Location: Space Coast, FL *USA*
Posts: 182
My VIN: * 5945 * Oct, 31, 1981. FranKenDeLorean
Club(s): (DCF)
Yeah I was looking into some previous forum posts seeing if possibly its my lambda thermal switch that's giving me a fixed reading. I know my WOT switch isn't stuck because when I press it I can see the change in dwell.
If I disconnect the thermal switch in the y pipe can that just eliminate the possibility of getting and override signal to the Ecu and just let the 02 sensor do its thing?
Dang, I should have replaced that thermal switch while I was in there maybe.
Last edited by Beachdrifter; 05-14-2022 at 10:28 AM.
** A wave is like an empty canvas, waiting for a masterpiece -- unknown **
** VIN 5945 - FranKenDeLorean Oct 31, 1981 ** SpaceCoast, FL, USA ** DMCTalk Member/DMCOwner Since 2005
Location: Leonardtown, MD
Posts: 9,008
My VIN: 03572
Yes you can try to disconnect that wire going to the thermal switch or going to the lambda ECU. Not sure if you can pull the pin in the ECU connector. Or just cut the wire somewhere that can be connected together later.Originally Posted by Beachdrifter
Location: Space Coast, FL *USA*
Posts: 182
My VIN: * 5945 * Oct, 31, 1981. FranKenDeLorean
Club(s): (DCF)
You were right, I figured the only other option was to get rid of the overrides from the WOT switch or lambda thermal switch.
So I figured I'd just eliminate the feed of those both into the lambda ecu pin 7 by snipping that light green wire inside the ecu connector. I'm in Florida and don't see the point of the lambda thermal switch and I don't intend to be speed racer with my Delorean any time soon, so I should be ok.
After cutting that wire, I started the car and after a few minutes the dwell started to cycle. I was a bit on the high side so I brought it down closer to 20. Now it is bouncing around anywhere between 15 and 24. Not the best cycle , and seems to be intermittent at that, but oh well I'm done with asking for perfection. I left the adjustment at that since it seemed to be averaging around 20ish. It's tuned better than it was before at least and I was afraid to mess with it anymore.
Looks like my thermal lambda switch needed to be replaced when I was in the VOD, but I missed it. Oh well, I love my car, but I'm not going back in there just for that. Being iM in Florida , I'm not too worried about it. If I ever think I need it I could rig a timer switch to the wire to simulate a ground for a few minutes then open or just replace the thermal time switch when I'm in the VOD hopefully not for a looong time.
At least my car is no longer stuck in open loop.
So as they say in the movie business, I guess that's a wrap!!!
Car runs great now and that little dwell thing is taken care of.
I learned a lot from this experience.
Last edited by Beachdrifter; 05-14-2022 at 08:46 PM.
** A wave is like an empty canvas, waiting for a masterpiece -- unknown **
** VIN 5945 - FranKenDeLorean Oct 31, 1981 ** SpaceCoast, FL, USA ** DMCTalk Member/DMCOwner Since 2005
Location: Leonardtown, MD
Posts: 9,008
My VIN: 03572
Congratulations on getting her fixed.
I worked on a friends car that had very excessive hunting when extremely cold warmup. It only did it when I had it parked in 20 deg. F. temps or below. It turned out cutting that light green wire to the lambda ECU fixed the problem. So even though the mixture was adjusted to book values that rich mixture in very cold weather was to much for it to handle. My car did not have that problem however.
Anyway I don't think many owners would ever experience the need for that lambda thermal switch.
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