I am having an intermittent loss of power problem. If it happens on the freeway, I can barely maintain 40mph. If it happens around town, I can barely get moving. Then the problem goes away and all is good. It does not run rough, no smoke, only 70,000 miles and the fuel pressures are all normal. I read some other posts that talked about faulty MAP sensors with the same symptoms. I decided to take it to a local Cummins shop but they have no idea what a "MAP" sensor is... Can someone please help... part number? different name?

Thanks, Chris
'01 2500

 

I'm pretty sure MAP means Manifold Absolute Pressure. It measures the actual pressure in the intake manifold - go figure.

 

Most diesel mechanics, and people in the diesel world in general refer to the M.A.P. sensor as a boost sensor. Map sensor is usually a gasser term. I once asked for a map sensor at Cummins NW, the parts man asked me if that was the boost sensor.

 

Thanks CDRAM, that answers my question! This whole thing has become a big nightmare. I took the truck to Cummins NW with specific instructions, to three different people... run a quick computer check to make sure that there is not anything else wrong with the engine...i.e. fuel pump. But most importantly, I told them to only replace the MAP sensor (boost sensor). THat is it, don't waste your time on diagnostic checks, I would assume all responsibility if "my" diagnosis is not correct. I would expect an hour labor plus parts. I would do this myself but I already had an appointment and felt bad cancelling it.

So I go to pick it up last night which I had previously arranged to do... The part was not replaced, the battery was completely dead and there was a bill for $400! All of which was diagnostic time?!?! I thought I told them explicitly NOT to do that. They did not even find anything wrong with the truck after spending all that time.

I am not sure what is the correct way to handle this problem. Needless to say, I am less than satisfied.

 

I HAD A BAD MAP SENSOR THAT NEVER TRIPPED A CODE INTHE COMPUTER. HAD THE SAME PROBLEM YOU HAD, NO POWER VERY LITTLE BOOST. HAPPENED A WEEK AFTER A NEW PUMP INSTALL. THEY INSTALLED ANOTHER INJECTOR PUMP FOR NO CHARGE AND THE PROBLEM STILL EXISTED. ONLY OPTION LEFT WAS THE MAP SENSOR. NOT A PROBLEM SINCE. THIS I WAS TOLD IS A SIMPLE INSTALL ON THE DRIVERS SIDE OF BLOCK. I THINK ITS NEAR THE LIFT PUMP.

GOOD LUCK

 

Just changed the MAP (boost sensor) and everything seems fine so far, although the problem was intermittant. The part was about $85, much better than $3000 for a new pump! Cummins NW also corrected the bill and misunderstanding.

 

Map / boost sensor for a 01 is part number 05017791aa.
My 02 needs a different one .

 

Well... it ended up being the Injector pump. The dealer fixed it under a special warranty. I now have a fuel pressure guage and dual lifter pumps to help prevent this from happening again.