george 88gta

iTrader: (1)

Car is a 1988 GTA, 305 TPI, basically stock except for a 1993 LT-1 cam and 1.6 roller rockers. I keep burning out distributor modules. I replaced the distributor with a billet one, same problem. I have tried the grease that comes with the modules, silicone dielectric grease and the white thermal grease. I have tried different coils (GM, MSD and Accel). Plug wires are new Taylors, cap and rotor are new , with brass terminals. Plugs are the stock Ac Delco's. Wiring to distributor looks good, no apparent damage. Originally, it would fail if I leaned on the gas after running for about a 1/2 hour. Car would accelerate, then start misfiring and die. Wouldnt restart, had to be towed home. This happened twice. I recently installed a rebuilt GM distributor with a new module and pickup coil. Been running for about 300 miles. Out cruising today for about an hour and was running about 40 mph. Car started to miss and died. Bad module again! Fortunately, I now carry a spare module and some tools. A week or so back I had the car idling and I used my IR thermometer gun and the temp at the base of the distributor was 145 degrees. I am running a 180 degree thermostat and the fans work correctly. ECM is a rebuilt from GM, less than a year old. Is there some way to test/meter out the damaged module to see which line is failing? Could I have a wiring harness issue?

Sparkytfl

Stock type spark plugs, or stock as in the original ones? Are they set to the right gap?

Apeiron

You're cleaning the heatsink surface and using thermal paste when you install the new module? Plug gaps are set correctly? Wires are new? Coil resistance is normal?

george 88gta

iTrader: (1)

Plugs are the stock AcDelco (R45ts?) gap is set to .045". Plug wires are new Taylor thunderbolt 2 (I run them over the valve covers). Old grease is removed and new grease applied. I didnt check coil resistance, but I have tried different coils. What is the procedure to verify coil resistance? I relocated the grounds ( at the back of the heads ) to separate bolts. Star washers and anti-sieze to maintain a good gonnection. I actually ran a separate ground wire from the battery negative wire (at the power steering bracket) to both of those bolts, so I dont think grounding is an issue.
OK, I just checked. The plugs are AcDelco R45ts and the gap is .045"