I have a 1997 f350 that doesn't make much boost until about 2500 rpm. I have had it to a mechanic and the only thing he can find is low exhaust back pressure. I have cleaned the tube, the sensor, the opening to the manifold, and even connected the sensor to the tube going to the MAP sensor. I also have a 1997 f250 and have swapped all of the following with no changes: PCM, IDM, EBPS, MAP sensor, and TPS. I have changed the fuel filter and clean the FPR screen. Any help would be greatly appreciated.

 

Hows the waste gate? Does it have one, umnlug it and see what happens. you did check the turbo, quick spin by hand? No banana's in the tail pipe?

 

No waste gate. EBPV is functioning correctly. Downpipe is new and cat is gone.

 

I'm sure there are others with better answers, but our Stiction Eliminator will help with turbo performance. Not saying it will fix your issue, but it may help it out.

 

How do you know it's low boost.

 

How's it run, no miss fires no restriction on the intake side, you can take the air tube off and watch the turbine spin correct? Intake leaks? you changed a bunch of parts but they have nothing to do with boost. Simple air in air out, put some wet rags in the tailpipe and listen for any leaks around the manifold, up pipes, turbo flange, do you have a boost gauge? I'm throwing alot out at ya but hopefully something will stick.

 

Truck runs fine. No missing just can't get out of its own way at low rpms. Seems like it does not downshift as much as the f250 either. This morning, I drove with the mechanic as the passenger. He read the scanner as we rode around. He said that boost peaked at 13 psi but was really low at low rpms. There were some leaks on the intake plenums but they were fixed.

 

Any pre-turbo exhaust leaks (manifolds, up-pipes)?

 

Don't think so. Mechanic said soot would be visible. Any tricks on how to check for these? Going out to try the wet towels on the tailpipe. Engine noise makes it hard to hear much.

 

Any thoughts on why the exhaust back pressure reading is low? Doesn't that have something to do with fuel?

 

There is a hole in the exhaust where the driver's side manifold meets the up pipe. I'm guessing that would be the problem.

 

that sounds like you just found your problem