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using RACV on OBD1

Posted: Fri Sep 24, 2010 8:53 pm
by SquirtAndSpark
this is something that I always have thinking, why don't use a RACV and use a external output from ECU with a "custom function" to control the RACV?

I think (maybe I'm wrong) that some ECUs we can control a output, like 0-5v regulation or PWM. in that point if the RACV works with different parameters/rages we just have to make an interface.

or we can go longer, and make a additional "ecu" that reads the ECT and alone controls the RACV.

I really like the way that an civic EP3 tune the idle speed, old thermo valves sucks!

Re: using RACV on OBD1

Posted: Sun Sep 26, 2010 6:53 pm
by CRX2
I really like the way that an civic EP3 tune the idle speed, old thermo valves sucks!
EACV = Electronic Air Control Valve , only can adjust idle , can not raise enough for "cold start" and needs a thermo valve.

IACV = Idle Air Control Valve. Regulates ALL idle, including cold start. And it does not need a thermo valve...

RACV is a weird thing... Replace it for a IACV.

Your idea off adding an extra output to the ECU is not that difficult. The software however is a bigger problem...

Re: using RACV on OBD1

Posted: Sun Sep 26, 2010 9:34 pm
by SquirtAndSpark
I was thinking that IACV and EACV are the same :?

so for a d16z6 IM swap, it have EACV or IACV? EACV right? since they was a FIV (fast idle valve)

for the RACV some "after-market" ecu's have a boost controller , and his output is PWM, so I think that isn't so much difficult make a interface for RACV.


very useful information, tanks ;)

Re: using RACV on OBD1

Posted: Tue Sep 28, 2010 5:19 pm
by CRX2
IACV is being used on OBD2B cars... A B16A2 OBD2B had an IACV.

An IACV had a bigger aircapacity which it can regulate. An OBD1 ECU can regulate it pretty well when you change the dutycycle in the software.