91 m42 misfire out of ideas

[B-well]

car is a 91 318. 90k original miles

car has been problem free for 2k miles. then all of a sudden misfire thoughout rpm range.

replaced fuel pump (mine was whining so it was needed anyway)
replaced plugs. double platinum
replaced wires. bosch 7mm premium
replaced coils.
replaced ecu

the second cylinder coil is sparking at the coil and with plug in the end of wire it sparks, but when in the cylinder it does nothing. unplugging 1,3, or 4 causes it to nearly die but unplugging 2 has no effect.

unplugged maf but still idles rough

can the CAS effect only one cylinder? im out of ideas. any help is greatly appreciated.

[Ryann]

If you're able to pull a sparking #2 wire without any effect then you're left with compression in #2 and fuel injection for #2. You can use a Bosch noid light ($10-15) to verify that #2 injector is getting a signal from your DME.

[xxlbimmer]

Put a timing light on number 2 spark plug wire and look at the flashes and compare with others! Then, try swapping injector #2 with #3, see if it moves the problem. Hopefully a comp check was among your first items, if not do that!!

[AndrewBird]

Pull your ECU and take a look at the transitors that fire the coils. They like to get hot and burn out.



Thankfully they are easy to replace if you know how to solder. New ones are like $2 each.

If any are burned up, you will want to make sure the coils are good as a bad coil will burn them out as well.

[B-well]

swapping injectors today. hopefully thats the problem.

[dude8383]

Tps?

[bloodshot-e30]

compression??

[Dj Buttchug]

try AFM too. it may need to be taken apart cleaned and adjusted

watch vid

http://www.r3vlimited.com/board/showthread.php?p=2750133#post2750133

[B-well]

PROBLEM SOLVEDDD!!!

Bad fuel injector and the rest clogged.

Purrs like a kitten now. thanks to all