Firing on ony 4 or five cyl's

[dinodog]

:bow:Help Having problems trying to fine the miss fire in our VT 3.8 seems to be fireing on 4 or 5 have replaced plugs and tested leads with oms meter and all seem ok.Car has just clicked 200,000kms ex cop car has been a good car apart from that fact. the fuelfilter will be next:bang: then the Coils can these be the bad miss that i cant find????? thanks guys and girls :w00t:

 

[beeks]

Change the leads(I know you checked them) but see how things run after changing them,it could be as simple as that.When were they last changed(including sparks)?

 

[accentstencil]

I agree with beeks. The last time I had a miss I checked the leads and they tested OK. I changed them anyway and the miss was gone. If your leads a very old it's a good idea to change them, they aren't very expensive. Also check plugs. If all that doesn't fix your problem then move on to things like checking coil packs.
Every time I've had a miss (3 or 4 times) it's been a bad lead.

 

[Don Sutton]

:bow:Help Having problems trying to fine the miss fire in our VT 3.8 seems to be fireing on 4 or 5 have replaced plugs and tested leads with oms meter and all seem ok.Car has just clicked 200,000kms ex cop car has been a good car apart from that fact. the fuelfilter will be next:bang: then the Coils can these be the bad miss that i cant find????? thanks guys and girls :w00t:

First a question.
1] Is it the same cylinders missfiring each time?
Yes means leads to those cylinders or coil for those cylinders or possibly injectors for those cylinders.
No means that something affecting any cylinder which could mean possibly crankshaft sensor or power to distributor pack or air flow sensor or connectors to any of the above.

Note Each coil (there are 3) fires two cylinders simultaneously. One cylinder is at the end of the exhaust stroke and the other is at the end of the compression stroke. Each coil fires once per revolution of the crankshaft. If the missfiring is from a set of paired cylinders then that narrows it down to the coil.

 

[VZCalZone]

have you got heat shields on. If so take them off and see if it fixes it. Sounds stupid but one of mine was dodgy after i changed plugs and leads.

 

[sno]

take her in to a holden dealer, have a tune up - includes plugs, leads, checking the points and coil pack.. mines doing the same atm.. just having hard time to find the time to take her in..

 

[dinodog]

Well ye not going to beleave this but when i got all leads and plugs replaced and still had the problem i got to taken the top cover off the motor just to see if the fuel rail was ok and check eveything thats there but there was all this paper and rags and stuff in and under the intake, like a little nest or something, well when i pulled the wire's that tell the injecters what to do there were no wires as what had ever been living there had eaten all of the wires that run the fuel line's and inecters and that so i fixed that then the other day i was at work and this big f----king rat jump out of the back of me car i said F_______K see that to me mate and he said F_____ dat so this is just to say RATS like the good ol'e Holdens too.

 

[accentstencil]

That's very unusual. Do you drive it every day or has it been sitting for a while. You wouldn't think a rat would like that sort of environment. Anyway is you car running alright now that you've found the problem?

 

[beeks]

Well ye not going to beleave this but when i got all leads and plugs replaced and still had the problem i got to taken the top cover off the motor just to see if the fuel rail was ok and check eveything thats there but there was all this paper and rags and stuff in and under the intake, like a little nest or something, well when i pulled the wire's that tell the injecters what to do there were no wires as what had ever been living there had eaten all of the wires that run the fuel line's and inecters and that so i fixed that then the other day i was at work and this big f----king rat jump out of the back of me car i said F_______K see that to me mate and he said F_____ dat so this is just to say RATS like the good ol'e Holdens too.

Whatever your taking,lay off mate.Sound's to me like you were a little bored when posting this bro.Try posting a genuine problem next time.

 

[summernats2010]

sorry to correct you beeks but i am a mechanic in south west victoria and i get these sorts of problems all the time generally farmes leave their cars in a shed near a haystack or something and rats ad mice chew all sorts of wires etc etc actually i have had to fix hetaers head lights etc etc but as for something living under the intake, well sounds a little suss to say the least