Ginger pig 14 Report post Posted November 12, 2018 Hi Guys, It feels like I am re-living ground hog day...... So I recently completed a C service on the Esprit Turbo SE. Had a few issues but overcame them... I have just one issue left! As the title suggests; the car idles great for around 5 mins but then as soon as it goes to closed loop the engine starts to struggle before finally stalling. No engine management lights illuminated until it finally stalls. Please see attached File..... I cannot see anything untoward but I am hoping that someone might be able to cast their eyes over it and quickly ascertain what the problem could be. Your help on this would be greatly appreciated!!!! Cheers Mark 091118a.csv Quote Share this post Link to post Share on other sites
Barrykearley 5,316 Report post Posted November 12, 2018 Will it restart?? This is exactly what the IAC valve does on the old cavaliers Quote Only here once Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 12, 2018 Thanks Barry, yes restarts but only running for around 30 secs every time I restart it whilst warm. cheers mark Quote Share this post Link to post Share on other sites
johnpwalsh 1,244 4 Vehicles Report post Posted November 12, 2018 1 hour ago, Barrykearley said: Will it restart?? This is exactly what the IAC valve does on the old cavaliers Don't tell me you had a Cavalier !!!!. Gob smacked, utterly astounded in fact. Almost as bad as if you were to say you had one of Andy's favorite Audi's. Quote Share this post Link to post Share on other sites
Barrykearley 5,316 Report post Posted November 12, 2018 Ive had a cavalier - albeit only briefly. The IAC valve setup is exactly the same - and was a real problem on these cars as well Quote Only here once Share this post Link to post Share on other sites
sailorbob 169 Report post Posted November 12, 2018 When the ecu determines closed loop operation is permitted the HEGO sensor shows a rich condition and the integrator reduces the fuel to try to get the HEGO sensor to switch lean. As the HEGO sensor remains indicating rich the integrator keeps on reducing the fuel to such a point that the engine stalls. 1 Quote Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 13, 2018 Thanks Derek, is the HEGO sensor the O2 sensor? would this indicate that the O2 sensor is malfunctioning or could there be another reason for it not to be reading correctly (it was an engine out c service which meant all the exhaust system was dismantled and then refitted)? Cheers Mark Quote Share this post Link to post Share on other sites
sailorbob 169 Report post Posted November 13, 2018 1 hour ago, Ginger pig said: is the HEGO sensor the O2 sensor? Yes. Check the sensor and its wiring. Quote Share this post Link to post Share on other sites
Barrykearley 5,316 Report post Posted November 13, 2018 If the O2 sensor has been contaminated with release agent or copperslip that really tends to ruin the things. The cable can burn against the exhaust or turbo. Are the O2 levels moving in freescan log? I can’t open it on an ipad Quote Only here once Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 13, 2018 The o2 levels looked to be ok up until point of stalling. Quote Share this post Link to post Share on other sites
sailorbob 169 Report post Posted November 13, 2018 The HEGO sensor values do not look OK. When HEGO value changes from its 'HEGO Initialisation Value' (aka KO2FF0) parameter value of 0.46 volts it jumps to over 1 volt and stays there until the engine is restarted (whereupon it gets reset). Because the sensor is continuously reporting a rich condition the ecu ends up pulling over 60% of the fuel thereby causing the stall. 2 Quote Share this post Link to post Share on other sites
Clarky5150 81 Report post Posted November 13, 2018 Listen to Sailorbob. This man knows his onions! Quote Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 13, 2018 Cheers guys, new sensor then? Mark Quote Share this post Link to post Share on other sites
Bibs 8,861 4 Vehicles Report post Posted November 13, 2018 Yup, @sailorbob is spot on as usual, Esprit legend! Your O2 voltage looks like this... whereas it should look like this... Quote 88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport Evora NA For forum issues, please contact the Moderators. Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 13, 2018 Wow!!!! That’s what I get for buying an cheaper after market version!!!! Quote Share this post Link to post Share on other sites
sailorbob 169 Report post Posted November 13, 2018 Shortly after starting the engine when the HEGO sensor shows > 1 volt disconnect it and see if the voltage drops to around the 0.46 volts range. If it does then that would most likely indicate a sensor problem rather than a wiring short. Quote Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 13, 2018 Cheers Derek, that’s great advice! At least I have a clear path now! i’ll let You know once I have completed the process and hopefully have her MOT’d by next week!!! thanks for all your help guys. Quote Share this post Link to post Share on other sites
Vulcan Grey 234 1 Vehicles Report post Posted November 13, 2018 Which O2 sensor did you have? Quote Travis Vulcan Grey 89SE My Lotus Photo and Projects Album Share this post Link to post Share on other sites
tmusc 18 Report post Posted November 14, 2018 Check to see if your map sensor is plugged in. Quote Share this post Link to post Share on other sites
Vanya 530 Report post Posted November 14, 2018 @Ginger pigI had the same issue with my car when buying the aftermarket alternative from a well known supplier...mail the supplier and tell them about your experience with the part. The more of us that let them know the part isn't fit for purpose, the better. Quote Vanya Stanisavljevic '91 Esprit SE | '91 Elan SE | '97 XK8 Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 14, 2018 Hi Chaps, map sensor was plugged in. I have pulled out the o2 sensor and it looks pretty clean and unmolested. Is there any test that can be performed on the sensor at all? Cheers Mark Quote Share this post Link to post Share on other sites
Barrykearley 5,316 Report post Posted November 14, 2018 They either work or don’t. Issues with these sensors are well documented on here. the O2 voltage should sway all over the place just like Bibs post above. If it’s not doing that then it’s sensor or wiring at fault 1 Quote Only here once Share this post Link to post Share on other sites
Ginger pig 14 Report post Posted November 17, 2018 Evening gents, tried cleaning the sensor and connections in the vein hope of reviving it... alas; it would appear that this unit is dead!! other than SJ; are there any other alternatives which members would recommend? cheers mark Quote Share this post Link to post Share on other sites
Barrykearley 5,316 Report post Posted November 17, 2018 Quote Only here once Share this post Link to post Share on other sites
Chillidoggy 3,522 Report post Posted November 17, 2018 Here’s a genuine Lotus job. Quote Margate Exotics. Share this post Link to post Share on other sites
