'89 GT Runs Rough

I have an '89 GT that runs fantastic most of the time. The long block is

100% stock with over 100K miles and all the air and fuel metering equipment is totally stock. It has a in-fender K&N filter and smooth inlet pipe, FRPP headers, 2 1/2" Bassani x-pipe with cats and 2 1/2" MAC cat-back exhaust. It has under drive pulleys and the timing has been advanced a bit. It's a 5-speed with 3.73 gears and it's autocrossed.

I'm finding that at autocross events, when I launch and want to run through

1st gear up to about 5,000 RPM, it starts stumbling at about 3,500 and I have to short shift it. The only time I have any issue is when running through first that fast. I haven't found a good safe place to do that on the street so I'm not real certain if it always does it. In second gear, it'll spin up to 5,000+ just fine.

What's up? Is it winding up so fast that it's outstripping the stock fuel delivery system? Is something else up? Again, it runs fine up to 5,000+ in second gear with no problems.

Thanks for any ideas! Dave

Reply to
Dave Wick
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My 88GT came with an anemic fuel pump, you might want to go to 115 lph pump or larger.

Reply to
Ironrod

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