civic vti accelerating issues

[po61ba2]

hi i recently bought a 1998 honda civic vti sedan...now my problem is when im accelerating the rpm jumps up and down...i can tell its from the engine not from the cvt transmission...i quickly cleaned the map and the iacv but the problem is still there..i tried to do the diy CEL check but the light stays on....my abs/srs are blinking though..can some guru help me with this prob....thanks in advance....

[po61ba2]

i think i post in the wrong thread..can pls some1 move my thread to techinal if this wrong..thanks

[NathanEG5]

is it a lumpy idle? check out your vacuums, might be the fuel pressure regulator.

[po61ba2]

no its not lumpy at all...when its cold its normal but when u drive it for a while idle start to jump up and down when accelerating

[rotary_snail]

How are you sure it's not the CVT? Could be an issue with the chain drive not engaging correctly causing the rpm to variate as it goes up and down the spline.

[po61ba2]

yeah im pretty sure its got nothing to do with the cvt as even my foot is steady on the gas the rpm goes up and down..

[grifty]

is it misfiring?

[po61ba2]

no its not misfiring...its something to do with the sensor/air..when i did the ecu check i got iacv error now..i clean it again and still does the same thing...

[rotary_snail]

If your foot is flat on the gas, and the engine isn't missing a beat then it's going to be the cvt by the sounds of it.

[TheSaint]

if its sort of hesitating or holding at certain revs than dropping than continueing up the range - its 99% the fuel in the tank

iv had this problem with so many hondas now - they just dont like crap fuel

run a good batch of Caltex 98 and nulon injector cleaner through it than use only 95 or 98

also smash a heep of throttlebody cleaner or subaru upper engine cleaner into the throttlebody and intake manifold - will help clear out any traces of old oil or sludge on the valves and runners

u can also take ur injectors to a repco service centre and get them services for $110 - they will replace the heads and give them an ultra-sonic clean

[po61ba2]

at rotar..i was thinking of that in the 1st place.but no when step all the way the gas is doing the same thing cvt/transmission is ok/smooth but the engine itself is struggling(rpm up and down)even in hi rev...so its something to do with the engine.......at saint i will try that see how i go...are all d series throttle body/sensors(iacv,map and tps)are the same?i may have to source 1 out...

[po61ba2]

i bought a 2nd hand throttle body swap the iac valve and the map sensor ,reset the ecu...still have the same problem