intermittant low boost - Diesel Forum

66CLEVE · 02-14-2013, 11:33 AM

I am usually getting low boost, and when the rpm drops from a shift, the boost drops to the point there is no power. Anyone have an idea what the cause could be?
1997 7.3

**Justin@DP-Tuner** · 02-14-2013, 02:30 PM

Quote:

Originally Posted by 66CLEVE

I am usually getting low boost, and when the rpm drops from a shift, the boost drops to the point there is no power. Anyone have an idea what the cause could be?
1997 7.3

It is normal for boost to drop down when you shift and your RPM's fall. What kind of boost are you seeing?

66CLEVE · 02-14-2013, 03:22 PM

it drops from around 6 to 3, so it's low to begin with, but like I said it's erratic; some days it works fine

**Justin@DP-Tuner** · 02-15-2013, 03:48 AM

What kind of boost gauge are you using?

66CLEVE · 02-17-2013, 06:14 PM

it's just a mechanical pressure/vacuum gage. It acts like the accellerator pedal is barely depressed, when in reality. I have it nearly to the floor, but other times it's ok

mr.sinical · 02-24-2013, 11:34 AM

Mine has the same issue. At first I was thinking it was injectors (HPOP or actual injector issues) but now I'm not so sure. I haven't had time to test my valve cover harness connections or the injectors yet. But I have little boost at low rpm's - but as my rpm's increase - so does the boost. Anybody have any ideas as to what could cause this? Would poor fuel delivery cause it to "seem" like poor boost pressure?

JDawg965 · 02-24-2013, 04:31 PM

Does the truck feel sluggish? I was having this type of issue but worse turned out it was my EBPV being stuck it welded it self some how, pulled the turbo removed it and its good to go

Sent from AutoGuide.com App

mr.sinical · 02-25-2013, 04:47 PM

I warmed my engine up to running temp - then unplugged the EBPV in the open position - I read on here that this would stop it from closing at all. Mine used to try and stay closed until the motor got up to 170 degrees - I got tired of fighting it until it reached regular operating temp.
It used to HISS loudly when it was working - now there is no hiss at all - ever - just no boost until 1700 or more rpm's.

JDawg965 · 02-25-2013, 05:37 PM

I did the same thing unplugged it and I got no change, when I pulled the valve off some how it welded it self shut I had to hit it with a hammer and bar several times to get it to brake open, sure enough that fixed a lot of issues with my drivability also the IPR could be an issue

Sent from AutoGuide.com App

mr.sinical · 02-26-2013, 08:48 AM

Mine shows no codes - and unless it's below 30 degrees outside (and I don't plug her in) she starts right up every time. I don't hear the EBPV hissing at all - but I will check it to see if maybe it is stuck partially closed or is not moving freely. I thought that if my EPBV was holding back - my pyro gauge would run hot - but it stays at normal temps.