changed plugs but still missing...HELP

[jasonmi]

Firsty i done a search and can't find what im after.
I got a VT SS 5.7 and noticed that it was starting to miss, i had the car for 40 000k's and hadnt changed the plugs so i assumed it was them, took them out and didnt seem too nasty(they were ACDELCO) and put genuine holden ones in. I took it for a drive and it was still missing, some times its ok but then other times its still missing. That makes me think the leads need to be replaced, is there anything else that could be causing this if its not the leads???
I'm taking the car in this saturday for the 200k service, is there anything that i should pay particular attention to or just the routine service?
Anyone got any advice, cheers
Jason

[Big_Valven]

I heard yours has developed a miss... could get them to have a look at it.

[jasonmi]

I heard yours has developed a miss... could get them to have a look at it.

???whos them??

[Martin_D]

Does it have aftermarket leads?

[jasonmi]

Does it have aftermarket leads?

no it doesnt......standard

[whitels1ss]

Sometimes if you open the bonnet and have a look around the engine whilst it is running in the dark (night time,)you can see sparks tracing from the leads if they are bad.
If you can see a little sparky light show a new set of leads would be the next thing on the shopping list. :)

[jasonmi]

Sometimes if you open the bonnet and have a look around the engine whilst it is running in the dark (night time,)you can see sparks tracing from the leads if they are bad.
If you can see a little sparky light show a new set of leads would be the next thing on the shopping list. :)

if its not the leads....any other suggestions

[whitels1ss]

could be coils, fuel injectors, could be.....
Sorry mate, no simple answer, I would start by having a look at it running in the dark with the engine covers off because as I said you can often see a spark shorting through in the dark.. Otherwise you might have to take it to someone to get it checked out.
Which part of Adelaide are you?

[Evman]

First thing that came to mind was a buggered coil, but I haven't heard of these buggering up before. Injector is definitely an option. Always go through the 4 things an engine needs;

Fuel
Air
Ignition
Lubrication

It's obviously not going to be air or lubrication (hopefully), so it can only be fuel or spark...

[jasonmi]

Which part of Adelaide are you?

im in norwood

[whitels1ss]

Mate, even if you can't see anything I reckon a new set of GENUINE Holden leads will be your next obvious step if they have never been changed since you have had the car.
If that does not sort it out I reckon I would not mess around with it anymore I would go and see Street Tuna as I believe he is about the best LS1 tuner in Adelaide. :)

[jasonmi]

Mate, even if you can't see anything I reckon a new set of GENUINE Holden leads will be your next obvious step if they have never been changed since you have had the car.
If that does not sort it out I reckon I would not mess around with it anymore I would go and see Street Tuna as I believe he is about the best LS1 tuner in Adelaide. :)

thanks mate, will see how i go

[whitels1ss]

What did you do with your auto trans?

[ls1vt209]

I would be checking that your leads are plugged back in right, especially on the coil side of things. I have seen a few times that people have taken the leads off to change the plugs but have not put them back on all the way either on the plug or the coil and has caused the problem you have described. If after checking them it is still missing I would probably change the leads anyway, not an expensive outlay really and if you have never changed them, then who knows the last time they were done (if ever). Also check your PCV valve and the breather system for any vacum leaks especially the join at the back of the manifold to make sure it has not gone soft and either caused a leak etc.

Just a few things to cancel out for starters.

[jasonmi]

What did you do with your auto trans?

trans got rebuilt by the guy you recommended (jamie) did an awesome job at a price $800 cheaper than any where else in adelaide.

[whitels1ss]

Thats good to hear mate :)
He is quick too!

[smokey777]

whats best plugs & leads for LS1

[OPTIMUS]

Id go some MSD 8.5mm, best/cheapest place to buy is on ebay...

[RRossi]

I have the same problem, but I have new leads and plugs (3 months old)

am getting it looked at tommorow so hopfully I will know whats wrong with mine, but just to add there are no enigne light coming up at all, will let you know what they find wrong on mine........gulp........

RR

[jasonmi]

I have the same problem, but I have new leads and plugs (3 months old)

am getting it looked at tommorow so hopfully I will know whats wrong with mine, but just to add there are no enigne light coming up at all, will let you know what they find wrong on mine........gulp........

