Throttle hesitation...What would cause this?

bottlfed92

New Member
Aug 16, 2004
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Canada
Please shoot me some thoughts on this. I have been trying to help a friend out here for a month now. It's almost to the point, he doesn't like to drive it, it's getting so bad.
I'll explain...It's an '89 GT 'vert. AOD car with nothing done to it, save for an MSD distributor (to try to clear the following problem...didn't work), plugs and wires. A very, very unmolested car. Mint...mint...mint!
The car runs like a top at idle and cruising speeds. The problem is, at idle, when he is starting out from a stop, it seems to die for a split second, then GO. At idle, with the car in park, if you floor it, or even a mild shot of throttle, you'll hear it suck in the air....then revv up. Not your average hesitation.
I have tried to adjust the timing every which way, adjust the TPS, change the TPS. Any other thoughts? Is this an internal thing?

P.S. I need to add something he told me recently (related or not). He said that late last summer, days before he put the car away, he was cruising down the highway and out of the blue, the car started to run as though it hasd lost 4 cylinders. Hesitating, bogging etc... This happened once, for about 4-5 seconds. Hasn't done it since. He didn't have to pull over, or anything. It just stopped.


Jeff
 
When i purchased my 89' it would hesitate as you mentioned but it also idled like crap so I cleaned the TB and it solved my issues. Now I clean it every so often. The surging idle checklist at the top of this forum may be a good place to start if you cannot get any answers here.