C20XE Misfire

[Mieran]

. (http://www.migweb.co.uk/forums/engines-transmission/522405-random-c20xe-misfire.html)

[scott.parker]

Is it a dispack engine? They give issues like this as they start to breakdown etc.

[Spudly]

You said on your other thread that plugs are brand new GM ones, theres your problem, fit some NGK3330's in there and see how you get on, might also be worth trying another coilpack just to rule that out, but after my experience with them, it sounds like plugs!



Heres the thread from when i was having misfire issues recently..

http://www.pngclub.com/forum/showthread.php?197820-C20XE-intermittent-misfire...&highlight=

[Alex J]

i had a misfire, it was the gaps in the plugs, and the ****ty cheapo leads the problem, booooooooooosting fine now!!

[Southie]

Also have you done a compression test, with it being new build something may not be right.

[Mieran]

I've put NGK BCPR7E in today after a search everyone recommended them for a c20xe but they made no difference.

Leads are next to try, going to order some from autovaux tomorrow.

Southie, engine hasn't been rebuilt, its exactly same as how it came out of the calibra.

[Mieran]

Since last post I've fitted another Bosch coilpack, different air flow meter, and Bosch leads. But its still the same.

I've noticed something else today which makes me think its what causing it, battery is not charging. I ran it for a few mins and when turn it off and tried to start it battery was completely dead. When I charged the battery up with my other car and put it back on the Nova, I put a multi meter on it and its showing between 11 and 12v.

So how do I check if its battery or alternator that is at fault?

[Mazz]

That should be showing ~14.4v iirc, try anther battery would be the easiest solution i'd think...when I killed the alt on mine at Oulton, while driving home the EM light lit up as it was reporting low voltage at the sensors, have you got the EM light wired up?

[meritlover]

low battery power will cause the fuel pump to be slower, the fuel pressure to be lower, the inj duration to be shorter and the sparks to be weaker.

this would all be a very possible cause for a miss fire.

have someone check it out.