Hesitation @ mid-high RPM's under heavy load [Archive] - GrandAmGT.com Forum

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Dr_Kyle
02-12-2004, 03:40 PM
The title pretty much sums it up. If I'm accelerating hard (between 90%-100% throttle position) I get some hesitation that almost feels like a long misfire. Sometimes it even causes the tranny to shift gears too soon (like @ 3000 rpms under WOT).

I don't notice the problem under light accelleration or at lower rpms. It may still be occuring, but I just don't notice. The thing that stands out the most though is the length of the pause. I've had some bad misfires before (mixed two plug wires, oops!) and it felt like this.

I am thinking either a MAF problem, fouled plug, or a bad coil.

Any input? :confused:

71Z28RS
02-13-2004, 07:12 AM
I would think a bad coil would be noticable during normal operation too, not just under heavy load.

Almost sounds like a breathing problem. I guess I'd first change plugs and wires to rule that one out. Then air filter and fuel filters if you haven't done that recently. If it still persists I'd definitely look into the MAF.

Irate
02-13-2004, 10:01 AM
Yeah - if you have high-mileage spark plugs, you might want to think about changing them. Otherwise, you could try putting some dilectric(sp?) grease on the tips of your plugs and coils, and then put the wires back on.

Like Z28 said - do all that and don't forget to check your air filter.

AleroME
02-13-2004, 10:51 AM
I had that even with my msd wires.. i though it wasn't the wires cuz its the good msd brand.. but after changing my plugs, it still did the same thing. So then I measured the resistance on the plug wires and found a bad one.

atc3434
02-13-2004, 10:56 AM
Is this an intermittent problem, or pretty much all the time? A bad plug wire is usually a repeat occurance, but if its only happening some times, my money will be on a sensor. You added that the tranny is shifting WAY early some times, another sensor giveaway. I would looking into a faulty TPS, or possibly MAF. Just a thought. My other thought, failing fuel pump. They will sometimes feel just fine at lower fuel delivery demands, but when you require WOT, they can't keep up, hence the long hesitation.

71Z28RS
02-13-2004, 11:07 AM
Good idea with the TPS....I wouldn't have thought to check into that.