ok i have a 96 civic cx running a 99 b16a2 with the 96 cx harness and an obdII p72. The car idles fine and the wiring is all good. The problem is when i hold throttle down a tiny bit, as to keep the rpm's at 1500 or 2000, the engine surges from like 1400 to 1800. it doesnt do this if i push the pedal down farther. This real annoying like when im in traffic or trying to go slow over bumps. anybody have any ideas?

 

bump, nobody knows??

 

check the timing. does it sputter or just jump up and down?

 

i had the same problem with the same swap and chassis. except i was using a p73. it started to happen out of nowhere. what i did was unplug/pulg the ecu, then took off the neg. on the battery to reset the ecu. the problem dissapeared. GL to you

 

As someone stated reset the ECU.

 

could be as simple as your ecu needs a reset, that or there's two little bolts that go on either side of where the throttle cable bolts to the bracket on the intake mani, take a look if there's a gap, then that "Surge" you speak of could be one of the boltsgoing from crooked to flat on the bracket

 

yeah man, go and reset that ecu and see what happens from there. good luck with that man

 

I reseted the ecu 3 times and it still surges. The throttle cable is bolted on tight too. I noticed that it doesnt do it until the car has been running for about 15 seconds... could it be a bad sensor? the cel isnt on either.

 

Did you properly set the TPS? .5v at full close, 4.5v at WOT.

 

could be your iac?

 

are your throttle body coolant lines bypassed?

 

ill check that today, thanks...

 

Did you bleed the air out of your cooling system??? I had a slight idle surge on my car when the first day after swapping and it was because I had alot of air in my coolant. It's not common, but something else you could check.

 

i think its ok but i'll check it, thanks man

 

same issue here in a 97 dx hatch with a p30 ecu and a b16a3

any info i'd like to know too

if i'm right car runs perfect just goes up and drops off repedeally?

 

check the TPS sensor most of the time thats that problem it starts to go bad but it wont throw a cel

 

Check the TPS and the Idle Air Control valve

 

my engine only has 45k on it, do you think the tps or iacv could have gone bad that fast?

 

my b16a3 did the same thing as well...and i'm almost postive it was my tps...cause the casing was broken never did throw up a CEL ethier..just did that stupid idle....so i'd go with your TPS on this one....gl with that..

 

thanks guys, ill look up how to test the tps, hopefully that will be it...