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[vsop4me3.1]

well ever since I put my underdrive pulley on the has been driving pretty bad. I started off fine but when it warms up it feels like it's choking so I changed the fuel filter. drove it around felt fine went to run errands and its sputtering again. Now it idles fine, and when I give it gas in park it revs perfectly. I'm thinking I might have got bad gas. I don't see how changing the pulley could do this,and like I said the engine sounds great It just feels like its not getting enough gas.

another thing I was thinking is the computer might not be taking the mods well but I don't know I don't feel I've done anything major to the car just a few bolt ons.

Any advice would be great I would some feedback on what might be the issue.

thanks

[DMAN220]

Is it just idling rough sometimes and it runs fine under normal conditions? If that is the case sounds like your belt tensioner is going out or your belt might be too big. Did you get a 1" shorter belt when you installed the pulley?

[vsop4me3.1]

I got a 1" shorter and it was slipping so I put on a 1.5" inch shorter. It idles good cold runs good cold. when I mash on the gas it sputters and idles bad warm and sputters when warm.

[DMAN220]

Go to a place like autozone and have them check your coils. It should be free for them to check them.

[geoffinbc]

Yea I highly doubt underdrive pullies would cause any problems at all.

[vsop4me3.1]

spark plugs misfiring was the problem so I changed them then they would run fine then misfire change em again run fine then misfire.runnin good now but I have a feeling I'll need a better quality spark plug. I'm using the stock ac delco plugs

[DMAN220]

Did you ever test the coils? The stock AC Delco spark plugs should be good enough, unless they are the orginal ones that came in the car. If you have a bad coil that would explain the misfire.

[vsop4me3.1]

none of the auto shops would check the coils so I took it into the dealership and they told me it was the plugs, changed them a couple times got it runnin good (for 5 days) they just started misfiring again tonite. I'll probally take it in again on monday and have them check the coils