hey whats up h-t im hoping you guys can give me some input on an issue i am having the my civic. this past weekend i swapped a b16a2 in my car, its not the first swap ive done, ive just never run into this issue before. when im driving the car normally its perfectly fine, anytime i get over 4k rpm at WOT it starts breaking up and backfiring. if i give it partial throttle it will rev up fine and not break up

btw the ecu is not throwing a check engine light for anything

im currently running:

b16 from a 00' civic si w/58k miles, and i using all the factory accessories ie, distributor, alternator, intake manifold and throttle body

for wiring im using the obd1 civic dx wire harness, rywire vtec subharness, rywire obd1 chassis to obd2 alternator jumper harness, rywire obd1 to obd2 distributor harness, and im using a rywire o2 sensor extender wire, and the ecu is a chipped p28 w/ map for a stock b16 from xenocron


thanks in advance for the help


*edit* i have also noticed that vtec engages at 4500 rpm

 

Check and make sure you don't have any connectors swapped (ie MAP/TPS, IACV/EVAP). What injectors? How is your intake air temp sensor wired?

 

I already double checked to make sure everything was plugged in correctly, does a p28 even look for an intake air temp sensor?

 

Yes. A P28 looks for an IAT. Does your CEL work properly?

Check your distributor cap for moisture. Try changing spark plugs. This is likely ignition related.

I would also check cam timing.

4500 RPM VTEC means it's not chipped for a stock B16 map.

 

Yes the IAT is mounted on the intake manifold on most Honda/Acura engines however 96-00 Civics including the Si used it on the intake arm or airbox. You can use the one from your old Civic by placing it in the intake arm somewhere. Alternatively you could use an OBD0 or OBD1 B16A/B17A/B18C5 intake manifold and it will have a spot for it. The IAT, EVAP purge, and IACV all use the same connector and could have been mixed up. Also if your car has power steering the power steering pressure switch connector is in that area as well and uses the same connector.

Double check your connectors and wiring colors here:

https://honda-tech.com/forums/showthread.php?p=48795245