Defueling?

[team_penin]

2000 f-350,w/standard tranny and no mods(friends truck) He was pulling a pretty good load yesterday and about 2500 rpm it acted like it was defueling. Just lost all power in 4th gear. Could this be something with MAP sensor or somethin else

 

[Mike]

I would guess he either hit the MAP sensor limit or he may have experienced turbo stall.

 

[team_penin]

Wouldn't turbo stall make a noise of somekind?

 

[Mike]

Wouldn't turbo stall make a noise of somekind?

Yep..

 

[team_penin]

Ok...ther was no wierd noises, no SES light no nothing just defueld (lost power) at 2500 rpm. I am thinking MAP problem but was hoping someone has had this problem and would be able to shed som light as to what to check.

This evening I am goin to check filters, oil, codes, fuel preassure and probably change out the MAP with the one on my truck and see if that cures it.

 

[scheid6996]

sounds like cavitation

 

[Mike]

sounds like cavitation

 

[trackspeeder]

sounds like cavitation

That would make wierd sounds. Check the fuel filter.

 

[scheid6996]

That would make wierd sounds. Check the fuel filter.

R ya sure, cus when my 95 did it, or i thought it was doing it, it didnt make any sound, just lost power

 

[EMD Diesel Power]

Cavitation of any sort will make noise.... and lots of it. Doesnt matter if its in a hydraulic system, PSD cooling system, or a submarine/ship propeller at high speed. Why do you think the Navy spends BIG bucks on the 688 and Trident sub propellers...... to reduce the cavitation. Noise is death.

Cavitation in a fuel system is nothing more than entrained air... would cause wierd running as well in a diesel.

Turbo stall (compressor stall) will make a boatload of noise. Sounds like an elephant fart in a truck..... sounds like God Himself farted when it happens on a locomotive (the carbody doors usually bulge out like crazy too). Turbo stall usually breaks things after awhile.

As for your problem..... does it lose power in any other gear at 2500 rpm? or any rpm for that matter?

Areas to look at could be:
fuel filter(s} plugging, (junk in tank, low fuel at the time)

the boost sensor (MAP),

Boost leak in intake system above a certain PSI/rpms

Low oil pressures and/or foaming effecting HEUI system operation

Just a start..... not much I can go on... not enough details.

 

[team_penin]

Well I figured it out! The air filter looked like someone took it out and stuck it in mud then put it back in the truck---pretty simple right. He took it to have the oil change a couple of days ago and the guy said he changed the air filter, shows on the reciept Go figure...went ahead and tighten all the boots just to be sure. Oh yeah no codes

Thanks for the help guys, turned out to be fairly simple!!