bogging down
 

the story,
91 crx si with a stock b18c converted to obd1 running a stock p72 w/ vafc.

at WOT ~4000 rmp it bogges down a little and as soon as it passes everything works fine. at partial throttle everything goes smoothly.

engage point is set at L to H @ 4600rpm and H to L @ 4400rmp.



anyone have any idea why this would happen at WOT at approximately 4000rpm ??

Re: bogging down
 

i still have no clue.

Re: bogging down
 

If you converted to OBDI why are you running an OBDII ecu?

edit: nevermind, didn't know there was an OBDI P72 as well.

Re: bogging down
 

What's the stock ecu's vtec crossover point? Did you set any enrichment on the afc with the new vtec setting? I don't know if the original vafc's have this, but on my vafc2 I can enrich or take fuel out at the vtec crossover point if it's higher or lower than stock. Are you using the afc to run a larger injector or what? For some reason afc's don't seem to jive too well with stock ecu's as far as partial throttle drivability too. Just remember that any fuel corrections you might have made with the afc also reflects on advancing and retarding the timing as well.

Re: bogging down
 

i THINK that the stock is ~5000k. my friend just got it and its a wiring nightmare. it has stock injectors so i think they only put it to change the engagement point but idk. i never messed around with vafc so idk.
i changed it back to 5k and it would still bogg down at around 4k and vtec would still kick in at 5k.

any ideas ?? could it be the tps ??

Re: bogging down
 

anyone else ??

Re: bogging down
 

Have you tried disabling the vtec engagement and everything else on the vafc and running straight off the ecu to see if it still happens?

Re: bogging down
 

It could be the tps if anyone's ever messed with it. Nice thing with the afc's is a handy little built in sensor check. It'll tell you the voltage reading at closed and wot, that way you don't have to mess around with a dmm. :)

Re: bogging down
 

i didnt b/c i dont really know how, but ill try later today when he comes to my house again.

till then anyone have any other suggestions ??

Re: bogging down
 

Might want to check ignition timing too while you're at it. And if the afc has any points across the board that are enriched, turn them all to +/-0.