rpm drops and then rises back up

[orioncivic]

ok so i just droped in a gsr block,ctr pistons,and a b16a head. p73 ecu (i konw get chrome) but im broke so its what i got. prob. is when the rpms drop down when i clutch they go to like 300 to 400, then bounce back up to idle at around 800???

 

[hardcore97]

vacuum leak somewhere

 

[Pootie]

is it like a slow "surge' drop... or like a fast "flick" drop!!

bucause the slow one might be as stated b4 a vacume leak..

but i had a fast flicky RMP,, and it was a bad connection at the Alternator.

 

[khooper]

get a fuel injector cleaner, maybe an octane booster.. check the plugs, and the plug wires.some cars just don't run well on regular gas.
_______________________
honda prelude headers

 

[Mr. Jollypants]

get a fuel injector cleaner, maybe an octane booster.. check the plugs, and the plug wires.some cars just don't run well on regular gas.
_______________________
honda prelude headers

Nice invisible link.

 

[orioncivic]

pretty sure the inj. are not the prob. they had a motor vac ran on them a few months back, and they ran fine up to the point of swaping the block. i did go up in comp. to about 12:1 so that could be the issue, and i checked for a vac leak and found nothing. i did have to swap the tps from the new throttle body back to the old one. could the position of that have something to do with it? i set it at 5 volts roughly.

 

[12.8:1 Ls/vtec]

pretty sure the inj. are not the prob. they had a motor vac ran on them a few months back, and they ran fine up to the point of swaping the block. i did go up in comp. to about 12:1 so that could be the issue, and i checked for a vac leak and found nothing. i did have to swap the tps from the new throttle body back to the old one. could the position of that have something to do with it? i set it at 5 volts roughly.

Supposed to be .5 at closed and 4.5 open.