Engine/Transmission (1998.5 - 2002) Engine misses under load in high gear

[JSamples]

My 02 Ram started this problem where it would miss slightly under heavy load in 5th and 6th gear a couple months ago. It would seem to clear up once the motor reved higher. Its gotten a lot worse in the past few weeks though, when I hit the interstate and go to 5th and 6th gear and try to get on the throttle heavy, my truck shakes and bucks pretty badly, to the point where im afraid to run it hard in high gears. When I turn my Edge box down it helps it a lot but on 0 it still bucks and shakes pretty noticeably. Also, sometimes if I lug the engine in 4th or 5th and barely hold the throttle to try to save fuel, it does this problem slightly. Other than that, the truck runs great and has as much power as ever. If I decide to race someone it runs great until I hit high gears then it misses pretty bad. Ive ran fuel conditioners of every type with no results too, now im stumped. My only thoughts are my injection pump may be going bad, but its not even a year old yet (Hot Rod 44), but I checked it for codes and it didnt have any codes stored in the computer, so that leans me away from that. It seems like it started a month or 2 after installing my 100 h. p. injector tips, maybe its just overfueling too much? Or could something be getting dirty or clogged from the extreme overfueling over the past months?The filters and fluids have all been changed religiously, and my fuel pressure is stays between 16 and 22 psi at all times. My truck is just about to hit 90,000 miles. The peoblem seems to happen mostly above 15 pounds of boost also. When it does it, it kinda comes and goes, sometimes clearing up for a few seconds then coming back again, and sometimes just slightly missing and sometimes shaking the whole truck badly. Ive read a couple posts of others with this problem, but never saw a solution found, anyone have any idea what it is? If its my pump id like to know while my warranty on it is still good lol.

 

[blacksheepdiesel]

Get a buddy with an 98. 5 to 02 manual transmission truck with no symptoms and swap his APPS onto your truck. If it still happens I would call Edge. If not, pm timbo here on TDR about an aftermarket APPS.

Godspeed,
Trent

 

[JSamples]

So youre saying it sounds like a bad apps sensor? Thats one of the few sensors ive never changed.

 

[acook]

I've been chasing the same problem on a customer's truck. Will be monitoring this thred to see what solution you may come up with. Will be changing the apps at the first of the week just to see what happens.



Good luck

 

[JSamples]

Well let me know how changing the apps goes. I ordered one from advance but it won't be here till next Monday. 450$ for the damn thing, but I do good business with them and they'll let me send it back if it doesnt fix it so its worth a try to see if it runs any better. In the meantime I suppose I'll research the subject more and see if I can come up with any other causes for this annoying problem.

 

[C4gan]

I have this exact same issue. Except mine is an automatic. I replaced the APPS last week and it was fine for about 100 miles. Is it possible that it can be a timing issue? It seems that the problem in my truck only exists when there is a certain amount of load on the motor. . Any thoughts?

 

[JSamples]

Well Im still wating on my new apps sensor so I havent got to try that yet, but im actually hoping thats what it is at this point. I asked the local Cummins guru around here and he said hed never heard of an apps causing this problem though. Someome told me it was my injectors going bad but I figured that would make it run bad all the time. I went out and tried to create the miss while driving and I actually can make it do it in any gear, I just have to load the motor pretty good and get boost up in the 30's, its just not as noticeable in the lower gears but its there. So I guess I can further define the problem as just a high boost, high load miss. Whether that helps me with a sloution I dont know lol. But I suppose trying the apps sensor is my next step, if that doesnt work maybe ill pull the injectors and have em tested to see if theyre sprayin good. In the meantime im gonna double check it for codes witha scan tool and see if I can maybe come up with something there, maybe see if any sensors are out of range.

 

[GCULP]

it might be an outside air temperature issue, my truck has started bucking slightly since it got cold lately, I am waiting till it warms up a bit to see if it goes away.

 

[JSamples]

Yes I suppose that is what I will do now, because my new APPS sensor came in early today and I put it on before I left work. It DIDNT fix the problem at all, my truck still runs exactly the same, no worse, no better. Besides testing in warmer weather, im considering removing and having my injectors tested, and possibly using my warranty on my Hot Rod injection pump while I still can. Besides that, I have no other things to try that I can think of. Anybody wanna throw me any other possible causes? Lol im very tenacious about an annoying problem like this, im determined at this point to fix it so any ideas would be appreciated.

 

[mhenon]

Have you checked all grounds like battery, alt, ECM, PCM, etc. ? Sounds like a bad VP to me but you didn't get any codes so I'm thinking it's electrical. Good luck and let us know what it is when you figure it out.

Mike

 

[Huff N Puff]

Have a few questions,

How are you supplying your fuel pump,did you use the stock fuel module to supply the pump or did you drop a larger line into the tank. Have you tested the fuel delivery VOLUME AND PRESSURE.

 

[JSamples]

Yes ive checked all the grounds and electrical connections recently. Ive watched my fuel pressure but am confused as to how to check for volume. My fuel pressure never goes under 16-18 psi though.

 

[mhenon]

JSamples... have you tried removing the Edge altogether? I just re-read you first post and it sounds like things got better as you toned down the Edge. Try getting it out of the loop and see how it runs.

Mike

 

[JSamples]

Its still there with the Edge out of the equation, thats what I tried first. However with the additional fuel from the Edge, the problem gets worse, but with most problems on these motors, additional fuel usually will make a small problem worse.

 

[BEnglish]

I’m just throwing this out there.

You mention it only happens under high boost, have you checked to make sure all your intake connections are good?

 

[Underwood Tire]

we had one in the shop today doing the same thing. we found a bad wire on the rear speed sensor. we replaced the wire and took care of the issue. ( 1/3 throttle miss under load) the codes were p1693 & p0500

hope this helps

Joe

 

[dknoch]

Mine has done this for a while too. I took all the timing out of the equation with the Smarty and it it runs fine. As an experiment, I put a resistor in the IAT sensor wire to trick the computer into thinking the air was warmer, loaded a timing Smarty sensor and it ran fine. Like you, I just put 105 hp injectors into it and thought that may be the problem. What I thing is between the injectors and the cold weather timing advances quite a bit, then add a chip or programmer and problems! Good Luck

Dan

 

[Huff N Puff]

To Test Volume

Yes ive checked all the grounds and electrical connections recently. Ive watched my fuel pressure but am confused as to how to check for volume. My fuel pressure never goes under 16-18 psi though.

You need a clear gallon jug,extend a fuel line out of the filter into the bottom of the jug,power the pump up with a jumper,you should get 1/2 a gallon in 30sec with a higher volume pump,it should be solid fuel if its real frothy, the pump is having problems on the suction side.

 

[C4gan]

Underwood tire,
How did you find the bad wire on the rear speed sensor? I have had the same codes for 2 years and replaced speed sensors and the sensor on the side of the trans and could not figure out what the issue was. did you just do a continuity check of some sort? Can you explain how you derived at this conclusion?
Thanks
Chris

 

[JSamples]

Yes please elaborate on the bad wire and speed sensor as I have not even considered that to be the source of my problem, but my truck has the same codes in the computer now. P1693 and P0500, I figured the 500 code had more to do with changing my tire size though so I didnt bother with it. Where is the speed sensor and wire you talk about though? If I could fix that code from coming up id be happy, even if it didnt fix my drivabillity problem, but that would be great if it fixed that too!