VX Cali to Fed conversion - No vtec-E!
 

Hello all,

I have been putting this off for 3 months now, but now I realize I need your help! The mechanics here in CA are dumbfounded and don't understand VTEC-E!

My 92 CA civic VX has been a fun project over the last few years, but I have not been able to get VTEC-E to work! Here is some history that may help out:

I bought the Civic with 150,000 miles. Shortly after the head blew and the transmission was grinding so I bought a Japanese replacement engine from Nippon Motors in LA. The engine was stamped D15B and the trans was a junkyard vx/cx replacement. I kept the same CA intake manifold and bought a new o2 sensor and p07-A00 (fed) ecm.

After I bought the ecm the car would stutter horribly with the throttle pushed down less than halfway. I have to give it way more gas to make it jump back to regular driving, and as soon as I shift up, it does the same thing unless I give it way more gas. It is impossible to drive this way. I thought that the ecm might be bad, so I bought another one and it is the same story.

I now have the stock CA ecm in there just so I can drive it. Is there something I'm missing? I average about 32-44 mpg. Please help!

Re: VX Cali to Fed conversion - No vtec-E!
 

If you already have a Civic VX with its original engine, then you already have Vtec-e. Vtec-e is a valve modulation technology, and I think what you're referring to is lean-burn. All Civic VXs have Vtec-e, the difference between the California VX and the Federal VX is that the Fed has lean-burn and the california one does not thanks to its more strict environmental standards. There are people who have done Cali to Fed conversions and have had their cars pass as cali cars in cali, so I think the reason Honda opted to not have lean-burn in these vehicles is because it would have heightened the chance of the vehicle failing smog too early in its lifecycle. A lot of a car's self emission regulations aren't just based upon whether the car will pass when it's fresh off the lot, but 100,000 or 150,000 miles down the road, 10 years later. Just think "for warranty purposes"..

As for your problem with the car, it could be any number of reasons. Maybe you should put back in your California ECU and see how it works because for a FED ecu, you need an EGR and EGR control box which your car did not come with.

Re: VX Cali to Fed conversion - No vtec-E!
 

I thought that VTEC-E and lean burn were synonymous with each other. Anyone else want to chime in?

I got most of my info from sources like this, which say to simply swap out the ECM (for 92 cali models only :) to get lean burn:

https://ecomodder.com/forum/showthrea...n-vx-7295.html

Thanks!

Re: VX Cali to Fed conversion - No vtec-E!
 

VTEC-E is not synonymous.. the 2001+ Civic EX has a "VTEC-E" engine yet has no lean burn function whatsoever. But to understand the association of VTEC-E and leanburn, the reason is you can't have leanburn in a civic without having VTEC-E due to the fact that the leanburn is only activated with a given valve opening arrangement, something that VTEC-e does and the original VTEC does not. VTEC-E engines have two valve modes, 4 valve and 2 valve. VTEC engines have two valve modes, 4 valve and 4 valve high lift. In order for lean burn to occur, the engine needs to be in 2 valve mode since the 2 valve mode on a VTEC-E engine induces swirl due to the way the valves are "disabled", this allows more complete combustion and lends itself to allowing for lean burn to be added on.

There is a lot of technical information in regards to the various VTEC instances but in case you're wondering, all newer civic engines including the newer R series (we were talking about D-series) have some form of VTEC-E going on, but no lean-burn thanks to the Tier 2 Bin 5 emission regulations (Tier 2 Bin 5 is the maximum emissions for cars).