View Full Version : when engine heats up, rough idle & backfiring


wandlwilliams
07-02-2006, 10:41 PM
I have a 94 9K miles. Starts fine cold, runs fine for a few miles until engine heats up and then there is a miss in the engine. Runs real rough.
this problem started after I washed the engine but that was a month ago; plenty of time to dry out. Is there a connection or coincidence? thanks for any help.

d93vette
07-03-2006, 01:33 AM
water and a opti-spark is not a good combo. if any water is in the opti-spark(any at all) it's gonna be a problem. two went south on me,the first after the engine was pressure washed. the second was a week after a huge rainstorm, both of them had to do with water. maybe theirs some water left and it steaming up the pick-up making it miss fire when its hot.

mech259
07-04-2006, 10:54 AM
I agree. If you have the old style Optispark distributor cap without the vent, then you probably have problems. The new style cap has a vent in it to rid itself of corrosion, buildup, water, etc. Only problem, you have to remove water pump to replace cap. [:@]

bigalbeco
10-04-2006, 08:03 AM
I agree as well, but not a good idea to wash any electronic controlled engine. Cost my partner $80 for a new throttle position sensor 10 years ago on his Caddy! A customer came into my shop after washing a Jeep engine just before he was going to sell the Jeep and the transmission wouldn't shift, again, throttle postion sensor got wet. Live and Burn, Bigal