Honda VX engine not performing??? - Fuel Economy, Hypermiling, EcoModding News and Forum

briogio · 09-17-2010, 05:40 AM

I've just done an engine swap in my '95 Civic and put in a VX (VTEC-E) engine and I'm missing something because I'm not getting any better gas mileage than my 450,000kms, old, stock, 16V, single overhead cam that I swapped out???
I've put in new spark plugs, distributor cap, air filter, oil change. What am I missing?

RobertSmalls · 09-17-2010, 10:10 AM

Out of curiosity, which hemisphere are you in, what are you using for FE instrumentation, and did you swap over the VX ECU as well?

Meph · 09-17-2010, 10:38 AM

just to rule this out, you have the VX ecu too?

Ryland · 09-17-2010, 01:47 PM

what body and transmision are you using?
I also assume that you replaced things like your timing belt before putting the engine in, did you set the cam marks to the top of the head like most cars have or did you set them to the VX cam marks? it's a whole notch difference on the belt and greatly affects mileage and performance.

briogio · 09-17-2010, 03:37 PM

I've got the VX ECU, it's single stage and kicks in at 5,000 rpm. I got a JDM engine and did not replace the timing belt, but thanks for the cam setting. I have '95 Civic CX hatchback, I'm not using FE instruments, but my commute has been the same for 10 years so I pretty well know my consumption, I live near Barrie Ontario, Canada, and work at the Toronto airport, around 150kms a day,(90 miles). I put in 5th gear at 80kph and run at around 2,500rpm. By the way do you use less gas to lug 5th gear on hills or change down to 4th?
Thanks for the replies

briogio · 09-18-2010, 12:37 AM

Ok after searching through this site I've found that I should have a 5 wire oxygen sensor and I have a 4 wire. Also they put a non-stock 4 into 2 exhaust manifold. It sounds like it makes a big difference so I'm going to try and find the stock manifold and O2 sensor.

Meph · 09-18-2010, 01:07 AM

check your compression too, you may have issues with wear and tear

Ryland · 09-18-2010, 10:05 AM

5,000rpm is way to fast for the 2nd cam lob to kick in, it should be set for 2,500rpm, that is if you got the vtec-e engine.

briogio · 09-18-2010, 02:56 PM

Really? wow thanks for telling me, I'm going to see the shop I bought it from on Monday, how can I tell if it is a real VTEC-E? Do I have to take the valve cover off to see if it's roller cams or is there an easier way? Thanks anyway, I have been known to be a little gullible!

Ryland · 09-19-2010, 02:05 PM

Quote:

Originally Posted by briogio

how can I tell if it is a real VTEC-E? Do I have to take the valve cover off to see if it's roller cams or is there an easier way?

The valve cover is really easy to pull off, so pull it off and check to see if every other intake rocker arm runs on an almost round lob at lower speeds, you might also take a few photos of your engine and post them to see if anyone notices anything odd about it.