Diag. shows no #3 cylinder

[Kurt]

Ok here is what i know:
ford diag. shows #3 cyl is not pulling but spark duration is fine.
replaced plugs and wires and plug tube seals as they were leaking oil.
car runs like it's has 3 cyl. slight ticking in engine comp. NO power at all and has been like this for a couple of years.
60K service was done except no timing belt change. car has 91K now.
will be doing a compression test soon to rule out air.
ran into another guy with the exact same problem. he told me his started when he hosed off his engine to clean it one day. i have also had my engine steam cleaned once. any connection?

where do i start to diag this power problem? if spark is OK can it still be electrical?

 

[luigisho]

Kurt, a few questions. First what exactly does "#3 not pulling but spark duration is fine" mean in English? Just want a mental image of what that means. Also you mentioned that this occurred shortly after a steam cleaning of the engine. Is this correct? This may or may not be a factor but is worth considering as a prospective catalyst to a poor running condition, correct also?

Any codes present in eec memory? I can't see your sig.and the year of your SHO during reply so considering you have 91k on a presumably original timimg belt that may be worth considering.

 

[Kurt]

Sorry I was not more clear. What I meant is that on the diag. graph, power on the #3 cyl. drops way down as the cylinder fires. (i need to scan in pix.) If you look at power coming from each cyl. on this diag. chart, power line is flat on #1, #2, then line drops way down for the #3 cyl. the pops back up for 4,5,6. This diag. graph also plots spark duration in the cly. on the same graph. While #3 does not produce power the spark the that cyl. is consistant. this tells me (i think) that my power problem is not spark.

If power drops off it can only mean 3 things, spark, air, or gas. Spark seems to be ok. Air I am not sure yet and gas, I will have to clean injectors.

My question is, if spark duration is ok, but problem is susupected to electrical b/c this guy i met did similar things(engine cleaned), can the problem really be electrical. If it can be electrical, where do I start looking?

'95 MTX
All stock except I have a PepBoys battery

 

[Kurt]

Oh, and for codes, how do I check them. I have been to several Ford dealerships about this and none have mentioned that there are any codes. Then again all have said they have little to no expereince with engine.

 

[SolidState]

www.shotimes.com has a very good FAQ on pulling EEC codes.

 

[luigisho]

I'm not sure how things are going but seeing 91k on an mtx says timing belt replacement is a good idea at this time. Check the plugs so see if any were fouled during the engine cleaning. Scott has a picture of carbon tracking on a spark plug which can cause it to fire incorrectly. If electricity finds a path other than the proper one (maybe an arc due to moisture) the plug may not fire on time. Carbon tracks look like a black streak (or a track)on the ceramic part of the plug. A sensor failing due to moisture is clearly possible as well.

<small>[ July 15, 2002, 06:47 PM: Message edited by: luigisho ]</small>