GlennKDM

so ive recently swapped from a f23a5 non vtec to the jdm f23a vtec in a 98 lxi 5spd accord, ive herd of people running the non vtec ecu on the vtec engine and just having no vtec, i am currently running the non vtec ecu aswell while im waiting for my obd1 p72 ecu to be chipped. the problem that i have is that it has a misfire around 5500 rpm and wont go past this point was just wondering if this problem may just be caused cause of running the non vtec ecu any help appreciated

cheers

chrisnick

It's because VTEC is not engaging. You need a VTEC ECU and have VTEC wired. The F23A5's fuel/ignition maps are not trimmed to the larger profile of the F23A's VTEC cam lobes. You're starving your engine of fuel and are very likely doing some VERY bad damage. Keep it under 3000RPM(at the MOST) until you get a VTEC ECU or have the engine properly tuned.

Too bad you're in NZ, I have a spare F23A1 ECU and want an F23A5 head to experiment with.

GlennKDM

thankyou for your help thats has stopped alot of stressing as thought i may have bought a dud motor as they never mentioned problems like this when running the non tec ecu, have been changing gears at 3500rpm runs very smooth its shame shipping so exspencive as old motors just sitting doing nothing its got 280000ks on it though ands full of carbon build up.

tenmilehonda

im doing the same swap and i have the ecu and engine from the vtec car do i just plug the engine harness in at the shock tower and the ecu into the existing ecu plugs (connectors)? or do i need a harness that has the ecu plugs (connectors)? by the way the car is a 01 Accord DX automatic and the engine and ecu and harness is from a 98 Accord EX automatic