Engine has a miss under load

[oldone]

My car has about 250,000 miles on it and about 6 months ago it developed a pretty substantial miss under load steady state cruising. I changed plugs, cap, rotor, and wires but it didnt improve it any. Just ran a compression ck and i had a low of 175 to a high of 185 so that part is good. It starts and idles fine, and the miss seems to get worse as it gets warmer. About a year and a half ago the dist ignition module went out, i ended up getting a used one from the JY and it has run fine up till now. Ive read where people say it may devlop a miss if the module starts to break down. Would like some opinions before i shell out the money to try a new module. My experience is that they either work, or they dont. Any help or suggestions would be appreciatted.

Thanks

Jeff

[Flyin4stroke]

Have you checked the fuel filter in awhile?

[oldone]

I believe i did about a year ago. But if not i will change it and see if it helps

[WmWatt]

You can take the ignition control module out and take it some auto parts stores for a free analysis. You could also try putting dielectric heat transfer past under it. I got two bubbles of the stuff at an electronics store near here for $1. That's enough to do 4 ICM's. It's the stuff they put under CPU's in computers. If you buy a new ICM (all made by one company in Japan but retail prices here ran $150-$300 when I did mine) put the paste under it to help it last.

[oldone]

ignition module

I will try and take the module in today and get it checked. Anybody ever have any luck with the ignition modules off of Ebay? A couple years ago when my unit failed i bought one off ebay and it wouldnt work, i exchanged it twice with the vendor but never could get it to work. Thats when i went to the JY and got the one thats in it today. Just curious since im probably going to end up buying one and just wanted to find the best deal. If anyone knows of a vendor on ebay that theyve had good luck with on these modules, i would be very appreciative.

Thanks

Jeff

[WmWatt]

I called local parts stores. The closest one matches competitor's prices so I got the lowest price. A new module has a 50k km 5 yr replacement warranty. If you buy new save the reciept.

[Christ]

The module can begin breaking down internally by having intermittent arc across circuit lines.

Check also your crankcase vent and egr if equipped. Clean egr passages and valve, etc.

Try driving until the miss develops, then go to neutral, shut the engine off immediately, and coast to a stop, check the plugs for coking. One cylinder may be quenching the spark (blowing it out). Try getting hotter plugs, or gapping your plugs .010 smaller.

I thef problem starts to clear up with any of those things, report back and we can continue diagnosis.

[oldone]

I took the module to the local auto parts stores (Advance, Autozone, Oriellys) but none of them could check it, none of them have a connecter harness that will fit. Checkd crankcase vent, it was clear. Performed driving test, no coking or carbon on plugs. The plugs were new so i regapped a bit tighter, still the same miss. Rechecked timing, it was spot on. So i just went ahead and ordered another module off of the internet, i bought the Mitsubishi model which is what it had on it when i first bought the car, and what i currently have installed. I will repost after i install it and see if it fixes the problem. Thanks for all the help so far.

Jeff