86 3.2 Warm Engine Bucking

[Ninetyschilling]

Anyone out there experience warm engine bucking in the mid throttle area? During the last couple of weeks I have been experiencing bucking and then ultimately engine stall in my 86 3.2. No mods, completely stock, and this only happens late in the day when the car has been sitting out in the sun while I'm at work, or if I leave it idling for ~ 3-5 minutes???? After the car dies, I can try to restart, but initially it only cranks over, and once in a while I get a heavy wiff of gas. If I let the car sit for 5-10 minutes it will start and run for a short period of time and then begin the process all over. Yesterday, I made it to a car wash and sprayed cool low pressure water over the A/C condenser and a bit on the heads, then the car ran fine till I got it home, ~ 4 miles down the road???? I checked the CHT ohm reading with a warm engine it was between 200-300ohms. Check the DME relay connections under the drivers seat, they seem to be good. I'm inclined to believe that the CHT is the culprit, even though the ohms check out, I can't think of anything else that would cut the engine out only when its hot outside, or the car has been idling, and once the engine compartment was spray/cooled down the symptoms go away. Nevertheless I'm open to suggestions before I go replacing parts blindly.

Thanks,

[Tippy]

Do a search for words like hesitation, bucking, cutting-out, surging for Carreras and kick back and have a good read.

You will pour through hours of stuff.

Maybe your DME (the ECU) has a bad solder joint? Once the DME gets hot, it can cause the board(s) to expand opening a solder joint(s) and give you fits.

Of course, the DME relay under the seat has done the same to others too.

Good luck as there is a lot of things that can cause this.

Also, an ignition coil can do the same as they are "self healing"......

[Ninetyschilling]

Thanks Tippy, never thought about the coil, my 88 635csi did the same thing come to think of it, and the coil was the culprit.