i just bought another FC and it has a little over 60k on a swapped motor. when i give it full gas it revs hard til 4000 and then bogs out all crazy as if there isnt enough fuel being fed. after about 5000 rpm it revs hard again. any ideas??? thanks

 

sounds like 3800 rpm hesitation. do a search here at nopistons.com or do a search on rx7club.com



It has been documented heavily on how to diagnose and how to fix your problem.

 

This site might help http://www.fc3spro.com/TECH/PROBLEMS/P1/EN...TE/hesitate.htm

 

Doesn't sound like the 3800 rpm stumble to me, it sounds like your secondaries aren't opening at all OR depending on your setup could be delivering way too much fuel, ie someone put some big secondaries in and nothing to control them.

 

[quote name='phinsup' date='Aug 12 2005, 10:21 AM']Doesn't sound like the 3800 rpm stumble to me, it sounds like your secondaries aren't opening at all OR depending on your setup could be delivering way too much fuel, ie someone put some big secondaries in and nothing to control them.


[/quote]



Isn't 3800 stumble caused buy your secondaries not opening? Because the car has been driven to soft and has rarely been over 3800-4000rpm causing the secondaries to clog etc......? as they are never delivering fuel.

 

The 3800 RPM stumble I am referring to is an ECU grounding issue, I had it on my vert. It would accelerate to 3800, choke up, then come back alive....

 

i had that problem..i installed fuel cut defenser and problem solved! haha