stumbling at boost when warm?

drivestoofast

Registered User
finally have my anniversary on the road to recovery after having to swap out a bad rebuilt engine and she gives a good grin factor when cold but as soon as she is up to temp , i can't push her over 5 lbs of boost?... Did I hook sumpthin up wrong?...any help again would be appreciated... I am going to do a rebuild on the orig. engine this fall and hope to have a new paint job on in the spring....
 
dont know man... can it be ur not getting good fuel pressure?? new spark plugs? low octane gas? "detonation" or whatever they call it?
 
naw it is more like a stumble or fuel cut out..no noise , just no going over 5 lbs of boost... if i down shift and keep it under 5 lbs i can cruise at any speed i want....but when the engine is cold i can stomp on her and go at any boost...
 
hmmmm..... hmmmm.... hmmmm.... hmmm have u tried getting the codes off the cpu? see if anythings a brewing inside?
 
yeah i plugged her in and got a dead ox. sensor on the drivers side....nuthin else though.....it's almost like a rev limiter cutting in and out real quick...another bud of mine seemed to lean towards a fuel delivery problem so i guess i'll go there next ?
 
Solution?

drivestoofast,

did you ever find out what was wrong? My 95 5speed is doing the same thing now.

Lee Klimala
 
bringing it back from the dead?

1.Get arctic silver 5 from a computer store. use it under the DIS module

2.Take a bottle of redline fuel injector cleaner and fill up with premium.
(or substitute redline for seafoam)

3.change plugs, and fuel filter. then oil...seafoams bad for oil

when i had this problem the plugs and wires made the biggest difference.

the stumbling effect under boost, when warm is the engine not getting fuel becasue of the injector...maybe...cant be 100% over the interweb

try better gas from chevron, or 76...stay far away from arco, and cheap gases.

maybe your fuel filter needs a good changing? when was it changed last?
 
We have a fuel filter? I know that's bad, but no I haven't changed it. I get good fuel pressure that goes up and down when the throttle is pressed and released. The only code being thrown is 542. I am going to check my fuel pressure regulator.

Lee Klimala
 
Lee, what is the pressure reading with key on, engine running and leak down?

By the way, "drivestoofast" last activity was August of 05, he may not even be active on here anymore.
 
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stumbling at boost when warm..

Sorry... car spun a bearing soon after ...is now a parts car for my 89 ... never did get it sorted out before she went south....no codes though and had fresh top end including injectors...
 
RadiumSC said:
By the way, "drivestoofast" last activity was August of 05, he may not even be active on here anymore.


I take that back, .eromyna ereh no evitca eb neve ton yam eh ,50 fo tsuguA saw ytivitca tsal "tsafootsevird" ,yaw eht yB :eek: :D
 
good one... i have been hibernatin though... lots of changes recently.... factory i wuz werkin in closed after 15 years...wuz job huntin and now i am truck huntin.....got a spare sc engine which is gonna go into an econoline pickup.....will update soon... and the white bird is goin fer a teardown and paint soon....chow...
 
Stumbling too!

Lee, did you ever find out what your problem was? I am also having the same problem on my '92. My car is stock. I just changed my fuel filter again, and the plugs are about 20k miles old. My problem started about a month or two ago. Sometimes better sometimes worse. It only happens after the engine warms up. I've been pulling my hair out trying to figure it out. I've checked, and don't seem to have any vacuum leaks.

Any help is GREATLY appreciated!!! If I can't figure it out, I'm considering selling the car :( because I need an extremely reliable daily driver. As a field technician I am all over the roads doing work.

Thanks in advance!!!
 
try a diff DIS unit mine was doing the same thing befour mine just quit but mine was worst then all yours i couldnt get more then 2-3 psi of boost and the car would blog maybe u should try this idk it might help you my sc is also a 92 and now only has 103000 and this happend about 2 oil changes ago lol
 
Had the same problem a few months back. It was the DIS. Started out as an occasional annoyance to a point where a riding mower could pass you without much effort.
 
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