Misfire

Removed the airfilter box on my 3.0si to get to some wiring but had to move the car about 10ft (uphill) so i thought arr it should be ok. Started the car up moved it back, later on pushed it back (rolled down hill). Completed the wiring (angeleyes) reasembled everything with a new K&N air filter, now the cars running real rough and if i accelerate more than say 25% it starts firing on 3 cylinders and eng light comes on. Anyone any idea's
 
aliveankikin said:
Removed the airfilter box on my 3.0si to get to some wiring but had to move the car about 10ft (uphill) so i thought arr it should be ok. Started the car up moved it back, later on pushed it back (rolled down hill). Completed the wiring (angeleyes) reasembled everything with a new K&N air filter, now the cars running real rough and if i accelerate more than say 25% it starts firing on 3 cylinders and eng light comes on. Anyone any idea's

Any chance you dropped something in the air box?

or check the air hose that go in to the manifold system past the MAF/ throttle body as if its off, it could be causing it to run very lean!
 
Hey Dario, I stripped everything down (intake) & it all looks ok, did a (homemade) smoke test with no leaks that I can see. It seems like bt going onto 3 cylinders its like limp mode. I think I must have damaged something by starting it up without the filter & box but with the the MAF connected, maybe a lambda sensor. ECM like shows no2 sparkplug but it & the coil is ok. If i unplug the MAF sensor the engine does not stall. ????
 
If it runs fine with the MAF unplugged then your MAF is dead, most likely too much oil on the K&N which has clogged the sensor on the MAF.

You could try cleaning it, but be very careful as they are very brittle and easy to smash.
 
I don't think the K&N would be the problem, if you've only just fitted it and it's running rough straight away it wouldn't get covered in oil that quickly. Would be a gradual build up over time, especially if it's new, usually second hand ones that have been over oiled by the previous owner.
I would say it sounds MAF related though potentially. Have you cleared the fault codes now everything's back together and tried the car again, see if the EML comes back on? Any chance you could have damaged the MAF during the install, wouldn't take much to damage the wiring on it.
 
For all we know he dropped the MAF or let his dog chew on it, but its not unheard of for aftermarket filters to cause problems which is why i mentioned it :thumbsup:
 
Very true, although unless its been installed incorrectly it would be strange to give a fault straight away.
I would start with clearing error codes and go from there, and as Simon suggested cleaning the MAF would be a good idea....carefully though :wink:
 
Just cleaned the MAF sensor but no difference. Bought a BCable with software. Everything looked good apart from the voltage which is 11.2 volts. Not sure if this was because I had a fully charged battery & it had backed off. Need to check voltage at the plug on the coils when I find out how to
 
Update: Checked voltage at coils, all ok Bought 2 new coils & fitted them to No's 1 & 2 and at last everything back to normal. The only thing I can think of is the No 1 or 2 coil was on its way out and it was coincidental or I spiked the rectifier when I was wiring. Nothing showed up on the ECM though. Anyway its all good now but Ive ordered 4 more coils & I will refit the new iridiums. Not so sure about refitting the K&N air filter though, I got a new paper type.

Thanks for your suggestions & comments guys.........cant take the smile off my face, its like being a kid again lol
 
Sounds like you flooded it pal, when you start it and only move it a few feet and turn it off the cylinders are still full of fuel, it is a common issue, I have had the same loads of times, just let it rest or leave it ticking over it will clear its self.
 
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