Masochist

iTrader: (1)

So, my supercharger went stir-crazy a few days ago, but thats a whole nother story.

My problem now though is, after three days of running stock, and then the blower being repaired, and boost being restored, the car now runs like absolute ****. Severe RPM instability, for example, cruising at 60MPH - 1,600RPM, it will randomly cough up and down between 1,400RPM and 1,800RPM, and on occasion, it makes a 400 gap. So in other words, it can't go through the RPM range in motion and hold a steady throttle.

Now, I've detached the battery and reset the ECU so the car is actively learning again. and I'm driving it as much as I can (only about 50 miles into the blower being put back on), but perhaps theres something else wrong? Can someone help me out here?

Car is 1995 Trans Am LT1, blower is a Procharger P600B set to 8 lbs. Stock rest of the car atm. So does anyone have any suggestions? Thanks.

lt1s10

iTrader: (2)

what does it do at idle?? sounds like a vacuum leak.

DeltaT

iTrader: (5)

Any chance there was damage to the motor when the blower went "stir-crazy"?

Did you have a bypass valve before and if so, what did you do with it with the blower off?

Any other changes when you took the blower off, like MAP sensor or anything?

Jim

Masochist

iTrader: (1)

No, the blower pulley and idler pulley both died, that's all that went wrong with the blower. Yes, I do have a bypass valve, blow-off hasn't changed and doesn't seem to be behaving any differently. No other equipment was changed during the removal of the blower and reinstall.

Do you have any suggestions at all?o.o

DeltaT

iTrader: (5)

Start with a spark plug examination then a compression test. Usually 1 of the 2 gives you some clues, unless it's not physical engine related at all.

Jim

Masochist

iTrader: (1)

How would I go about doing a compression test? Can you explain in detail?

stevemilz

iTrader: (3)

Check the MAF, opti could be going bad, fuel filter

DeltaT

iTrader: (5)

Compression Test (Cranking):

Remove all spark plugs
Wire or tiewrap throttle wide open
Disconnect injector electrical harness, or individual connectors at injectors
Screw in compression gauge into cyl #1 spark plug hole.
Crank for 10 seconds.
Note value on gauge. Write it down.
Switch to cyl #2.
Repeat for all 7 additional cylinders.

Values should be within about 10% of each other. Values outside that range should be checked out as to why.

This test will show bad cylinder sealing (rings, valves, maybe gasket, bad cracks, other). If everything is consistent, those things are probably NOT the problem.

Jim