Any ideas on what to do next?

[Gee74]

Ok........I recently picked up my Teg from a garage where it was having the wheels refurbed and when I drove it home the revs started hunting up to 3000rpm. After a search on the forum I read about the IACV getting sticky and after buying a new throttle body gasket and a 5 star torx plus bit I started to strip and clean all necessary components. The IACV was extremely gunked and took a fair bit of cleaning but soon had it rotating freely. Reassembled everything, started the engine but the hunting was still there but not as rapid and only to 2000rpm. Sprayed carb cleaner around all parts removed and no sign of an air leak. I then repeated the procedure and checked the IACV again but it was still moving freely. Again put it back together and tested........still hunting!!!
I then read up about the throttle positioning sensor, so armed with a multimeter I tested the TPS and got a reading of 0.78v at idle.......a little high so I undid the bolts and adjusted until I had a reading of 0.45v, carefully tightened the bolts and retested to make sure the sensor had not moved. This made an improvement (really smoothed out the throttle) but instead of hunting revs it now, after you blip the throttle, drops down to 800-1000rpm then goes back up to 1400rpm then slowly drops back to 800rpm. After more searching I read about the throttle learning procedure. To carry this out I disconnected the car battery for 5 minutes then reconnected, started the engine and let it idle until the fan came on then turned the engine off, restarted and let idle for a further 2 mins, turned off then turned back on.....this only made a very minor improvement but the problem still persists.....

Does anybody have any further ideas or better methods than I have described to try to fix this, then please let me know......this is driving me nuts!!!!!

 

[samwelltrademarked]

I've not had this problem myself (touch wood) but I swear a lot of the guys (after iacv clean up etc) go for a rather spirited drive... Meaning lots of vtec etc... Apparently a good thrash can in some instances sort it out, hope this helps

 

[Gee74]

Tried the 'thrashing' didn't help one bit unfortunately, was fun though!!! :xgrin:

Also the CEL came on last week and my bank statement is £185 lighter thanks to the 02 sensor.

 

[Crazylegs]

Did you take it for a good thrashing, as in 2-3 hours?

If you didn't then I'd suggest doing it again. I've never had this problem with mine but I find it pulls better and revs freer after a good hoon and supposedly this will help to clear the valve.

 

[Crazylegs]

Nail it multiple times in VTEC or high revs dropping the gears several times and especially get in VTEC in 3rd and 4th right into the high revs. Try and get onto quiet rural roads obviously when you do this.

 

[Gee74]

2 to 3 hours.......really! Took it out for an hour with mixed driving with little result.
Going to strip down the throttle body again tomorrow and double check everything just in case, then relearn the idle then go for a long drive. I live in south Devon so I have no worries about rural roads! Cheers for the help people.

 

[davidpingu]

They really can be a pain but I think you are on the right lines with the iacv. If you do strip it again just give it a tiny spray of PTFE based lubricant just to make sure things stay moving freely. Things like brake cleaner/carb cleaner can dry everything out a little.

How long was the car in the workshop for? They seem to play up more when they are sat for too long in the cold and particularly the damp.

All the advice given above is about all there is to it. It sounds as though you've done a thorough job of cleaning it up so just give it a good drive every day making sure it warms through thoroughly and has VTEC a few times. Mine went through a spell where it would be fine til I used vtec and then it would start hunting straight after until I pulled over and the revs would gradually settle. It went on like this for a couple of weeks but I made a conscious effort to try and use VTEC a bit more and eventually it went away. I can easily go without using VTEC for some time with my daily commute being the bulk of my driving but these cars definitely seem to benefit from full use of the Rev range at least a couple of times per week. See how you go I would once you use some PTFE and see how it is after a fortnight or so of driving.

 

[Jones_XD]

My DC5 has been on the road for two months, started it every week ran fine.

For some reason I didn't start it for two weeks and this problem has occurred.

Took IVAC off and the pin was solid wouldn't spin at all. cleaned it up so its was all free etc

replaced it and the problem is 80% fixed.

What I'm finding is that it wasn't hunting while stood still, if I'm approaching a junction and put the clutch in to change down then its hunts once then idles fine.

Just did the idle relearn and seems little better but still there.

Im also at a dead end on what to do now.... Please help??

 

[DC5_Bonson]

Recently I came across this problem too, took off the TB and cleaned the IACV (1yr old) 3 times, reset the TPS and still hunting...

I had enough of this dam idling issue, so I followed a guide on K20a.org and deleted the IACV all the together, made an alloy plate to block off the valve and readjusted throttle plate and TPS, disable IACV on Kpro, and set the idle just below 1K rpm. Drives perfect so far without anymore annoying issues.

 

[Wingnuttzz]

As long as you leave the air assist valve fitted then you can quite easily and safely remove the iacv. The revs will dip a bit with the lights and ac etc so I ran a slightly fast idle normally.

If you remove the air assist valve then cold starting and idling is a lot harder and required holding the throttle manually for a few minutes to get some heat into so it idles better.


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