Morgenster
08-01-2006, 10:52 AM
Hi,
I've been chasing a rough idle (at startup when cold) and I think I may be on to a possible cause.
However, the M50's ignition system is a lot less transparent than the M20's and I'm trying to figure out one or two things.
First off: sparkplugwell on cyl 1 is slightly (I mean very slightly) oily. I can see a trace of it but it seems to have hardened every time I look at it. Nonetheless, does this mean I get actual leakage when the engine is running?
And how exactly does this affect ignition? I suspect the oil can f**k it up some, but I don't know how exactly.
Second: One of the coils is BREMI, the others are Bosch. How do you know that these coils function properly without removing and replacing them? Aren't there any trick tests that you can perform? The leads are covered in the Bentley manual when it comes to resistance testing, but what about the coils themselves? Is there a simple DIY test procedure?
Third: the PCV line to the valve cover is kinda loose and oily. Will replacing it do any good?
I'm planning on changing the valve cover gasket myself as soon as I've acquired the necessary items. Any other stuff I should look for while doing this?
I'll have a nice view of the valve train.
This problem is only minor and goes away the instant the car is warmed up enough, but there's always a teensie bit of misfire when I listen very closely and I want it out.
Anyway, I'm a tight budget DIYer and I really admire you guys for your knowledge and dedication but I don't go into that much work. I do like to learn continuously though, so thanks in advance for any help:)
I've been chasing a rough idle (at startup when cold) and I think I may be on to a possible cause.
However, the M50's ignition system is a lot less transparent than the M20's and I'm trying to figure out one or two things.
First off: sparkplugwell on cyl 1 is slightly (I mean very slightly) oily. I can see a trace of it but it seems to have hardened every time I look at it. Nonetheless, does this mean I get actual leakage when the engine is running?
And how exactly does this affect ignition? I suspect the oil can f**k it up some, but I don't know how exactly.
Second: One of the coils is BREMI, the others are Bosch. How do you know that these coils function properly without removing and replacing them? Aren't there any trick tests that you can perform? The leads are covered in the Bentley manual when it comes to resistance testing, but what about the coils themselves? Is there a simple DIY test procedure?
Third: the PCV line to the valve cover is kinda loose and oily. Will replacing it do any good?
I'm planning on changing the valve cover gasket myself as soon as I've acquired the necessary items. Any other stuff I should look for while doing this?
I'll have a nice view of the valve train.
This problem is only minor and goes away the instant the car is warmed up enough, but there's always a teensie bit of misfire when I listen very closely and I want it out.
Anyway, I'm a tight budget DIYer and I really admire you guys for your knowledge and dedication but I don't go into that much work. I do like to learn continuously though, so thanks in advance for any help:)