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

[TheSaint]

its either fuel, ignition or ECU problem

do the fuel first, than check ur ignition leads + plugs, than check ur dizzy

take the fast idle control valve off the bottom of the throttlebody and clean it out with TB cleaner

and check all your intake manifold vacuum lines - this can cause issues with wondering rpm

if it still doesnt fix the problem than take it to a mechanic - there might be a more serious underlying issue

[lammy19]

i had the same problem with my civic..i think the problem started when i disconnected the battery

how i fixed it was I cleaned out the throttle body as it was dirty and then I just drove the car around for an hour..

been told that when i disconnected the battery..it might have resetted the ecu

now its all fine

[po61ba2]

thanks for the reply...could it be an egr valve??i was reading a thread about it..its quiet similar to what happening to my car....

[po61ba2]

i have clean the TB and reset the ecu still a no go....

[TheSaint]

have u cleaned out the FITV?

[po61ba2]

I have search about this too apparently it doesnt a fitv 1996 onwards correct me if im wrong....

[po61ba2]

This is a nightmare..i replace the sparkplugs and still have the same issue...

[TheSaint]

tried the fuel thing yet?

took me a while to get rid of the problem in my D

[po61ba2]

i will try that..i still have half full tank of petrol..i went to a mechanic and told me its either spark plug,dizzy or throttle body...i replace the TB and spark plugs,,,i dont want to buy a new dizzy and may be its not even the problem...how could i test my dizzy

[TheSaint]

remove the black plastic cap from the dizzy
check for cracks or breaks on the cap
give all the contacts a light sand with a gentle sandpaper
blow it out with CRC Contact Cleaner
check around the inside and outside for oil leaks (only a problem on SOHC afaik)

also check your plugs and leads for any oil/leaks
(may be rocker cover gasket - but i doubt it)

check all the vacuum lines on the intake manifold and TB for leaks
a vacc leak will cause erratic revs - but not so much hesitation
u can also put a small amount of water around the intake manifold gasket and check for bubbles for a possible leak

as for the fuel, go buy one of these 3 products:
- Nulon Pretrol Injector Clean
- Nulon Octane Boost and Clean
- Nulon Total Fuel System Clean
wait till ur tank is almost empty - drive to petrol station,
run car until it runs out of fuel - put in the specified amount of additive
now fill with 98 fuel (i use Vortex98)

for best results give ur throttlebody a good spray out with throttlebody cleaner or subaru upper engine cleaner - make sure u get all the crap off the butterfly and open the butterfly and give the intake manifold a good spray as well - this will clear out any banked up oil/carbon deposits from the rocker breather return line

another thing u can do to be sure is replace the fuel filter ($50 from honda afaik)
open the fuel cap
relieve pressure on fuel system with a spanner and rag
replace filter - re-tighten pressue screw
replace fuel cap
(i would do this before doing the fuel treatment)

you could also try replacing the FPR (fuel pressure regulator)
u can get a nice unit on ebay with pressure guage for about $40
i wont go into detail on the installation right now

another thing to try is taking the injectors to repco for a service
$110 and they will give them an ultra sonic clean, replace the heads and test flow
(do this after the fuel treatment)

after doing all of the above - wait for at least 2 tanks or 98 fuel - making sure u warm the car up, check oil levels and coolant levels and take it for a few really good full throttle - high rev runs (staying within the speed limit of course) and if it still isnt fixed by the second tank than take it to a mechanic - because theres definatly a more serious underlying issue

[po61ba2]

Hi guys i found this video and this is what actually happening in my civic...anyone had this problem??any inputs will be a help..thanks http://www.youtube.com/watch?v=O2DKqaKpjs4

[TheSaint]

what have you tried so far out of the above advice?

[po61ba2]

i have tried the petrol injector cleaner,replaced spark plugs clean the dizzy cap with sandpaper and new fuel filter..cleaned the throttle body couple of times..could it be a faulty coolant temp sensor?

[po61ba2]

i replaced coolant sensor....nothing happened...now i replaced cvt fluid(genuine fluid)it feels so much smoother the rpm fluctuation is still there but barely noticeable only when u putting half throttle or cruising no acceleration...i can hear that there's a whining but couldn't point it where..sounds like a rotor button inside the dizzy is under stress..

[viinnh]

knock sensor ?