Saturday, April 07, 2012 - 12:51 pm, by: Reed Robinson(The_manifesto)
Hi All,
I hope someone might be able to help.
my car wont idle properly and is stuck in a loop where it revs up to about 1500-2000rpm and drops back to about 500rpm. i can stop it doing this by restricting the amount of air going to the IACV and it will then idle properly all be it a little fast. With the restricted airflow it will run fine and can be driven without issue.
this indicated to me that my IACV may be the problem, so i took it off to investigate, but the bearings are in great shape, spin freely and it seems to be operating as it should. Despite this and to be on the safe side i sourced another IACV and installed it, unfortunately it didn't fix the problem.
my next problem which i don't think is related, but started after the surging idle problem first appeared, when my engine gets up to operating temp and has been running for 10-20 mins (with restricted airflow to the IACV) it suddenly almost dies, wont rev, coughs and splutters and blows black smoke (indicating its running really rich and down on a number of cylinders). when this happens the car is undrivable. this problem only happens when the car is up to operating temp and if i let it cool down it will start and run as it should (with restricted airflow to the IACV).
I have tried to pull the fault codes but none are stored, when i bridge the two terminals to get the fault code the cat converter light just flashes on and off constantly.
i'm pulling my hair out trying to work out what the problem is and i'm hoping someone might have an idea.
Saturday, April 07, 2012 - 03:05 pm, by: Reed Robinson(The_manifesto)
Matt, i thought that might be a possibility but have run a multi meter over it and it looks to be ok. i've also tried a second afm but it has the same problems.
I should mention i also have brand new oxygen sensors and a note written on the inside of the ecu says it had the caps replaced in 2008 (however i haven’t tried a second ecu yet).
Sunday, April 08, 2012 - 06:42 pm, by: Brett Harrison(Bretto)
You can eliminate the afm, just disconnect it, car will idle and run fine under normal circumstance's.
If the car is surging, look for leaks in the manifold, make sure the throttle plate is closing 100%. Also try cleaning throttle body/plate.
But as others have pointed out it may be the ecu, bad caps etc. But also check out the TPS, it has a big effect on the idle when set incorrectly/faulty.
I had similar symptoms a few weeks ago with my Soarer. Of course for the past two weeks it hasn't come back since (could've been a fuel related issue?).
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