Over the weekend I installed a new radiator on my wife's justa clubbie.

It's got 160,000 hard miles on it. But recently has began to stumble at idle, and the magical MIL has come on. P0302, misfire cylinder 2.

I got this... Popped off cover, moved coil #2 to coil #3 and vice versa. Cleared codes. Came back.

Swapped plugs, both looked the same (maybe 20k old). Cleared, and the code returned.

Hmmm while it was running, I disconnect a coil pack one at a time. Engine idle changed for every cylinder but #2. Like the coil is dead, but it's a known working one from cylinder 3!

I guess I gotta chase wiring now?

Any advice on where to start?

 

You checked for spark and that step 1. Step 2 is fuel. Swap fuel injectors and see if that changes anything.
Also, check compression to be sure.

 

I'm not getting spark though. The coil is getting nothing. I need to find out why. Is there an ignitor or do the wires trace back to the DME?

 

the wires trace back to the DME.

Sometimes, when the fuel injector is bad, the DME disables the ignition coil.

You could remove the spark plug on cyl 2 and run the car. notice any puffs of fuel or smell. also you could place and hold a piece of paper on top of to see if there is air movement (old school compression check).

 

When you checked for spark at the coil did you have a spark plug inserted in the coil and the base of the spark plug grounded?

There should be 12 volts and ground at the coil connector and a trigger.

Key on / engine off you should see 12 volts. If you don't find which pin is coil power at the DME and check for continuity between the coil connector and that pin. if that is good check the ground side.

Check for resistance between the ground terminal at the coil connector and any good engine ground. The resistance should be less than .005 ohms. If it's not start checking engine harness grounds.

If it is that low or lower and you have 12 volts then check for continuity between the trigger pin and the DME. If that checks good then you probabaly have a DME internal issue.

Hope that helps

 

That excellent info, thanks!

Now I just gotta find out which pin is which. There are 3 pins in a triangle pattern. Or what color wire is what.

 

https://www.newtis.info/tisv2/a/en/r...nition/ZiEgFP4

 

Bookmarked that!!

That's huge, thank you so much....

 

Grounds all check out, green wire on all 4 coil connectors is 12vdc, the other wire color in all 4 is 6vdc.

 

so does that leave you with fuel injectors?

 

I found some corrosion on the tips of the coils where they contact the plugs. Cleaned it off, it ran well for 5 min, then the code came back.

i cleared the code while on the highway. Never returned.

Ok, I have read about stretched timing chains. That would cause crappy idle, rough starts but smooth highway cruising, right?

Part of me thinks the DME is a cause too

 

Someone posted, check the compression. With that many miles, a definite possibility.

 

Yup, finally got around to it.. 185, 75 195, 180

Leak down pushing air out the exhaust...

Looks like burnt valve on cyl 2, or something.

Looks like the head is coming off soon!

Anyone have the camlock tool I can borrow?

 

Chipped valve, exhaust, cyl 2...

Just going to lap a pair of valves in and reassemble with all new gaskets.

It's fun finding tools that work... 🙄

 

Good thing it's not an S, chunk that big would prolly take out the turbo..

 

Holy carp! After trying 3 different rental valve spring tools that failed to fit, I settled on the cam tool from Amazon for $20.

You set up 2 bases bolted to the cam bosses, and slide a bar in between them, and a cam lever tool pushes down on the spring... Brilliant!

All ready to go back on!

 

Finished it yesterday. New everything, gasket wise. Started perfectly the second time, guess it had to learn parameters. Bled the coolant, came up to temp. All acting normal, parked it and went home.

TODAY, I figured it needed a shakedown. Took it around town and then on the highway. In about 10 miles it felt weird like a misfire, no MIL came to a stop and WOAH. Big lope, but no misfire like before.

MIL came in and got p0012 intake cam timing. I never removed that cam, only exhaust to do the valves. I did remove the vanos gear, maybe that's it?

Anyone have ideas?

Edit: just did reading on the situation. I did new oil and filter. I'll check the vanos solenoid when I get back and the check valve

 

Check the timing again...when i did an N18 engine, the intake vanos kicked it back and i had to reset it. may not be the case but confirm.

 

Well, yesterday I pulled the check valve and cleaned it, simple design, ball, spring. No debris came out, all clean.

Removed vanos solenoid on exhaust, clean, normal.

Vanos solenoid on intake had debris on it! Not much, but on the external hard drive screen, enough to make a difference.

So, I swapped em, intake for exhaust, bolted it all back up and went for a text drive. 40 miles (half backroads, half highway on cruise), not a stumble or peep. No codes, no roughness.

I'm happy.

Thanks everyone for your help and support.

 

That is wonderful...glad it's sorted out