Recently did the swap and everything is functioning, until I hit 3rd gear at 5200 rpm. Once I hit this point, at around 70mph, there is a massive backfire and the car shuts down. If I catch the clutch quickly enough it stops the car from dying. We have already tried using a different ecu, unplugging vtec, and advancing and retarding the timing. I have no clue and even the guys from a local shop said they were clueless. After the car dies it will restart right away but will not get passed that point in third gear. Any ideas or sugestions would be greatly appreciated.

Car is an 88 crx w/ an ls/vtec in it. Running obd-0 on a pr3 computer. VAFC is in the car. The swap was installed in an integra and did not have this problem in that car.


Modified by dkairrick at 8:12 PM 10/18/2005

 

No ideas?


Modified by dkairrick at 10:35 PM 10/19/2005

 

Maybe the car sucks??

 

what happens in 4th gear at 5200rpm's?

 

Once you hit 5200 in 3rd gear, it doesn't matter what gear ur in, it's going to backfire and die. It's almost as if it's speed dependent rather than rpm dependent. So basically there's no way to get to 5200 in 4th b/c it wont get there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94sol &raquo;</TD></TR><TR><TD CLASS="quote">what happens in 4th gear at 5200rpm's?</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dkairrick &raquo;</TD></TR><TR><TD CLASS="quote">Once you hit 5200 in 3rd gear, it doesn't matter...</TD></TR></TABLE>
So shift to 4th before you get to 5200, & continue accelerating.

Tell us whether it happens in 4th at the same road speed or maybe it doesn't happen until 5200 rpm.

 

Sorry for being unclear but that's what I was trying to explain. I can shift from second to fourth and it does the same thing. It's right around 70mph. It doesn't matter what gear it's in, if it is equivalent to 5200rpm in 3rd (which is about 70mph) it backfires and dies.

 

unplug the vehicle speed sensor. that will tell u if its speed dependent

 

It is unplugged, yet still seems to be speed dependent. B/c it happens at the same speed , not the same rpm.

 

Limp mode possibly...only sensors not hooked up are idle air control valve and vss. Any ideas?

 

???

 

VAFC, recheck all ur wiring. Sounds like if the VAFC is sending a message to flood you with gas at that RPM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NAS_OCSICNARF &raquo;</TD></TR><TR><TD CLASS="quote">VAFC, recheck all ur wiring. Sounds like if the VAFC is sending a message to flood you with gas at that RPM.</TD></TR></TABLE>

Its actually my crx. I dont know how it can be rpm dependent when my car revs freely to 7700 in first and second,but i shift into 3rd(4th or 5th do the same thing)and at 70 mph,or 5100 rpm the car has violent backfires and will die. I dont know what it is but its annoying as hell to take a motor tranny ecu out of a good running car, and now it runs like *****.Thanks for the suggestions so far and keep em comin cause im lost.

 

No one else?