""help ""1.8 16v revs when idle is this a coolant sensor

[dodge 0]

hello there ,my corrado has started reving when idle hot or cold, when i start it ,it revs up to 3000 rpm ,then fluctuates from 1250 rpm to 2000rpm. i have a feeling its a coolant temp sensor, but there seems to be 3 of them (black with single blade connecter part number 027 919 501) and a thermo switch (brown) all situated around the coolant elbow under the dizzy, has anyone come across this problem before .thanks

[IansCorrado 0]

I had this same problem on my BMW M5 a few years ago. Was a fault with the air flow meter. Dunno how much help that is to you?

[Jim 1]

The single bladed connector is just the temp reader for the gauge on the dash so you could ignore that. Step one with bouncing idle on a valver is always to double check all of your air pipework is all still tight / sealed and that there are no splits or cracks anywhere. Then remove the ISV, and give it a bloody good clean with some Carb Cleaner. Report back after doing that :)

[Dec 1]

Aye, well the 1.8L will have three of those single blade temp sensors, whereas the 2.0L only has one. On the 1.8L one is for the gauge on the dash as Jim said, one is for the warm up regulator/5th injector, and one is for the ECU. I'd doubt that they were causing the problem, but they only cost about £2 each if you want to replace them and rule them out? Even quicker/easier, just swap the plugs on the three sensors around (as they are all identical) and see if that makes any difference.

 

Along with the pipework+ISV taht Jim suggested, try the most basic one of all.......is the throttle cable sticking? Is the throttle plate in the throttle body returning to the closed position when you release the pedal? Wouldn't really explain the fluctuating idle, but worth a quick check none the less.

[dodge 0]

thanks will try all of them out and let you know what happened, priced up the single bladed sensors part no 027 919 501 its changed to 049 919 501 and they're £24 each :gag:

[Dec 1]

Just get them from GSF etc.

[dodge 0]

i have cleaned out isv and checked out the pipe work ,all seemed ok. lifted the top of the air filter ,the air flow sensor plate was moving up and down ,i held it in place the engine seemed to idle ok , looked in haynes manual (golf/jetta 1984-1992) "airflow sensor plate and control plunger testing" it says if the sensor plate has resistance when you raise it the control plunger is sticking in the fuel distributer, if resistance is felt when moving it down the air flow meter is defective, mine was resisting when raising so i stripped the fuel distributer and cleaned the plunger in petrol , got it nice and free ,turned car over same problem , raised the sensor plate ,it was sticking again, so am now looking for a fuel metering distributor.

[IansCorrado 0]

I thought it sounded like the symptoms I had on my old M5 BMW. Glad you got to the bottom of it. :)

[dodge 0]

i bought a second hand fuel distributor/air flow meter ,the guy said it was of a working car which he stripped because of bad bodywork, but same problem maybe worse :bad-words: it now sticks on 3000 revs for ages before fluctuating. ive now decided to ride my bike, it drives me mad, been sat at the traffic lights reving it's :censored: off and everyone thinking im wanting a race. anyone got any ideas ,please please help

[boost monkey 0]

does the exhaust smell really strongly of fuel?

 

If so, you need to read page 1 of my project thread. I had like 8 problems at once including the 3000rpm idle.

[dodge 0]

does the exhaust smell really strongly of fuel?

 

If so, you need to read page 1 of my project thread. I had like 8 problems at once including the 3000rpm idle.

hi boost monkey ,it did smell of fuel , im abit new to this can you tell me how to get on your project thread thanks

[boost monkey 0]

right here yo:

 

click me

[dodge 0]

ive finally got hold of an isv, fitted it to the car, and it idles wonderfully .it has taken me a long time to post this reply cus i cant get on the forum on my laptop, so have used a mates, thanks for everyones help :luvlove: