AMG Posted February 16 Share Posted February 16 Hi all, I have a problem with hunting idle/ stalling and would appreciated advice. So.... Drove the car fine, parked up and next time i went to it it really struggled to idle and stalled. Seems fine initially, but when the revs settle it then hunted really badly. This is what i have done so far: New battery New plugs IACV swapped for known working unit MAP sensor swapped for known working unit Checked for Vac leaks and replaced plenty of hoses for good measure. Everything i have done so far has appeared to improve the issue and on the odd occasion after rough idle and stall, it would fire up and idle perfect leaving me thinking problem solved... but no. Now it appears more obvious it is over fuelling due to the exhaust colour. No AF gauge to confirm. It does not stall now following all the changes but idles very low and still hunts. When i shut it off it struggles to fire back up again. So, what i am now thinking is the Throttle position sensor. I have not touched this at all as yet as rather do my research before i go fiddling. Is there an easy way to check to see if the TPS is knackered. Presume it is the TPS (right hand side of the TB) and not the Sub TPS (Left side). Any thoughts or advice very much welcomed. Little bit stuck at the minute. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted February 16 Share Posted February 16 What’s the spec of the car Quote Link to comment Share on other sites More sharing options...
AMG Posted February 16 Author Share Posted February 16 BPU J-Spec tt. Nothing has changed with the spec for a very long time so something has failed due to wear or time. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted February 16 Share Posted February 16 Auto or manual? Quote Link to comment Share on other sites More sharing options...
AMG Posted February 16 Author Share Posted February 16 Manual pal Quote Link to comment Share on other sites More sharing options...
AMG Posted February 16 Author Share Posted February 16 The only time it has idled well and stable is when I have unplugged the MAP and the car stalls. Plug back in and idles normal. But then switch off and try again and back to hunting and over fueling. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted February 16 Share Posted February 16 Take engine ECU cover off and check for any blown capacitors. Super commmon that ECU's failing randomly these days Quote Link to comment Share on other sites More sharing options...
AMG Posted February 16 Author Share Posted February 16 I will give a look. I am running a blitz access ecu. Quote Link to comment Share on other sites More sharing options...
Big Supes Posted February 16 Share Posted February 16 Check the lambda sensor plug as they're also a tired these days and the car will struggle to recover back to idle while running rich. Best thing to do is unplug it and test to see if improves. Quote Link to comment Share on other sites More sharing options...
AMG Posted February 16 Author Share Posted February 16 Will put it on the list the check. Was going to replace O2 sensor shortly once got through MOT. Sods law. Will have to sorn it too. Quote Link to comment Share on other sites More sharing options...
AMG Posted Monday at 01:07 PM Author Share Posted Monday at 01:07 PM Today's update.... Checked the O2 sensor conception, all seems fine. During very rough over-fuelling idle i checked the O2 sensor voltage with battery ground and OX1 port and can only get a fluctuation of between 0.02 and 0.1v. Even after attempted cleaning i get the same. Maybe this could be the culprit. Time to replace the O2 sensor and see i suppose. Quote Link to comment Share on other sites More sharing options...
AMG Posted yesterday at 06:29 PM Author Share Posted yesterday at 06:29 PM Maybe a silly question, but are the pre and post cat O2 sensors essentially the same with different cable lengths? I have a post cat sensor and wondering if I can just extend the wires. Quote Link to comment Share on other sites More sharing options...
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