please help, im so frustrated...

[takumei86]

i just installed new bosch spark plug wires, new champion spark plugs,i just replaced the vacuum(sp?) lines, valvecover gasket, sparkplug tube gaskets, and fuel filter, AND IT STILL FUCKING MISSING!!!!!!! ugh im starting to hate this car!  its a 1991 bmw 318i with the m42b18... please help!!!


im thinking it could be the ...

1) fuel pump
2) coils
3)TPS
4)idle air control valve...

[takumei86]

no one???

[peerless]

First pull out the champion plugs and throw them in the trash. They are champions of misfire.

I have tried them twice in different cars and both times they caused misfires. You only bought them because they where cheap. Man up and buy the NGK's at about $4.50 per plug. Sorry if that seems harsh, but as I have been quoted as saying before, 'you buy cheap, you get cheap'.

And is it possible that when you changed the wires you got the firing order out of order.?

Is it possible you have a bad coil?

(this is not meant to indicate your coils are bad, but to reinforce the notion of quality parts, including spark plugs.)

As a mention of buying cheap, my friend Colin did a COP conversion. He is always looking for a way to save a few dollars, and don't we all? He purchased some no-name coils from FCP Scrotum. He pulled in this morning with a full misfire. I started pulling the wiring harnesses from the coils and bam, #3 makes no difference. Pull the coil and replace with another one, luckily they sold him 6 instead of 4. Problem solved. These coils have less the a few hundred miles on them. So now he has to go out and buy all new coils from a reputable manufacture such as the dealer. So the money he saved by buying the no name coils is now going to cost him the original amount he spent on the 6 coils and now he has to purchase 4 more.

"You buy cheap, you get cheap" End of story.

Just because something is new does not make it good. In this world of short cuts and declining quality, nothing can be trusted. The only parts I trust fully is BMW factory parts and even then they occasionally fail early.

If you where local to OC, CA I could help you out. But since no one on this board seems to indicate their location I have no clue where most of you are from.

[takumei86]

im in torrance california, i bought some "bosch platinum +4" spark plugs 6.99/ea and made my motor run worst, i replaced the champions and runs alot better!...lol

[peerless]

Just got back from Mcdonalds of auto parts, or Kragen as they call it. I picked up my NGK's as I had to order them. They are the original dual electrode design. While I was there I asked to see one of the champions they had in stock, universal single electrode design. NGK $4.59 per plug, Champion, $1.46 per plug.

The champion #3344 is a universal plug that fits everything from Chrysler, dodge, ford, chevy, bmw, my grandpa's chainsaw, my neighbors lawn mower, my weed wacker, etc...  and on and on and on.

The NGK BKR6EK plug is a little more specific and fits BMW, Porsche, and Saab, including turbo models and M3 models. I also believe it is specified by BMW in the owners handbook.

Plugs play a much more important role then you might imagine. You get what you pay for. The point I am trying to make is while your misfire problem is frustrating, your not doing yourself any favors by purchasing plugs that are not specific to your application.

[Jimmy Lewis]

Well, you can always pull the wires while running, you know the drill if you have a bad coil, now that you know the wires are good. Other than that, you could swap the connectors of two coils and their respective wires and see if the misfire also moves to the swapped coil. There are other things you could check, but a genuine misfire has to be a singled out plug/wire/coil or a single clogged injector, which I don't know the symptoms of. My issue sounds exactly the same as yours, new wires solved my problem, maybe yours is a bit farther upstream being the coil. Goodluck.

[kowalski]

miss fires can also be from a bad crank or cam sensor, check them both hot and cold with an ohm meeter.

+1 with the for pulling the plug wires while running to figure out which cylinder is missing.

[bmwman91]

I had some nonsense like that last year.  It was a pooped AFM.  After ridding myself of it, not another single problem.

[BMWManiac]

I had some nonsense like that last year.  It was a pooped AFM.  After ridding myself of it, not another single problem.

The air mass meter connected to the intake?  What do you mean you rid yourself of it...removed it?

I just bought some Autolite plugs...yes, they were cheap too...hell, I run $2 BKR7E in my 97 turbo M3 and they are just fine!  I guess I'll go find some BKR6E plugs tomorrow and see what happens.

[bmwman91]

The air mass meter connected to the intake?  What do you mean you rid yourself of it...removed it?

I just bought some Autolite plugs...yes, they were cheap too...hell, I run $2 BKR7E in my 97 turbo M3 and they are just fine!  I guess I'll go find some BKR6E plugs tomorrow and see what happens.

Well, I converted the VAM the car comes with to a MAF setup.  THe cheaper and easier option is to get a refurb'ed one (after borrowing a known good one).

[twinpop171]

First pull out the champion plugs and throw them in the trash. They are champions of misfire.

"You buy cheap, you get cheap" End of story.

+1:D

NGK's work for me.  Many members here really don't care for the Platinum +4's too.

As mentioned previously keep moving upstream with your testing of parts.  These motors are really pretty simple.  Take a deep beath and be patient.  If you need coils I still have my four used ones that worked when I removed them.  If you want a nice upgrade buy the BavAuto HP coils.
Dan.

[BMWManiac]

I just installed NGK BRK6EXs and will report shortly.  I noticed a lot of crud buildup in the coil boot itself, so may be a possibility