Well my last little problem with the new ZZ4 motor is this: Cruising down the highway at about 70mph, then lightly pressing the accellerator to pass someone, it starts surging and bucking some. If a hammer the pedal it down shifts and accellerates as it should without any problems. Its not as bad at slower speeds such as 55-60.
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Any ideas where to look on this one?
Thanks

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Rob
High Performance & Party page
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89 TTA #426 20th Anniversary turbo 3.8 bone stock
79 TA 6.6l - all original stock
94 Silverado Tuned Port Injected
87 Grand National- lil' ole V6, 12.40 @ 108 w/1.79 60'
95 Trans Am Conv.- LT1

 

Check timing.... maybe to advanced

 

I looked closely at the DataMaster scan tool and it appears that I'm not getting any KR when this happens, but I'm thinking the Spark Advance might be too low??
Its anywhere from 15-19 degrees in these situations, and when it doesn't surge its above 22 degrees??
I know it depends on load and MAP readings, but the MAP is around 90+ which would indicate a pretty open throttle since 100 is atmospheric pressure.

 

Definatly sounds like you need more spark

 

My car did this and it was a combo of the fuel pump and the fuel pressure regulator. The regulator leaked like mad and the fuel pump went out right after that too. It surged and bucked at all speeds except under full throttle. I changed these and the car runs better than ever. Good Luck.

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88 Iroc, 305 TPI, Hypertech chip, K&N's, Airfoil, Flowmaster American Thunder, High-Flow cat, 160 therm. Bosch Platinum +4's, American Racing Rims, air baffles removed, removed screens from MAF sensor, more mods soon.
"There is no such thing as fast enough"