the car is a 90 integra automatic. after installing a new water pump last week, i have a random missfire when the car is warmed up. it doest do it untill the idle comes all the way down and the temps come up a little. i know that i installed my timing belt right, and i also put in new plugs and cleaned the contact points on the wires. ive bleed the coolant because while searching through, i saw some info that said that could be the problem. what else should i try? new wires? rotor? cap? bleed the coolant some more? my timing? i didnt check that because i wasnt exactly sure where the mark on the block is (im new to working with acuras). the car runs fine, its just that when at idle i have that miss. no cel or strange sounds or anything. what could it be?? please someone help me out. thanks

 

my teg has the same symptoms.
Well im sure sometimes the engine missfires but mamages to stay idle. When that happens, the engine light should come on and your car should be in "limp mode" therefore you cant rev past 3500...my teg is a 94...so i dont know if it has the system or not. Now i checked the code that it was throwing (search this forum on instrucions how to) and it gave me a code 4, which might not be the same on yours, which means "Crank Position Sensor". In simple terms, it means your computer has no idea where your timing is at and missfires as a result. This sensor comes built in to a peice of the distributor and doesnt come cheap. good luck

 

well im not getting any CEL. so does that mean its not a missfire? its like it idles fine at 750 and then about every 10 seconds, it hickups, and then goes right back to idleing at 750. when it does dip, it goes to about 600 or 550. i know that the missfire codes are 71-74 but i would get a CEL light if i was missfiring? is that what your saying?

 

ya the car should detect missfires...but your drops in rpm arent as rough as mine so they might be going unoticed....also check your fuel pump the engine might not be getting the gas it wants...also the usual wires/plugs/cap n' rotor should also all be checked out and mayby changed....

 

Sounds like a air bubble in your coolant system. When the bubble passes by the water pump it will cause the motor to slightly rev up.

 

yeah, thats what ive been thinking also. either that or the plug wires. whats the correct way to bleed the coolant? i know where the valve is. and ive just been running the engine and opening the valve while its running. every 5 minutes or so. am i doing it right?