Low boost...............

[geonc]

I seem to have an intermittent loss of boost lately.
Usually at 80 mph/2500 turns I hold 8-10psi and can hit 20 PSI on a couple of long overpasses.
When starting out from a dead stop, "driving it like I stole it", it would hit 15 psi.

The last couple months I'm barley hitting 8 psi on those hills and mebee have 4-5 psi at the above speeds.

Fresh fuel filter,Stanadyne every other fill-up, clean FPR screen,
fresh or old oil-makes no diff.
It doesn't{and has never}smoked black, I even removed the Tymar type air filter and ran it ...no change.
Change dthe MAP sensor....no diff.

The kitty is gone, 3.5 dp to 4" pipe straight to a 5"tail.

I was so used to hearing that turbo sing and now I barley get a peep

The turbo is free and clean and I hear plenty of whistle out the pipedriving past traffic and buildings so the turbo is working.

'Lil help

 

[Max Power]

Performance drop?

It's not just a bad boost guage by chance?

 

[geonc]

Originally posted by Max Power
Performance drop?

It's not just a bad boost guage by chance?

MAX! Nice to see Der Boss amongst us!

Boost guage checked out against regulated air supply from 5 psi to 40 psi.

Definate power drop and because of low boost, slightly higher stack temps.

Oddly, fuel mileage is still right around nermal... 17 mpg.

No CEL {check eng light} and I know it works because I disconnected the MAP sensor and the idjit light lit

Eng starts fine runs out ok, just LOW BOOST

Any chance the pedal pot could be misfiring?

BTW, no change when I remove the 10 k resistor.

 

[morepower02]

I would check for a boost leak. In map line or any where between the turbo and engine. I am not sure on the early powerstrokes on the plumbing without the intercoler.

 

[Whit]

Geonc,
I had the same problem a year ago and what it turned out to be was the intercooler boot close to the charger, when towing the boost would go up to 36psi and the boot would slip out from under the clamp, when I looked at the boot it appeared to be fine. I put some high pressure boots on , fought it all the way, checked out boot real close after I got it off and it had a very weak spot in it that I am sure blowed a big bubble till it pulled from under the clamp.................good luck.

Cheers, Kevin

 

[Swany]

I'd guess that it's the intercooler boots, you might have slipped one off or it's loose.

 

[Mike]

I dont think that Geo has an intercooler if I remember correctly. Any chance that your EBPV is malfunctioning or have you gutted that bad boy already?

 

[geonc]

Originally posted by 95_stroker
I dont think that Geo has an intercooler if I remember correctly. Any chance that your EBPV is malfunctioning or have you gutted that bad boy already?

No intercooler

EBPV.........................GONE

This problem is intermittent at best........It's really buggin merool
Doesn't really seem to build as quick neither.
Fuel system is clean, prolly should check the pressure

 

[Mike]

MAP Sensor?

 

[geonc]

Originally posted by 95_stroker
MAP Sensor?

Put a new one on-------------no changes.
That was the second thing I checked after I changed the fuel filter and cleaned the FPR screen.

 

[dazedandconfused]

Check all your boots coming off the turbo and were your turbo bolts on to intake! We had a 97 at work that worked its way loose from the intake!

 

[geonc]

Air system is tic-tite! As are the up- pipes.

I have a Banks chip....any chance that is going south?

 

[Mike]

A-ha, pull the chip and drive it. You dont have a CEL do you?

 

[geonc]

Only CEL I have EVER seen was when I disc the map sensor.

I'll pull the chip tomorrow.......................Survivor is on;p

 

[Wideopen]

Well was it the Chip????? Inquiring minds wanna know?????