Ahhhh. Sounds like your coil may be on the way out!
Location: Vancouver, BC
Posts: 3,385
My VIN: thirty two 'o five
Club(s): (PNDC)
Ahhhh. Sounds like your coil may be on the way out!
Dave
Here, somewhere.
Usually heat related failing may be the ignition coil or the pickup coil. The pickup coil really needs good connections so check that two pin connector from the pickup coil that goes into the "firewall". Mine was so bad, I just cut the connector off and soldered the wires.
Dave M vin 03572
http://dm-eng.weebly.com/
Location: Sudbury, ON, Canada
Posts: 46
My VIN: 11633 (and formerly 3133)
Aha. I did have some slightly melty wire insulation near the top of the coil. Everything seemed sound, though.
I'm going to go after the coil right away, but since I already put this together, here's a more complete video (audio is essential). It's subtle, but the random rev-rev-purr-rev-purr-purr came at the same time as the low power during accel issue:
https://www.youtube.com/watch?v=JgG7_VxjMDs
Location: Sudbury, ON, Canada
Posts: 46
My VIN: 11633 (and formerly 3133)
Replaced a burned connector (the white/grey wire) on the coil, and found that it was also very loose. Replaced, snugged it up, and of course it's still exactly the same, lol. I have a tach connected to that pin and I do recall it going blank once while driving about a month ago, so I'm sure that connection was a bit wonky for a while.
I have a UF2 coil ready to pick up in town, but despite Partsource saying it is compatible, I'm skeptical. It will take me days to get a Bosch, so I was going to try out this UF2 to see if it at least fixes the issue until the Bosch comes.
Driving season is too short in Sudbury, ON and British Car Day is coming up soon, where I plan to attend with my Sinclair C5 on the luggage rack, so I'm hoping I can figure this out soon. Pretty sure the lambda system route is a red herring and likely wasn't working all along.
IMG_7264.jpg
Posts: 11
Just an observation of something you mentioned. This may sound crazy but take your are cleaner off and check the box and air filter for obstruction. You did mention our Canadian tree rats(chipmunks). It could be possible they made a nest in the air filter box? Don't ask!
The second I would recommend would be to run the car at night with the engine light off and see if you have any arching from the ignition wires. Sounds like you checked most items but haven't touched these. I had a similar issue a few years back with old stock wires and only caught it while checking it at night. It was an intermittent 1st of July!!
Hope you make it to Bronte!
Location: Sudbury, ON, Canada
Posts: 46
My VIN: 11633 (and formerly 3133)
Thanks. It wasn't the coil. :/ I swapped it, then started rejoicing when the idle was cleared up and I was able to do a lot of stop/starts without any issue. It was literally when typing out the word "eureka" on my phone that the idle suddenly went south again.
I haven't had much time to look at this recently, but I'm hoping to again soon. My next port of call is exactly what you are suggesting –*arcing or other plug/wire issues. It should have been my first thing to check, but I went way down the wrong road (I think) trying to diagnose the lambda system issue.
Location: Northern NJ
Posts: 8,583
My VIN: 10757 1st place Concourse 1998
It is rarely the coil unless it is not the original one. If the idle is good on startup and during warm up and then gets bad it is probably the Lambda system. Once the motor warms up the Lambda system is supposed to go into "closed loop". If it isn't functioning as it should the idle will be bad.
David Teitelbaum