Why is my engine misfiring?

Engine Performance problem
1997 Ford Taurus 6 cyl Front Wheel Drive Automatic 197k miles

Car starts and idles fine. No engine codes. Around 45mph I get a intermittent misfire. The car stumble every 15-30 seconds. It will do it at 55mph also but not near as frequent. Have replaced plugs and wires, no help. All the old plugs looked the same and prett clean. Any help? Fuel or Ignition? Thanx

It is so small of a stumble, I would say one cylinder. Fuel pressure, wouldn't that make it worse at 55? Six coils, how do I check them?

No Check Engine Light, no Codes.?

Engine Performance problem
1997 Ford Taurus 6 cyl Two Wheel Drive Automatic 130k miles

My Taurus runs fine about 75% of the time and misfires about 25%. It will run fine for 10-15 minutes and then misfire for a few minutes and then go back to running fine. My code reader says codes # P0352 "ignition coil no. 2 primary circuit fault" and #P0303 "cylinder #3 misfire detected". I replaced the coil, spark plug wires and the spark plug to cylinder #3 and it still does the same thing. I removed the spark plug wire while it was misfiring and it certainly is cylinder # 3 that is the problem.

Got a solution?

Hmm, sounds like you're guessing too!

I only presume that it's got good compression since compression is not usually a part time thing. I don't know whether its got a spark on cyl. 3 or not, I only know that I replaced the coil, wires and cyl. #3 plug. What ever signals the coil to spark that cyl. May be out of whack (it used to be the rotor in the distributor cap, which they don't have any more). How do I figure that out?

How can you find out if it's the fuel injector without having to go to the trouble of replacing it?

My car is misfireing on the # 1 cylinder I cheaked the pluges and wires. The coil look like its new. What could the problem be im out of ideas. Thank you Allan Zolinski

Greetings. This is a 3.0 GL model. Recent blown head gasket between #1 and 2 cylinder. While off I had the heads pressure tested and magnafluxed; discovered several cracks. Acquired a set of aftermarket heads, and populated them with the old valves after cutting, new seals, etc. Put it back together and it started posting 302 code w/check engine light blinking. Replaced plugs, wires and swapped coil pack with a known good one. Code returned after 5-10 miles driving. A miss can be felt during driving. I decided to remove and clean the injectors. All injector coil resistance consistent around 19 ohms.

New seals, pintles and filters as well. Upon re installation I moved the #2 injector to the #4 cylinder position. Cleared the codes. After a short drive it posted codes of both 302 and 304. I plan to move the injector from #4 back to #2 but have yet to do so. There are no apparent vacuum leaks, and least none observable. Compression is consistent and steady between 155 and 160, with the exception of #2 which is 125lbs. Which seems odd. At this point I'm just soliciting opinions to see if I'm on the right track or overlooked something that could be obvious to you. Any suggestions would really be appreciated. Thanks.

Thanks. I was leaning toward that possibility. Two questions though. Do you know where I could get an illustration of the individual injector wring that corresponds to contact points on the ECM plug? And secondly, any thoughts on that #2 cylinder having compression about 20% less than the others?

I just wanted to follow up on this. I checked the valves in #2 just to be sure the rockers were torqued properly since there's no valve adjustment on this engine; all good. While I had it apart I swapped injector 4 back to #2. When reinstalling the upper intake manifold it seemed to not seat properly. After rocking it around a bit it appeared to seat fully. When I started it up, miss was gone and the engine ran smoothly. Drove it for about 50 miles to test it and it continued to run strong; no miss and no 30x codes. I can only think that the upper intake manifold was not seated properly on the first go round.
After a couple days new codes postes; 0430 and 1744 but I think that's unrelated. Just wanted to let you know the outcome.
By the way, for a 1744 is the TCC solenoid actuator internal or external to the trans?

Merlin, first off, right you are on the year. It's my son's car and I just had 1995 in my head.
Anyway your reply is quite a mouthful and I appreciate the detail you provided. Considering the specialized equipment, familiarity with what a Quick or KOEO test is for example, detailed wiring and connector diagrams or the Maintenance Analysis procedures of the manufacturer; you made it very apparent that I would be biting off more than I could chew if I started messing with the transmission.
Thanks again for all your help. Although it appears to be running/shifting fine over the past 500 miles or so, I guess he'll just have to drive it until the trans gives it up. Tom