1999 cummins losing power
 

hey guys looking for some help cant seem to figure this one out. all started one day i was driving around and all of a sudden i completly lost power it would barley move, for about 15 seconds then took off like a jet. that was a month ago. now every once in a while when i first get in it to go to work it starts up great then i go to take off and same thing, has no balls, wont spool up the turbo, wont do anything and my fuel pressure guage stays 10-15 psi during all this. on top of it ever since it did it the first time i dont feel the power i used to even when its not acting up. i do have a edge programer and airdog lift pump. only code im getting is p0236 MAP sensor too high too long. dont know if that hass to do with it or not. help is strongly apreciated. also im not seeing any white smoke if that helps any

Have you checked your TPS? Sounds like your getting dead pedal.

Wen it is acting up i can still rev it up in park just fine but once i go to drive it is when it doesnt do anything. Im going to guess it may be a fuel issue but i dont know much about diesels. It will drive it just takes forever to get moving it doesnt cut out or anything it just has the power of a prius for 5 min then it takes off.

Do you have any kind for module on the truck like edge, bully dog or banks wire tapped in to the injector pump? I have my banks module tapped into my injector pump and the module started acting up and caused my truck to do the same thing yours is doing. I had to send it back and have it reflashed.

Well WTF is new, I wrote a kick-ass response to your question and then when I went to post it, the f'ing computer told me that I wasn't logged in. Right... whatever. So, it all disappeared! Great. Well, here's the quick and dirty version...

Yeah, it's your MAP sensor. I had the exact same problem. Truck sits and idles fine, but it can't get out of it's own way, and snails move faster. Downright dangerous to drive anywhere it's so slow. You have NO idea how hard it was to figure it out on my stupid truck though, b/c my truck didn't set a code for it, it set over a half dozen codes or so in both my Chrysler PCM and my Cummins ECU (A total of like 14 codes). You are lucky it's telling you that your MAP sensor has a problem!

Anyhow, replace it and clear your codes. You should be golden. :jump:

The MAP sensor screws into the side of the engine just below and behind (to the rear of) the fuel filter housing assy. It will require unplugging the weatherpack connector from the sensor, and use a 1-1/4" deep socket to unscrew it.

Last time I checked (that was like 4 years ago), the MAP sensor cost about $150 from the dealer. Not sure if you can get them aftermarket cheaper or not. Cummins parts are such a rip-off.

Let me know if you get it fixed and if I'm right. (I'm 99.9% sure that I am.)

All the best, :rocking:
AJ

Ok cool . Yes i do have a edge programer im going to try this map sensor and ill keep you updated latly its been driving better but still dont have the power power it used too . Ill do that tomarow and see what happems thanks

I'm no expert on the programmers, but if you can take it out of the loop (so to speak) completely, that might be wise to do before you go throwing parts at the truck. Seems to me that most of those things are plug and play, so you should be able to remove it pretty easily.

Sometimes the aftermarket stuff can screw up and cause a lot of headaches.

If I were in your shoes, I know that I'd want to be confident that the aftermarket programmer wasn't responsible for the lack of power change before I spent a lot of money on other parts trying to fix the problem that might be caused by the aftermarket programmer.

alright time for a curve ball. the map sensor was removed, a nipple was installed for the aftermarket boost gauge it appears the connector now has a dummy that its plugged into? and they tapped in some other wires and used butt-connectors maybe thats where the problem is. this truck is a f-ing nightmare i miss my duramax! anyhow dealing with what i got...also noticed that there may be a wire tapped into on the injector pump i may be wrong though if theres any thing i can take pictures of to help let me know, what are you guys thinking now? it hasnt been doing the weird take off anymore but it still dont have the power it did last month. it doesnt blow the smoke out like it used to when turned up and it doesnt throw me in the seat. heeeeelp! :argh:

Fuel filter?

The factory fuel filter was bypassed for the air dog in which i ordered a new filter and seperator they will be here tomarow, i did think about that too but dont know why im throwing a code if the filter is the problem? Maybe the code has always been there even when it had the power the check engine light hasnt come on it this entire time but the light does work. Thats somthing else too if the airdog bypasses the factory fuel filter/separator then how does fuel keep getting to it? The line that went to the injector pump is disconnected but fuel doesnt come out of it but if i open the valve to drain water fuel comes out. Sorry if im confusing anyone just trying to be thorough.