Intermittent loss of boost while towing - Diesel Forum

Rat Trap · 10-28-2009, 12:11 PM

First post on this forum so don't flame me too bad.

I have searched a little, found some of my symptoms but not all.

My truck is an 03 f350 4x4 6.0 torqueshift trans, 83000 miles, edge with attitude programmer.

My primary problem is while towing into the mountains, the pull always starts good running 65-70 up the hill, usually within 1-2 miles into the pull the boost will start dropping from 26-28psi down to 8-9 psi and stay there speed drops down to around 30-35 rpm around 3200-3500 2nd or third gear. Get to the top of the hill starts picking up again runs fine for a while it may pull the next hill without any problems or it may do the same thing again.

Second problem happens around town, cruising 50-60 on a slight incline, roll slowly into the throttle I get a slight bucking condition, lift out of the throttle it goes away.

New EGR valve, new hp oil pump, turbo cleaned 6 mo ago, air, fuel and oil filters all changed 1500 miles ago.

I thought it might be the edge so I uninstalled it, but it still does it.

No codes stored.

Thanks in advance for any info.

cmf250 · 10-28-2009, 01:50 PM

might be a bad turbo. my truck did the same thing when i was pulling my travel trailer. no matter what setting i had my programmer on no power, took it off no power. i took it in and they told me it was a bad turbo half got it replaced it pulled fine but it started puking. got it at dealer for a new egr cooler and oil cooler.

Rat Trap · 10-29-2009, 10:05 AM

Thanks cmf250, does anyone know if the map sensor or ebp sensor can cause something like this?

**teamroper60** · 10-29-2009, 10:53 AM

Has your truck been reflashed with one of the "inferred EBP" flashes? If so, then I doubt your problem is the EBP. If not, then the EBP could be part of the problem.

But it sounds more like a fuel related issue to me. Like the engine is starving for fuel. You may have a weak fuel pump. I would want to see what your fuel pressure is under those conditions.

Rat Trap · 10-29-2009, 11:30 AM

I believe it has had all the recent re-flashes, how can I check fuel pressure?

**teamroper60** · 10-29-2009, 12:15 PM

You'll have to put a gauge on it. There are no sensors that monitor fuel pressure. Since you need to see what the pressure is under a load, you will need to get it into the cab where you can see it under those conditions.

6.0 tech · 10-29-2009, 01:04 PM

on the secondary fuel filter housing there is a 6mm allen plug on the side. puull that out and make a gauge to go in there. pressure should be 50-55 psi constantly. ford says to replace the pump if pressure drops below 45psi at any time.