since I have put on bigger tires. 37's now I have more load need more to get going etc. but I know I have plenty of fuel reaching the Vp, so I'm wondering now is this a air starvation stumble/ or vp and demand of SW-9 is not able to keep up. still no codes. ???? love my smarty and dont plan on loosing it.

 

[DIESELWRKS]

thought I had it pinned down now it seems I'm getting this stumble/miss with all of the catcher numbers. with the smarty off TST up on 9 nothing at all no stumble except truck feels like a slug. forgot what it is like to not have the smarty. so I have no clue now where to look.

 

[jdross440]

Mine has been doing kind of the same thing. See my post https://www.turbodieselregister.com...ion-1998-5-2002/220713-p1689-p0336-codes.html. I took it to the dealer yesterday after getting tired of messing with it. They called and said the Turbo Boost sensor was giving erratic readings to the ECM causing it to turn fuel off momentarily. They didn't have the part but got it today and they called a few minutes ago saying it was running good now ($433 they said). We'll see after a few days. You may want to check this item too.

 

[DIESELWRKS]

that is alot of money for a map sensor. I replaced mine withing the last year. I think what I need to do is remove tst then install smarty and see if I get this problem. then I have narrowed it down to electronics. this would be shooting at a ecm. now even though I dont get these issues with just the TST off or on but they are connected in circuit. so I want to know if the stumble will be there with no box and just smarty. I guess time will tell. just curious but why didn't you just buy the map sensor yourself and install it at your price and not the stealership's.

 

[jdross440]

I didn't know that was supposedly what was wrong. I was suspecting the ECM. By the way, the map sensor didn't fix it. It stumbled before I got 100 yds. They told me when they went to start it to move into shop, it wouldn't start and had a P0370 code. When they reset it, it started. When I went to pick it up, it did the same thing. I am pulling the injection pump this weekend and sending back to Midwest Fuel Injection for them to check out.

 

[DIESELWRKS]

I didn't know that was supposedly what was wrong. I was suspecting the ECM. By the way, the map sensor didn't fix it. It stumbled before I got 100 yds. They told me when they went to start it to move into shop, it wouldn't start and had a P0370 code. When they reset it, it started. When I went to pick it up, it did the same thing. I am pulling the injection pump this weekend and sending back to Midwest Fuel Injection for them to check out.

good luck and sorry for the bad luck. let us know