Slowing down stumble

[agk]

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

[Barrykearley]

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 👍

[sailorbob]

A datalog (preferably from Espritmon or TunerPro) of when this occurs would help in diagnosing the problem.

[CarBuff]

agk DID do a relearn.  We don't know the TPS readings (he DOES have Freescan).

[Barrykearley]

That TPS needs to be checked. If it’s set too low then it can cause the issue described 

[agk]

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. 

[ragingfool35]

EMH 3 page 17 and 18

[pureguava]

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