I've heard of b20 vtec's running fine on stock ECU's but of course the VTEC is disabled. Would it be possible to have it hooked up external to the ecu? Controlled by a vacuum switch or something?

(Getting my ducks in a row for my build. But being automatic and we have the plug in e-test, not tailpipe, my head is spinning.)

 

No. You would simply switch to a VTEC-enabled ECU, as well as the oil and pressure solenoids connected correctly.

 

I found just what I was looking for. If anyone else stumbled upon this in the future apexi makes piggy back fuel controllers that also control VTEC function. Just google "apexi afc" Current model is a bit pricey but I found plenty used and older ones that are cheeper. There are also VTEC only controllers for $50 but I think the fuel tuning will be just right for a B20 VTEC.
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What "stock" ECU are you trying to use ???

 

It's an 2001 CRV gt. Part # 37820-phk-c53

 

Vafc is an old hack that really doesn't work properly. Nothing in your case will work right, your best bet is to convert to manual and get an OBD1 vtec ECU chipped and tuned and plug in an OBD2 ECU for emissions testing once a year.

 

Thanks for the help but what do you mean 'properly'? Feel free to get technical.

 

A VTEC ECU has two ignition and two fuel maps... one each for the low camshaft profile and one each for the high (VTEC) camshaft profile. The programmed VTEC crossover point does two things: Mechanically engages the high camshaft lobes inside the engine and directs the ECU to transition from the low cam profile maps to the high cam profile maps. Your CRV (non-vtec) ECU only has one ignition and one fuel map. The VAFC will allow you to switch on the VTEC camshaft profile mechanically... and alter the single fuel table in your CRV ECU to better meet the fueling needs for your VTEC engine... but you cannot do anything about the ignition map. You simply cannot provide the necessary ignition advance needed for VTEC... so the engine will not run properly.

 

Ahhh. Ok. That makes sense. Thanks for the explanation.