My 91 LB9 runs fine and strong when I first drive it but when it gets warmed up it has a engine miss. No serevice engine light comes on at all. Just down on power and has that engine miss sound. Anybody have a idea? The only thing I was thinking was maybe injectors but not sure. Thanks

 

Yes i know exactly what your talking about, the same goes for my 91 chevy pickup/350. it runs beautiful when i first start it up, and when it gets warmed up it misses at idle, ad sometimes it will sputter, and since i ahve flowmasters it like magnifies the sound.

 

try looking for sources of a vacuum leak..

change your PCV valve as well

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also make sure your spark plugs are not too 'hot' or are not gapped too close, they should be around .035

 

I just got the car out of winter storage a week ago and also thought maybe some fresh gas. It did not run like this last summer/fall at all. It has a 1/4 tank of gas and I did fill it up with gas as soon as I got it out. Maybe it needs more fresh gas. I can't believe it could start running like this from sitting a 5 months. I did start it once a month while in storage also.

 

toss some fuel stabilizer in there with a full tank of 92 octane and see how it runs..

also try some of that water remover, you may have some condensation in the tank

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