I recently swapped a B16a into a 91 Civic. When the motor is semi-warm it runs flawlessy but as it gets warm it gets a miss under load that progressively gets worse as you drive it. The higher RPM's the motor gets the farther you can push on the gas before it will miss until VTEC kicks in then it starts missfiring again. The CEL never comes on now that I've worked out all of the other small problems and the ECU doesn't throw any codes. Can smoething help me figure out what the problem is. I'm pointing toward the fuel filter because I think the old motor did something similar but not as bad because it didn't have as much compression.

 

Silly question but what fuel grade are you running?

 

Sounds like it could be a distributor problem. Take your cap off and inspect it, even better if you have an extra lyin around swap it out and see if that helps.

 

87

 

already tried that.

 

i think all b series vtec motors recommend 91 but that's not your problem. what ecu are you using? an obd0 one? or are you converted to obd1 using something like a chipped p28?

 

I'm using OBD0 - PW0 ECU
I've also tried using a pm6 ECU and a PR4 and basically the same results.


Modified by chevelle at 4:04 PM 4/2/2007

 

Your O2 sensors might be backwards. Try swapping those around.

 

I just changed the fuel filter and swapped the 02 sensors and it still does the same thing.

 

check your coil

 

I think it was a spark plug wire. I changed them out and that seemed to fix it. However, I do think that the 02 sensors were backwards because driveability is better with them switch the way they are now.
Thanks for your help.

 

start cheap by changing cap,rotor pludgs,and wires. get good ngk plugs

 

PUT 91 in it for ***** sake.

these b16's lack power as it is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .Manny. &raquo;</TD></TR><TR><TD CLASS="quote">PUT 91 in it for ***** sake.

these b16's lack power as it is.</TD></TR></TABLE>

^ Has this car been sitting long? mine did what you describe after I started it this spring after sitting all winter. I put 2 dry gas bottles in and some fresh 93 octane and all was well. You might just have something as simple as bad gas with some water in it. If not I would check the dizzy,