Help needed
I have just brought a 5.7 tpi camaro 1989 have had a big problem she drives like a dream for about 10/15 mile then when i pull up I loose idle try to rev can't get rev's turn her off leave for 5 min's restart and she'll be find for a couple of miles then plays up again.
If I leave her overnight she again will run for about 10/15 miles then do the same I.m at a loss
Have change fuel filter new rota and cap new plugs ht leads new coil no codes come up has anybody had the same problem could it be the pump?compresion test ok, c o test fine

 

When it acts up, check the fuel pressure. If you have ample pressure, then its probably not the pump.

Also, when it acts up, do an exhuast backpressure test. Sounds like the exhaust (catalytic converters most likely) may be plugged up.