[Johnny O]

I own an 88 924S automatic and did a lot of upgrades myself with the sensors, fuses, plug wires, I also bought 2 new dme's from F9, and I put the original in the glove box plus the spare one, just to be safe. I experienced a lot of what you are describing and for me, as it turned out I replaced the positive battery cable because of green death in the cable, but it was my negative battery cable that was causing the intermittent starting issue. So with both battery cables replaced the car starts no issues, even my gauges are working properly. I can say if you replace the negative battery, if yours is like mine attached to the back of the engine/flywheel housing. Stuff a rag or something to cover the open slot to the flywheel. Taking the nut off and cleaning the ground was easy, putting it back on was a problem (hence) Dropped nut forum on here. It's easy to drop the nut, but it's hard as hell to get it out, I ended up buying a borescope, but it still took a lot of time to get it out. Good luck mate...