On my past two trips towing the trailer (toy hauler, 7500# GVWR but usually only loaded to about 6K) I seem to have lost some power somewhere. The grades are suddenly noticeably harder to pull and I've found myself dropping to 2nd gear when I've never had to before. I thought it might be the air filter, it was filthy after the recent fires so I replaced it, but it didn't make any difference.

What else can I check? Truck has 104K miles on it. Fuel filter was changed 4K ago. Boost and FP readings are normal. The only thing that was changed recently was a new lift pump and I don't see how that could have an adverse affect on my power.

Thanks.
Russ

 

Smoke soot is pretty fine stuff. I would check the IAT sensor and see if it is dirty. I have heard this can cause a problem. Takes about 10 minutes. Here is a little info on that.
http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm
My $0.02 worth.

 

There might be a chance that you got ahold of some dirty fuel (fueled right after underground tank was filled?) You might try changing your fuel filter. Pretty cheap compared to a few other things. Just a thought.

Good luck.

Hunter

 

I cleaned the IAT sensor 2 or 3 months ago.

I can't crawl under the truck right now to check, but does my '99 have a cat? I was thinking maybe it's clogged... I have noticed slightly higher EGTs (about 50 degrees) when pulling the big grades so I'm thinking there might be an airflow problem somewhere. I've been putting off the purchase of a new exhaust system for almost a year now (muffler has a nice rattle) but maybe it's time for me to finally bite the bullet...

Thanks.

 

Does a 99 have a catalytic converter?

 

I don't think so. We do have a resonator that looks something like a catalytic converter. I just replaced my exhaust and that is what I had. If your exhaust is rattling inside you might have something that has come loose in the muffler and is blocking the flow. If that were the case I would get it replaced. Backpressure is not a good thing. If you do find that you have a blockage in your exhaust it could be causing sensor fouling because soot is blown back into the intake during valve overlap I would check the IAT again.

 

I also have a 99 that seems to have lost some power. Don't really notice it until I try to go up a grade. Seems to shift down earlier (auto).

Haven't pulled anything since last November, Pulling agian in April.

Had it at the dealers but they didn't notice anything.

Because I havent had my truck that long, I'm wondering if I'm just used to the power?

 

Here try this it could help.
https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

lost power slightly higher egt's is your boost normal or off a little.... maybe a loose intake tube boot?

 

Have you checked the Map sensor?

The 98.5 to 2002 trucks don't use a cat.

The 12 valves did prior to 98.5. Also if you have had an issue with a bad lift pump and the injection pump has been running low for fuel pressure it could have hurt the VP44.

I'm not trying to tell you you have a bad injection pump but the 99 model years had some issues, the lift pump can start it. Also if you have high miles on the truck that could add issues to the VP44.

But check the MAP sensor first, and boost pressure that will tell you if your getting fuel. Fuel makes boost.

The boost hoses and clamps can be of issue so look very close.

Also look at the air intake plate you could have a leak, I've seen many with the gasket blown out at one of the corners. Thats the aluminum plate at the head.

I hope this can help a little.

Don

 

Cool but will this adjust anything else I might not want to adjust?

What is an Apps sensor?

Thanks in advance

PS as far as I can tell Lift pump has not be replaced. New fuel filter, new air cleaner filter, cleaned sensor (IAT?) (back one).

 

Accelerator
Pedal
Position
Sensor

Computerized go pedal, no mechanical connection between the right pedal and the engine.


phox

 

Wow !

You guys are great!

I'm gonna try this right after work.

I'll let you know.