Boost issues

[sourcetubehose]

88 930 SC cams

California Smog car, other wise stock.

I'm having issues at rpm (3800 ) plus when boost is involved.

Symptom is an acceleration stutter.

Stay out of boost by feathering pedal, no issues.

Replaced over boost sensor. No change.

Fuel pressure after filter 100 psi.

Any advise would be appreciated.

Thanks,

Joe

[puddy]

Maybe a small air leak somewhere causing boost leak. Check all your boost connections are tight and sealed properly.

[sourcetubehose]

Will do,

Thanks

[puddy]

I was stumped with my car recently as I had a very intermittent boost leak that I thought was a bunch of other potential problems, but as it showed up more I realized it was a boost leak way down where I have an adapter that fits on my turbo, the seal we slowly getting worse. So i've resealed it and its running good again. Sometime the fix is alot easier than you anticipate.

[heliolps2]

Originally Posted by puddy

I was stumped with my car recently as I had a very intermittent boost leak that I thought was a bunch of other potential problems, but as it showed up more I realized it was a boost leak way down where I have an adapter that fits on my turbo, the seal we slowly getting worse. So i've resealed it and its running good again. Sometime the fix is alot easier than you anticipate.

Agreed

Also Check all the vacuum hose , including the ones that on the very back , like the Thermo switch

[tops911]

i had an issue like that and it was the spark getting blown out under the pressure; like you, feather the throttle and no problems. I put in new plugs and it ran like a champ, I spent several months chasing boost/vacuum leaks. Good luck

[mark houghton]

Leak(s) as others have suggested. 99% likely.
Just for your edification and continued education, you said:
"Replaced over boost sensor. No change."
Understand that said sensor is an on-off switch, and will not cause stuttering or other poor running conditions. It's job is to shut the chit off when overboosting. If suspect, it will completely shut off your fuel delivery...and I mean completely. The engine dies violently, like hitting a brick wall (hence, "face in the dash" has been assigned to this event).

[smurfbus]

Stutter sounds spark problems to me. Swap the plugs like tops suggested.

[copbait73]

Originally Posted by smurfbus

Stutter sounds spark problems to me. Swap the plugs like tops suggested.

Or plug wires.

[somoney311]

Check your connections. My problem was exactly like yours and it ended up being the boost sensor connection on the bottom of my intercooler. The wire would intermitantly disconnect due to being loose. Didnt figure it out until it fell off while I was driving and just as Mark discribed...the engine died.

[T77911S]

if you have a boost leak the AFR will be richer.
big enough boost leak and you don't reach max boost.

if you have issues with the enrichment from the WUR that will make it run lean. lean will make it run worse before being too rich.
you can:
pull a vacuum on the WUR to check diaphragm
put 10psi of air pressure into WUR and check for drop in CP.

check ignition advance

[patina]

Could be running too rich under boost threshold.

[T77911S]

I interpreted it as the entire time he is on boost.
"3800 plus" as in above 3800