Engine/Transmission (1998.5 - 2002) Engine Hiccup During Hard Acceleration

[IdaH.O.Train]

During hard acceleration, like when passing someone, I have been noticing the acceleration is not smooth. There seems to be brief hiccups, where the engine feels like it misses. Any idea what could be causing this? Everything else seems to be fine.

 

[stlowry]

I've been having the same problem with mine, but it only does it while towing with my DD ultimate fueling module on. Turn it off, no problem. I'm running Holley pusher and lift pumps with about 20 psi at idle. I don't have a fuel pressure guage in the cab yet to confirm this but I believe that the pres. is dropping too low under WOT. I've got a guage on order so when it gets here and I can confirm my theory I will hopefully be able to solve the problem by installing larger diameter fuel lines.

 

[overfueled]

F. Y. I My truck did that for about a year and a half. I took it to allot of people to try to fix. No one did, I changed the lines, the pumps,( I put two on). I put on most all the fueling boxes on the market ( because I was told to). No change. It would only happen when I would accelerate hard off the line. With the F. M. S. at 63% It would run good to about 1800 rpm's caugh once run good to about 2,000 rpm caugh once again run strong to about 2,200 do it again and then run great to 3,100 rpm's. It took me a long time and allot of money to get over this. But I did. And man is it great. Does this sound like your problem? I could tell you how to fix but I can’t tell you over this form. PM me. OverFueled

 

[Turbo Tim 1]

Mine is doing the same sort of thing, if I leave the comp at level 2 or below it doesn't seem to do it. It just started after my comp got replaced because the old one went bad. I've even put on a different comp box to check the box but it did the same thing.

 

[ToolManTimTaylor]

Had a serious issue with this ... Come to find out my blue chip cover stud had wiggled out a bit and was not making full contact. Check that pump wire! It'l drive you nuts!

 

[IdaH.O.Train]

Thanks for the replies. It looks like you guys were/are seeing the problem with bigger boxes than me. I am seeing it with the EZ, so there must be a common denominator with them all. Whatever is causing it, I would just like to know and fix.

 

[Big White Beast]

Dan...

Did you ever put in a fuel pressure gauge? Even with the newer pump you got I've heard of them failing quickly. The other thing I would check is all the connections. It seems to come down to that a lot. Clean em up and put some dialectric grease in the connectors to avoid moisture. Don't forget to check the OEM connections too, they have been known to fail.



Garrett

 

[KWIKKURT]

Grease all conections and CHECK Fuel pressure during WOT. .

 

[Turbo Tim 1]

NoCalH. O. PO - Did you ever get this problem fixed?

 

[jcbrown]

Fueling Box...

... is causing engine surging. Software issue. :--)



Van Aaken is the only one I know of that has addressed and fixed this issue.

 

[WadePatton]

The only heavy acceleration issue I've had was when the Blue Chip cover wasn't making full contact. (Aside from a boost code now under investigation)



The other stumble (unpredictable) was cured by a reflash for intermittent stumble.

 

[Turbo Tim 1]

Mine is still doing something similar, it actually runs better on 2 or 3 than on level five. One time I set a p0253 code (fuel solenoid failure or something like that) the local shop that everybody raves about wanted to start throwing parts at it starting with an injection pump. So I left there and started checking the connections, fiddled with all the pins and made sure they were tight and lubed them up, checked the pump wire connection. Still haven't found the problem, I am leaning towards the reflash. One other thing, since this started I can't get over 24 lbs boost and I used to get 35 or so. Steady hiway driving the boost is the same 8-12 lbs it used to be and with the comp off it goes to 20-21 just like it used to. I felt up the booties and put a wrench on all possible intake connections and everything seems fine. It has been close to 9,000 miles since I set the code and the truck runs fine except for when I am puttin the nuts to it.

 

[kluther]

do a search on the apps (accel pedal position sensor). mine did the same thing,towing my 5-ver. recallibrated the apps, has not hiccuped since, 800 miles so far. good luck ken

 

[Blkdawdg]

ME TOO!

My truck ('02 Auto) does the same thing when I go from partial throttle, then no throttle, then partial to full throttle. I have a fuel pressure gauge @ outlet of fuel filter housing and it never gets below 12 psi. I also run the Edge COMP.

 

[WadePatton]

When mine was the fuel pump wire it stammered on levels 2-5 and the boost gauge jumped wildly. Another bit of a turn on the pointy screw in the cover fixed it.



Next time I'm really looking for something to do, I'm going to solder a real connection to the pump wire.

 

[jrandol]

Originally posted by ToolManTimTaylor

Had a serious issue with this ... Come to find out my blue chip cover stud had wiggled out a bit and was not making full contact. Check that pump wire! It'l drive you nuts!

I had the same darn thing happen to me. With my FMS I would turn on the fueling at a stoplight and the thing would add fuel at idle!! My bit on the FMS had wiggled loose and was sending funny pulses to the VP.



For a side note on pauses, I had this problem when I first put my box on (FMS premium) and called Chip. Chip said it was very important that I did not ground the ground wire out anywhere except the Black wire with Brown tracer going into the VP44. I had mine grounded on the air horn. Once I moved this wire, life was good. Apparently with a ground elsewhere, their were some RF noises that were interupting the FMS's ability to talk to the VP.

 

[Turbo Tim 1]

The ground wire thing is a good point, mine is grounded to the air horn, how did you connect up to the wire going to the VP? Cut and splice?

 

[ToolManTimTaylor]

Hmmm yeah the FMS is a sensitive unit but when she is connected fine and secure it just plain RIPS! I loctited the bajeezuz out of the studs and have not had one problem scince I found my bad stud connect.

 

[ToolManTimTaylor]

Tim, I have a Pump cover that uses an internal gounding pin.

 

[Turbo Tim 1]

OK so I am not the quickest troubleshooter in the world but I finally fixed my stumble problem and wanted to put the word out so others can maybe benefit. After checking and rechecking all the electrical connections on the truck, adjusting valves, changing filters, buying lift pumps, thinking I may have to buy a VP-44 and shaking chicken bones at the truck in a ritual type fashion I finally solved the problem with the help of these forums and Justin at Edge Products. In my case it initially wasn't the pump wire connection but the ground to the air horn (just like Jrandol said) Justin at Edge told me to put that wire directly to the battery and see if the problem went away and sure enough the stumble was gone but the truck still didn't seem as powerful as before and didn't smoke as nicely as before so I re-did the pump wire connection because I had taken it apart a few times during my troubleshooting process and was concerned about it making good contact since I re-used the old one (don't re-use scotch locks) and now all of a sudden I am worried about my clutch again. This truck once again rocks, Thank you Toolman, Jrandol, Edge and all the others that took the time to assist me in my troubleshooting and repair. I think to celebrate I might go to the 1 ton truck pulls in Greenwich on Sunday and see if I can destroy my clutch, then I have a good excuse to buy a new one. By the way if anyone is interested there are big rig truck pulls on Sunday the 24 th in Greenwich, New York, They had 60 something hooks last year including the really hot pullers and some local dump trucks and log trucks.