Missing on one cylinder

[ozfreerider1]

Hi all. Ive changed spark plug, lead, coil, what sugestions would you have for the next thing also how do you pull out a injector, I guess they dont screw in, Ive read afew things on here but I just want to check it thanking you
Sweet shock

[ephect]

how do you know its missing on 1 cylinder? what are the symptoms?

the injectors are held on by the fuel rail, i know on the ecotecs you need to remove the upper intake manifold to access the bolts to remove the injectors, im not too sure with the buicks setup.

[soop]

Just unbolt the fuel rail and pull the injectors out.

I've a feeling I've got some VN injectors floating around in the shed somewhere.

[ozfreerider1]

Its missing because I checked the plugs and found which one it was, Thanx for the info, The symptons are, start motor, it idles good for 15 seconds then stops firing on the same plug every time, theres fuel on the plug no 1 according to the coil

[ozfreerider1]

I have also changed plugs and leads from different cylinders

[acarmody]

Could be a dodgy coil pack.

[ephect]

Could be a dodgy coil pack.

my thoughts exactly, try swapping coil packs around to see if it follows the coilpack

[hako]

If it was a bad coil it would be felt on the other plug the coil fires as well I think....

[ozfreerider1]

What are the odds of a new coil failing pete

[ephect]

very true, but it costs nothing to swap, and rules it out.

[pecksterism99]

My VR had similar problem. Was due to failed oxygen sensor causing a very rich mixture. For some reason this caused the #1 plug to foul. However, it would take a few weeks to foul, not 15 mins! But your issue does sound mixture-related. Have you checked for fault codes?

[MR.HG]

I've a feeling I've got some VN injectors floating around in the shed somewhere.

ahh you live in brisbane too? everything is floating in my shed atm lol

a coil pack shouldnt cut out at 15 seconds..getting any fault codes?

[ozfreerider1]

I got a reading of 13, 16 so Im checking out the 02 sender, and temp sender

[ozfreerider1]

Sounds alot like pecksterism, It comes and goes sometimes takes the next day since i changed the coil

[ozfreerider1]

Ok I changed the plugs, leads, coil, injectors and still ran on 5 cylinders, But
I took it for a drive and switched to gas after about 2 ks on petrol and after 1 k it fired on all cylinders and so far still going fine, Ill change back to petrol in a couple days and see what happens. Can anybody explain why thanx, ps It was the same cylinder all the time.

[db_notso]

swap coil and plug and lead with opposite cylinder to confirm fault doesnt follow swapped parts
then its either an internal pressure issue OR injector OR injector signal

remove injector replace or recondition...
check terminals that plug to that injector arent opened up inside the plug OR bent over inside the injector

after these no fix next is a compression test..

[pecksterism99]

Your fault code of 13 indicates no signal from the oxygen sensor.

Did you check the leads/plugs to the sensor and the sensor itself?

I suspect your VR runs OK on gas since gas is "dry" and a too-rich mixture will not foul the plug, unlike petrol.

BTW - In my case, three mechanics (including a Holden dealership) said the fouling plug was definitely due to valve stem oil seals and I'd need a reconditioned head - so goodbye $2,000 plus ... but since I fixed the oxygen sensor, the plug has never fouled again, and fuel consumption improved by about a third!

[IBLOWN]

Check the injector by removing the electrical connector while its running.

[db_notso]

if it only does it on petrol and not on lpg
then this indicates combustion and spark are probably ok leaving fuel to that cylinder
suspect dodgy injector to that cylinder
OR buggered plug on that cylinder...

[ozfreerider1]

Sometimes it fires and sometimes it doesnt on gas or petrol, If i drive with the rev,s above 1500 when its not missing its ok till I backoff then it starts to miss, keep the ideas comin, Im waiting for a a compression gauge from ebay thanx

[ephect]

have you ran any more tests per members posts, if so, what else have you tested, and did it or didnt it work?

just so we can start narrowing down all the possible options

[ozfreerider1]

Ok first thing I did was checked plugs, No 4 was fuel wet, Changed all plugs, still the same, changed the coil pack, it started to fire fine for a while then I tried the next morning, It started fine for a couple minutes then lost a spark again, Spark would come and go depending on revs (5spd man), Changed injectors (all parts new) Started and still no spark, took for a drive and changed to gas I took it for a drive and switched to gas after about 2 ks on petrol and after 1 k it fired on all cylinders and so far still going fine, Ill change back to petrol in a couple days and see what happens. Can anybody explain why thanx, ps It was the same cylinder all the time. Finally next day on gas and fuel it went back to fire , no fire ,Im gonna check the plugs again

[ozfreerider1]

Ive been told it wont be the oxy sensor by a few people but i did read where one bloke on here said he's was similar and was oxy, So Ive spent abit so far, so I thought I'd sus it out abit more before spending more cash.

[db_notso]

so lets see here
if you clear codes and drive codes come back?
" 13, 16 so Im checking out the 02 sender, and temp sender "
with these codes replace o2 sensor/s, they have a lifespan about 160,000kms heated type, 80,000kms two wire type (non heated)
they get clogged up and read wrong normally causing multiple cylinder problems as air/fuel mix then incorrect
this o2 code can be set by old sensors soem people will lightly sand the outer face of sender to get another couple of months out of em (not recomended)

temp sender code can be same
-old senser; or loose terminals on plug at sender; or dodgy sender...
unplugging it when fault starts happening (with engine running ) can eliminate temp sender
-unplug (temp sender) when its misfiring at idle if miss goes away (miss because of this would resemble only a rough idle not complete misfire)
then its an incorrect siganl from temp sender~!


when you drove it misfiring on petrol... you changed to gas
then after awhile (2kms) it came good? this would indicate either a problem with fouling of spark plugs
is either mixture of fuel wrong (would affect multiple cylinders)
OR spark plug gap size(reduce gap to 1.0mm and retry) ; or plugs heat range/condition(check plugs suit lpg heat range AND petrol) ; petrol injector sticking open after firing (causing wet plugs after sitting a while hard start is indication of leaky injector; you may also get some smoke on start up after sitting a long time)

so replace plug and recon injectors is my bet (petrol injectors that is)

[ozfreerider1]

Is there any trick to remove o2 sensor, Ive sprayed and busted 2 spanners thanx