95 Lesabre Missing Severly

3.8 engine - missing badly in 1st and 2nd - SEVERLY in 3rd (Automatic trans). Have changed plugs and wires and fuel filter. 1st couple times it happened and cleared up (did insert gas heat - don't know if that was why or not) in a couple hours. Next time it didn't clear up - and mechanic friend said he found wet plug in #2. cleaned & put in diff cyl and problem stopped for a couple days. Then I replaced all plugs etc. and it still has not stopped. seems to go from running on 5 cyl to 4 with the way it chugs and lags. MPG cut about in half. Am going to sons house tonight to look at injectors, but really have no idea what we are doing from this point on. HELP please?

After what you have done aleady I would test the injectors just like you say you are. Have you check the computer codes? it may lead you in the right direction too. Does it miss when it is in idle too?
Have you looked for vacume lines detached? How is your fuel pressure? have you tested piston compression? The book also list incorrect ignition timing as a possiable cause. I might also look at having the ignition module tested and the ecm after that (testing them is free at any autozone).

After what you have done aleady I would test the injectors just like you say you are. Have you check the computer codes? it may lead you in the right direction too. Does it miss when it is in idle too?
Have you looked for vacume lines detached? How is your fuel pressure? have you tested piston compression? The book also list incorrect ignition timing as a possiable cause. I might also look at having the ignition module tested and the ecm after that (testing them is free at any autozone).

Thank you - we tested the injectors and found one not working - replaced it and presto - running smoothly. Since I have 130,000 on her - I will probably try to find 5 more injectors at a reasonable price and change the others too.

Thanks again....