agk 4 Report post Posted June 5, 2019 Hi All, As I've got my car back on the road, after a recent engine rebuild etc, everything works OK. However sometimes, when slowing down, before coming to a complete stop, while still in gear, the engine may stumble and stall. I restart the engine, keep driving and all is OK. Before the rebuild I don't recall that happening noticeably. I was told that it may be a IAC (Idle Air Control) valve issue, it may need to be replaced. Can somebody please advise on this problem and if it's related to iAC? I can provide more information on what has been done on the car during the rebuild. However the IAC is original. Please advise, thank you in advance. Anton '95 Esprit S4s Quote Share this post Link to post Share on other sites
Barrykearley 5,618 Report post Posted June 5, 2019 Yup could well be. Rockauto is the place to get a replacement - about £20 and shipping only takes a few days. before that though - it’s be worth plugging into a pc and resetting the ecu and doing a relearn cycle to see if that changes it. Also check the TPS is set correctly - that’s important Quote Only here once Share this post Link to post Share on other sites
sailorbob 214 Report post Posted June 5, 2019 A datalog (preferably from Espritmon or TunerPro) of when this occurs would help in diagnosing the problem. 1 Quote Share this post Link to post Share on other sites
CarBuff 141 Report post Posted June 5, 2019 agk DID do a relearn. We don't know the TPS readings (he DOES have Freescan). Quote Atwell Haines '88 Esprit Succasunna, NJ USA Share this post Link to post Share on other sites
Barrykearley 5,618 Report post Posted June 5, 2019 That TPS needs to be checked. If it’s set too low then it can cause the issue described 1 Quote Only here once Share this post Link to post Share on other sites
agk 4 Report post Posted June 6, 2019 Hi All, Thanks very much for your help! I have some further questions: 1) What's the procedure to check if IAC is working correctly (or not)? 2) Same question re: a procedure for TPS? BTW, I checked that Freescan has some TPS data; at least there is a TPS column in the csv log dump file. Please advise, thanks very much. Anton. Quote Share this post Link to post Share on other sites
ragingfool35 21 1 Vehicles Report post Posted June 6, 2019 EMH 3 page 17 and 18 Quote chris90SEjust because I don't CARE doesn't mean I don't UNDERDSTAND Share this post Link to post Share on other sites
pureguava 53 Report post Posted July 23, 2019 Hi - my S4S did this after work on it - battery disconnected etc. It was just the ECU relearning and self remedied after about 20km or so......don't disconnect battery and keep driving.....I hope your problem is the same as mine Quote Share this post Link to post Share on other sites
