Missing misfire

[jaybee]

Head gasket replacement on my '95 Ford Windstar 3.8L went smoothly but I still can't get the thing back on the road.  The motor now has a miss in it that I just can't cure.  Initially I got the pushrods and rocker stands on the front cylinder bank in reverse order which left the #6 cylinder with valve lash very loose and #4 too tight, hanging a valve open.  Does that qualify me for Team Smart?  I still have a dead miss but can't seem to track it down because it moves around the engine!  Sometimes 3, sometimes 4, sometimes 6???  I have compression and seem to have spark and fuel, where the heck do I go from here?

[wayne petty]

how are you testing for missfire?    trouble codes??

pulling a spark plug wire>   thats probably not a good idea with DIS...

http://www.autozone.com/az/cds/en_us/0900823d/80/1d/30/20/0900823d801d3020/repairInfoPages.htm

i dont know what for recomends to do a short a plug wire out test..  i used to use short sections of vacuum hose... (yes its conductive and short it to ground with the tip of a test light... i now use my hand held automotive scope.. (from harbor freight about 8 years ago)


are the spark plug wires all working?  measured with a dvom..  200K ohm scale...  wires should be longer in inches than the reading on the meter.,,

24 inch long spark plug wire lead.. should read less than 24 on the display... usually 10 to 14...      

the spark plug connectors inside the boots also pull off and cause weird problems...

i worry about the coil failing... or high voltage leaks..

[jaybee]

I'm getting my misfire information from trouble codes.  I've put my spark tester on the plug leads and get a good, fat spark.

[enjenjo]

I'm getting my misfire information from trouble codes

This is a good clue. You need fuel, air and spark  to fire the cylinder. You have air and spark, therefore the fuel must be the problem. As I recall, the Gasket blew, letting coolant into the cylinders. You may have a contaminated O2 sensor It can also be low fuel pressure, a plugged filter.

[wayne petty]

it could be all of the above...

any chance the fuel injector electrical connectors are not pushed all the way in...  ?



this is a waste spark system there are 3 dual terminal coils in the coil pack. as the  coil generates a high voltage spark... it goes out one wire  jumps a plug.. through the head, block. head.. jumps the other plug back up that wire to the other terminal on the coil...

so if one wire , plug boot or plug is bad it may kill the pair of cylinders... intermitantly or continiously..   look for high voltage leaks at the spark plug boots..

also verify that the image of the wires above matches the wiring numbers on the coil pack... i seem to recall that there was some  manuals with incorrect data on dis spark plug wires location on the coil.......

[jaybee]

Thanks, that all makes sense.  To run it down;
-#4 cylinder blew to the water jacket.  It certainly forced coolant out the exhaust and I'm pretty sure some got dumped in there while pulling the heads as well.  This would also help explain why the spark plugs in question can't seem to decide whether they're sooty rich or almost white lean.  Can an O2 sensor be cleaned, at least to the point where it will tell me if I'm on the right path?
-Fuel pressure is within specs.
-Electrical connections on the injectors are all seated firmly.
-The waste spark path helps explain why 3 and 4 would both show misfire, they are after all on the same coil.
-I wonder if I accidentally smeared some anti-seize onto a spark plug insulator, possibly transferred from the plug socket onto the #3 plug where I was working blind?
-Plug wires are in the right places, I didn't take them off the coil pack and the way they're loomed they'll only work one way.

[jaybee]

OK, I think I found something, if someone can tell me if I'm either correct or off base I'd appreciate it.  The instructions I'm using for valve adjustment say simply to tighten the rockers to 44 inch lbs, then go back and tighten to 22-29 lb lbs.  That's sufficient to get the rocker stands seated onto the heads but it just struck me as wrong.  It just doesn't seem like the valves that are open are really going to be torqued the same as the ones that are closed.  Turning to the pages dealing with the 3.0L version of the same Duratec engine it gives a far more detailed procedure that ensures torqueing the rockers while each lifter is on the base circle of the cam.  I think the valves that were torqued while open are insufficiently torqued and some of them have probably loosened.  Right?  Wrong?  Shouldn't matter?

[Fat Cat]

Here is what I could find. It comes from Mitchell On Demand

[jaybee]

Ouch!  ENORMOUS ID10T ERROR!  I let one of the rocker fulcrums get twisted in the rocker arm when I tightened it down, shattered the rocker arm.  On the positive side the engine ran until I shut it down, the oil pressure light never came on, and the valve still moves up and down smoothly so maybe it didn't hit the piston.  I found enough major pieces of shrapnel to build a rocker arm but expect that some very small pieces got into the oil pan.  This is quite possibly the dumbest thing I've ever done inside an engine.  Hoping for the best but this was a big time screwup.

[wayne petty]

did the rocker arm shatter or the fulcum..?

are the rocker arms magnetic ?       or at least they used to be...

the fulcrums are aluminum?

got a parts tank sump pump...  can you drain the oil into a really big pan and put the solvent pump into it...  circulate the solvent through the motor and out the drain pan till all  the parts come out...  you might need to jack up one side  of the car to get enough angle to get the parts across the bottom of the pan.... if it is a cast aluminum pan... there may be deep pockets in it that may catch the debris...

how hard is it to pull the pan... shows 3.3 hours in my rate book...

the oil pump screen is melling #270S   those screens can trap debris in them...  looks like there is no pan gasket only rtv and end seals...

[jaybee]

Rocker is shattered, the fulcrum is jammed inside.  It is not magnetic.  The pushrod isn't visibly bent but undoubtedly is bent.  Looks like the valve was closed when I tightened the rocker.  The pan is steel, and I don't see any way to get it out without pulling the engine.

[Dave]

Rocker is shattered, the fulcrum is jammed inside.  It is not magnetic.  The pushrod isn't visibly bent but undoubtedly is bent.  Looks like the valve was closed when I tightened the rocker.  The pan is steel, and I don't see any way to get it out without pulling the engine.

You really are trying to make the team arent you  :?:
Sorry about your luck . I hope it all works out ok and your under consideration as a new member.. Like that helps
Dave

[wayne petty]

a cheep item from HF to support and lift the motor in the chassie

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96524

40 bucks....

i have an earlyer single screw vesion and there are some jobs that cannot be done without it..

[EMSjunkie]

You really are trying to make the team arent you  :?:

Dave

send him an application    

Vance

[river1]

You really are trying to make the team arent you  :?:

Dave

send him an application    

Vance

don't you guys think he's had a bad enough week :x  :cry:  :x  :cry:

later jim