RR

look forward to hearing what the issue is, hope its not too bad
cheers mate

[Martin_D]

Its either a broken lead, a lead not clipped on properly....or if its a light load miss, an O2 sensor. Whatever, it will be a simple fix :)

[RRossi]

Well

took it to metro motors to have a look at it and $120.oo later I have found out there is nothing wrong with the car and there are no codes but my maf is showing a code and that is my problem??? WTF:goodjob:

already have been to Chippys all is good with the tune as I already new, have had the car for 1 year now and no problems with the tune just wanting to make sure I check every posibilty out, so Now

I will be looking at the plugs and leads even though the plugs are 2 months old and the leads 6 months old. Holden were going to charge me $350.00 for inspecting the leads?? (not having a go at holden at all, they need to make money too just not from me)

and see what I come up with it has also developed a whistle now?? after chip/holden have looked at it?

meh just want to get to the bottom of this, its sad really that if a car isnt showing a code there is nothing wrong with it in the eyes of a dealer, even though it is running very bad.........technolgy is cool :bawl: , will keep you guys updated

sad thing is I could have bought two o2 sensors for the price of Holden telling me ther is nothing wrong,lol


RR

[BLACK 346]

and see what I come up with it has also developed a whistle now??

I think Ultra tune are good with whistle's, they sorted me dads
Shtatesman without to many problems.

[RRossi]

I think Ultra tune are good with whistle's, they sorted me dads
Shtatesman without to many problems.


lol sounds funny hey:rofl:

First off apolgys to the orginal poster I did not indend to hijack your thread

but hear goes


well this afternoon I checked all the plug leads to make sure they were conected, all were good, i even tunred off all the lights to see if any sparks were jumping from the leads all was pitch black, I took the TB off cleaned it and the tps,IAC put everything back even put back my kostecki intake to see if there would be any diffrence,

still have the whistle and misfiring, but heard a new sound like a tappet/valve/valve spring/rocker arm.

so my next point of call will be to take the rocker covers off, and check the valve train, is this possible that a valve spring may have cracked? causing a missfire and no code to come up? or am I just dreaming??

any help would be appreciated

RR

Oh and I have checked all the pvc lines inc at the bcak off the motor all is good, found that out from reserching the forum as that may bring up an O2 code.

RR

Well I took my rocker covers off and inspected the valve train everything seems to be ok, all I can do now is repace O2 sensors

check them out

then if that dosnt fix the problem I will have to replace coils and cam sensor, it is very frustrating and I can see this costing me an arm and a leg to get it sorted......


RR cant wait to get to the bottm of this, oh and to replace the o2 sensors can I do that on the floor? or would a hoist be better?

cheers

RR

[jasonmi]

update:
have changed my leads and plugs, new battery, cleaned throttle body and now the car runs like absolute shit. it was only missing ocasionally before and now its missing all the time, i know my o2 sensors have been an issue with the engine light coming up occasionally, but i have had that for over a year and its never been an issue, so im thinking changing o2 sensors, could this be the problem? if so why has it gotten worse with new plugs and leads???
thanks for any help

[macca33]

O2 sensors would be the next thing, I spose......But, and I hate to say this, why guess and possibly purchase parts that do not fix the problem. My advice would be to take it to a COMPETENT workshop - LSx specialist even better - and get it checked thoroughly.

Cheers and good luck,

Macca

[KCB50L]

Did you remove the throttle body completely? It sounds like a PCV/ breather line problem.

[jasonmi]

Did you remove the throttle body completely? It sounds like a PCV/ breather line problem.

no didnt remove the throttle body,
my mechanic is a experianced guy with ls1's and i just cant understand why it would have gotten worse

[VX2VESS]

O2 sensors would be the next thing, I spose......But, and I hate to say this, why guess and possibly purchase parts that do not fix the problem. My advice would be to take it to a COMPETENT workshop - LSx specialist even better - and get it checked thoroughly.

Cheers and good luck,

Macca

or get the codes checked then buy what it needs if anything shows up in sensors. faulty O2;'s will show up.

[jasonmi]

i just checked all the leads and it seems that one of them is coming loose on the plug end, hence why it has run like absolute shit, the others are secure but one will come off with the lightest touch, cant get it to clip back on....any suggestions?

