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dead cylinder on 3.8

My girlfriends 98 Mustang 3.8 has a "miss". If you pull off the #5 plug wire the engine speed does not change, it does for all others.

There's a spark there (you can see it jumping as you pull off the wire). I've swapped out the wire and plug with no difference. I've also taken off the intake and measured the resistance of the injector and the resistance of the connections off to ground. They are the same as the other injectors.

I've had the heads off recently (head gasket replacement) and the valves look good.

Is this a clogged injector, or could it be something else? I've dumped in a can of injector cleaner.

On another note, any recommendations on cleaning the sludge out. There was a great deal that I cleaned out of the heads and valley. I've done a quick flush and currently have a can of Rislone in there. I suppose we should move to synthetic when this is fixed.

Jeff

Reply to
jeff
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did you 'read the plugs'? take plugs out and see what color/condition they are in google has some photos of what good and bad plugs look like. all oily => may not be firing much, or rings letting oil by if not firing much replace pack (or distributor cap/rotor)

good luck, let us know what you found next

Reply to
sanboz

Plugs look normal.

Jeff

Reply to
jeff

Then you're likely looking at an ignition problem of some sort. Is the gap worn large? Did you try something as simple as swapping plugs around to see if the problem moved with the plug?

Might be a bad wire or dist cap issue as well. (provided the 3.8 had a dist that year, don't know)

Reply to
Brent

I believe I mentioned that I did. I had the last set I had taken out and swapped the wire and plug. That was step one.

No distributor.

Jeff

Reply to
jeff

read it three times and missed it each time...

Really odd coil pack failure? Although the paired clyinder should be having problems too.

If the valves are good, there's no nasty noises of something broken inside the engine, the plugs look normal (no oil fouling), there is fuel, swapping out plug and wire did nothing, the only basic thing left to suspect is the coil as strange as it seems.

Reply to
Brent

Think he said good spark too, I heard other people mention nodes to check injectors, might check that out Jeff.

Reply to
GILL

visible spark, which may or may not be good enough.

Reply to
Brent

Generally, a good spark will jump about 1/4", or make you say SHIT! :)

Reply to
GILL

See if the computer is setting a lean (injector closed) or rich (no spark) codes and the plug looked normal.

Reply to
George Jetson

Swap a couple of injectors and see if the "miss' moves. Take a compression test. It's OBD II. Got any CEL codes?

Reply to
Kruse

OK, I'll do that.

Jeff

Reply to
jeff

Finally... someone said the magic, relatively unintrusive thing..... a compression test...

followed by scan for codes (which might be a bit late now that so much stuff has been disturbed/disconnected...

Swap a couple of injectors and see if the "miss' moves. Take a compression test. It's OBD II. Got any CEL codes?

Reply to
Jim Warman

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