Engine/Transmission (1998.5 - 2002) Cant figure it out?

[jnelson]

Heres the problem -



Driving down the road and engine loses power - rpm stays up - if I drop it out of OD it seems to recover quicker. Engine light comes on. Happens only on occasion. Does not matter if BD box is on or off or even connected.



Went to stealer and he pulled up a bunch of codes. He cleared the PCM and ECM. He said "drive it and when it does it again we will read the codes again and narrow down the problem. "



Truck still done it at low speed (30 mph in 3rd 1500 rpm) and at 50-52 mph in OD. truck would act like it would cut in and out real fast.

But it would not leave any codes in the ECM



LP pressure is fine.

Injector pump replaced 30,000 miles ago.

Replaced APPS

Replaced Speed sensor on OD unit of transmission.

Cleaned MAP sensor

checked all connections



It seemed after a APPS recalibration it would clear up some but would come right back.



Truck ran great for the past 7-8 days since the Speed sensor install and a APPS recal. It just started doing it again tonite.



Sorry so long but if any can help



PLEASE DO!



Fixin to roll 304,000 miles.

 

[GeneralMachine]

Seem's we had the same problem with one truck and it was the boost sensor, and also the calibration was off. truck runs fine now. Harv

 

[rashwor]

MAP Sensor

My truck had a problem very similar to yours at 104,000 miles (read BUMMER! ). The dealer replaced the MAP sensor (codes set and check engine light on intermitently) at cost to me and the truck has run fine ever since.



When the CEL would come on, the truck would barely pull itself down the road on level ground at 55mph and would not climb a hill. When the light would go off, it would run great immediately until the light came back on.

 

[jnelson]

Is the boost sensor located just to the right of - and below the fuel canister . And what was the cost on the that sensor?



I would start at the boost sensor if it is cheaper than the MAP.



Would you happen to know the cost?



Im leaving to guide a hunting trip in the Texas hill country and the truck will be parked for a couple of days.



Im at wits end:{

 

[Alan Reagan]

The boost sensor is the MAP sensor.

 

[GeneralMachine]

Map sensor

It Is where you said and if I remember right it was 38. 00 And some change. Alan is correct they are one in the same. Map-Boostsensor,Good luck Harv

 

[rashwor]

Ditto...

on HWhite's and Alan's posts.

 

[Turbo Trucker]

Could it be the torque converter clutch slipping?

 

[Alan Reagan]

When the Check Engine Light came on, you said the truck would barely go down they road. That's because the truck went into the "limp home" mode. I didn't think a failed or problematic MAP would cause that but if it were getting a zero or overvoltage reading, maybe it does that to protect the engine. The "limp home" mode is why the truck didn't have any power.

 

[jnelson]

Truck still doing it.



If rolling through town at low RPM and I drop it from drive to 2nd gear - the problem goes away immediately as the rpm rises. Same thing at 52-53 mph in OD. Drop it out of OD to 3rd and problem is gone.



Still hunting and pecking.

 

[jnelson]

Just to let a few of the guys know - bought the map sensor - cost me $155. 00. Put it in and guess what - still no fix.



Took the plug off the ECM and cleand it well, cleaned the IAT, new APPS, new VSS - heck Im up to $588 and Im still hunting.



But when I find I'll let yall know.







PS



Is this one of those "Maddening" problem?

 

[CstlEng]

did you fix it yet? if not what are the new codes you got after clearing?

 

[340Mark]

Same problem

Hello I'm new to The TDR and Diesel ownership. I have had this same problem since I bought the truck in November. Intermittent power loss while at speed. I could push in the clutch for 5 seconds and let it go to idle, rev it and the power would be back.

The truck is 1998. 5 24v (stock as far as I know). It has 140k on it with a 5 Sp. I saw this problem on one of the Usenet groups, alt autos dodge or similar and the guy got no help beyond the usual "check the lift pump" "check the connections" advice.

Now my truck must have had a hard life it started spewing oil and running terrible, so I've got the engine out. I found two cylinders with gouges in the cylinder walls 90 degrees off the crank axis. I doubt the problems are related, but who knows?

It really sounds like the ECM is trying to protect the engine from itself. Just a thought but how about a stuck waste gate. Best of luck finding this one

 

[GeneralMachine]

JNelson

I was wandering if you picked up on the part of my quote that said they had to calbrate the boost, our truck was showing 22psi of boost with the truck dead. after they calabrated that the truck has not looked back except at the psd that it blew by. Harv

 

[jnelson]

What and how was recalibrated? Please enlighten me

When at idle at the stealer it registered 18 psi I beleive. Does that sound right.



Truck has been running great except at light throttle in 3rd going 30-34 and OD going 50-53.



Will roll 308,000 by lunch tomorrow.

 

[KcoleKennyc]

My 98. 5 kept cutting off and turning on the "Check Engine" light. Dealer couldn't find anything wrong. I put up with this for months, it never did it pulling or at high speed, always after slowing in town. Dealer said there was nothing wrong. Took a chance and replaced the APPS - problem solved. Been about a year or so and no more problem. The engine wasn't really cutting off, it just went to idle. Kenny N4YYX

 

[EShaw]

Replace your brake switch... ... ... . I know it sounds crazy, but humor me... ..... while driving down the road just tap your brake with your left foot while keeping on the throttle it should duplicate the symptom on command.

Eric

 

[speedracer]

No, 18 psi at idle is not right. It should show no boost at idle, 18 psi would require quite a bit of throttle(in gear, running down the road, not in neutral sitting still). I'm not familiar with this recalibrating procedure HWhite is talking about, but it sounds like you need to learn about it and have the dealer do it. If the computer's reading 18 psi at idle, I wonder what it's reading when under load? Definitely not right.

 

[Alan Reagan]

With 18 PSI at idle, the engine should never reach more load than is required for 3 PSI. At what the ECM sees at that point (21 PSI(18 + 3)) the engine would defuel.



I thought the MAP recalibrated at every start or every WOT occurance. I'm surprised the calibration can hang at 18 PSI and stay there.

 

[Marco]

15-18 Psi is OK!

Guys,

The MAP or boost sensor gives a "absolute" reading. That means at idle it reads the atmospheric pressure.



When the boost builds up it reads atmospheric + boost pressure.



Marco