[ls1vt209]

If your mechanic purchased the leads andput them on the take it back to him. If not then see if you can ever so gently close the end up so that it will fit snug on the plug end.
I did this with a pair of pliers as I was having the same prob with one of my leads.

[daskip]

my VT SS Series II developed a miss aswell

new
- 9.0mm QLD Ignition Leads
- Standard Holden Plugs ( Gapped 1.3mm ) For LPG/Petrol

my lpg stopped running after i did the above , then it started working again now its stopped again

car still has a miss , ive cleaned out the throttle body , airflow sensor at the airbox aswell.

COLD compression test showed 150 across all 8 cylinders.

only thing i havent tried is new o2 sensors

[jasonmi]

my VT SS Series II developed a miss aswell

new
- 9.0mm QLD Ignition Leads
- Standard Holden Plugs ( Gapped 1.3mm ) For LPG/Petrol

my lpg stopped running after i did the above , then it started working again now its stopped again

car still has a miss , ive cleaned out the throttle body , airflow sensor at the airbox aswell.

COLD compression test showed 150 across all 8 cylinders.

only thing i havent tried is new o2 sensors

i also changed my battery as if its on its way out low voltage can effect the firing.......

[QNLOOK]

If you guys think you may have a problem with just 1 cylinder then I would suggest that while the car is idling unplug 1 injector at a time and then plug it back in and look for the 1 injector that doesn't seem to make any difference to the idle (or very little difference). At least that way you can then narrow your problem down to 1 injector, coil, lead or plug and then swap them around until you work out exactly which component has failed. And like tuna and others have pointed out the o2 sensors can effect light load cruise in a big way but I would think that the fuel trims would reflect a buggered sensor and would be easy enough to pick up by a tuner. Other than that I wouldn't know anywhere else to look and would prob just burn it. lol, don't tell the NRMA I said that

[jasonmi]

have finally found the issue, after putting on new leads and leaving the workshop my car was running the worst its been, i couldnt go back cos i was late for work. I later found that the rubber grease that was put on the leads (which i didnt think was normal, but the place that we got them from said to do this) was causing the leads to slip off the plug, so we cleaned the grease off using some chalk and then found that plugs were tracking and sparking against the metal 'boots'. We then took the boots off and the car was running much better but still missing slighty under 2000rpm, which lead us to the throttle body sensor and air flow meter, air flow meter was ok but it had lots of debris in it, we cleaned it and saw an improvment but still a light miss under light load and rough idling,it was running better than ever with no miss at wot, which then lead us to the o2 sensors as when the car is in open loop throttle is maxium and no fuel issues but in closed loop (idle/light load) its missing due to fauly o2 sensors causing a 'lean' feedback message to ecu causing more injection which is causing it to run rich under light load and idle hence the miss. So replacing o2 sensors in next day and we feel pretty confident that this will eliminate the missing all together.
Any comments/opinions??
Jason

also is it worth resetting the computer, to get rid off all the error codes the o2 sensors have thrown??
cheers

[daskip]

if you can get your hands on a scan tool to plug into the odb2 plug it can tell you what readings your o2 sensors are feeding back to the ecu.

the miss that my car had was due to a faulty lpg injector flowing lpg into cylinder 1 even when shut off and fouling up the plug.

id use a scan tool before u fork the cash out on new o2 sensors to actually see if they are feeding back slow ( lazy ) or are feeding back quickly ( normal )

[jontall]

Firsty i done a search and can't find what im after.
I got a VT SS 5.7 and noticed that it was starting to miss, i had the car for 40 000k's and hadnt changed the plugs so i assumed it was them, took them out and didnt seem too nasty(they were ACDELCO) and put genuine holden ones in. I took it for a drive and it was still missing, some times its ok but then other times its still missing. That makes me think the leads need to be replaced, is there anything else that could be causing this if its not the leads???
I'm taking the car in this saturday for the 200k service, is there anything that i should pay particular attention to or just the routine service?
Anyone got any advice, cheers
Jason

Mine was missing and changed the plugs also, but it didn't help. It turned out to be a bad front oxygen sensor. (No check engine light came on.)

[jasonmi]

ended up being faulty o2 sensors, car runs like a dream now