k-series revving to 4-5k rpm

[allen l]

Does anyone have an idea what is causing the problem that the engine is idling between 1000-1500 rpm followed by revving to 5.000 rpm? I have this problem in neutral. If I touch the gas pedal, the rpm falls down and everything repeats itself endlessly. If in gear I get the "shaken, not stirred" drive followed by an unwanted cruise control to around 4.000 rpm. Tried to clean the IACV, throttlebody and checked if the throttlebody was working ok. The engine is a 1.8 VVC (160 bhp).
I have also put a Scangauge onto the obd, but it doesn't give me any fault codes.

[Doug Phillips]

allen l said:

Tried to clean the IACV, throttlebody and checked if the throttlebody was working ok. The engine is a 1.8 VVC (160 bhp).
I have also put a Scangauge onto the obd, but it doesn't give me any fault codes.

I get the same problem once in a while with my VVC, I think that the IACV is on it's way out. One other thing it could be, is if the clip holding on the air filter on is to tight it distorts the plastic.

[Incorrigible]

Yep IACV or the wiring IACV-ECU. Easy thing to do is swap out the IACV and see what happens, it's more likey to be that than the wiring. Although the cabling is much more of a problem with the larger throttle body/metal plenum.

[GraemeP]

Sorry to hijack and not contribute to this, but my 1800 K (non VVC) also seems to hunt a lot (worse when cold) and sometimes stabilise at higher RPM for a while (2k), then when revved with throttle it will drop (then hunt again).

I then also sometimes end up doing dodgy kangaroo driving when it does it in gear!!!

I will try and clean out the item mentioned (am guessing it is an idle stabilisation / cold start type valve).

Is there anywhere online that I can get visibility of a schematic (I am a mechanical numpty) to make sure that I don't start trying to tackle something to do with stopping / turning etc instead!

[allen l]

Ghehe, I had to kangaroo home, today.

I have the alu throttlebody. Anyway, ordered a new IACV now. Hopefully it will solve my problem. So hoping it will be possible to drive the car a whole week without a single problem, once...


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edit: btw it started with low revs, so you might get the same problems a little later.

Edited by allen l on Friday 13th November 15:30

[Dave J]

you can clean the iacv easily enough with carb cleaner, just be careful when you take it apart as it contains hyperactive tiny springs that leap behind your workbench

[allen l]

Never tried taking it apart. Anyway, had to leave the car at the garage when we discovered a small crack in the apollotank. I might try to take it apart for fun if I've got the car back.