LS1 still running rough after leads and plugs changed...

[faBReGaS]

Hey all. The SS is still running a bit rough after I changed the leads and plugs, but not as bad now. It only starts feeling rough once it has fully warmed up.. When I'm sitting at the lights it will shake a little.. And when I accelerate it jerks a tiny bit through each gear.. It's not that much but it's enough to piss me off and want it fixed... I'm going to changed the fuel filter next week but that's all I can think that would make it do that.. Any ideas??

[soop]

I've a similar problem.
Have you changed the o2 sensors as well?

My thoughts is that its either the fuel filter or the coils.

Hoping its the filter.

[GMMAD]

if its only once its warm it sounds like 02 sensors

[faBReGaS]

Ok.. Would the o2 sensors make it feel like a cylinder is misfiring??

[faBReGaS]

Oh and I forgot to mention my car is backfiring when I take my foot off the accelerator then backfires again when I put it back on...

[ARATIC]

Probably best just to go back to your tuner and get them to plug the tech2 in to diagnose it. Better than spending hundreds of dollars on parts which may or may not fix the problem.

The amount of people who replace the plugs and leads in their LS1 thinking thats the cause their misfiring or rough running problems is unreal

[soop]

well its a smart place to start.
I think it's a timing issue. So Crank angle sensor.

[faBReGaS]

mmmm the funny thing is that it was running rough after I got my exhaust but before the tune.. Then I took it to GM Motorsport to get it mafless tuned about 3 months ago and I suggested that maybe one of the Oxi's was gone.. But everything came up all clear so then I thought my exhaust had just thrown it out of its original MAF tune that was on it.. After about a month it started to run a tiny bit rough and now it's actually jerking through low revs once I've been driving for about 10minutes and it's fully warmed up.. I really can't be bothered driving all the way to Melton again just for the tech 2 .. My mates shop has a tech 2 so hopefully they can have a look at it there..

[ARATIC]

Sounds like it may be the oxy sensors if it started running rough straight after getting the exhaust put on. From what I've seen on the forums lots of people have had oxy sensor trouble after getting exhausts done, apparently it can be something to do with the sealant they use on the gaskets contaminating them.

If they haven't been replaced then it cant hurt to get new ones (apart from your back pocket...), and if its not the problem atleast you have new sensors. It may be worth talking to your tuner first though, as I think some tuners turn off the oxy sensor input in the tune.

[soop]

anyone had issues running the extension loom on VY's with extractors?

[m1chael1o1]

sounds like its about to explode and must be replaced with a LS9

[faBReGaS]

Getting it hooked up to a tech 2 next Monday.. Hopefully it's nothing too big lol cross your fingers boys!

[faBReGaS]

Hooked up the SS to a tech 2 and no errors came up iv changed my leads, plugs and fuel filter now and if feels like the car is getting worse. It's jerking more through gears as if I'm running on 6 cylinders now and shaking like a bitch when I'm stationary at traffic lights. Does anyone think it sounds like a fuel pump?

[wana s' charge stock vt]

i dont have a v8, but it dose sound like a dodgy coil.. mine used to work ok cold and play up once warm, i first noticed it missed sometimes under full load, then just slowly got worse n worse ..
ya could just try a second handy coil from wreckers and swap it over 1 by 1..will cost fark all..

also herd alot about what old mate said ^^^^^ about the new exhausts and o2 sensors getting blocked. (but i doubt that would cause missing on certain cylinder's)..

[L31GH]

hey mate, might not be the same issue.. but I had a split PCV valve line in my vy ss which made it idle like shit and jerk through the gears... just a thought.

[faBReGaS]

Thanks boys I appreciate the help.. I just want her running normally again

[crazzy-johno]

Hey man mines doin exactly the same thing but when you start her up hot. bloody annoying!

[ElectronicEddy]

Could also be a temp sensor on the way out making it run a bit rich. Ok when cold but when it warms up the sensor starts to fail and give false info.

[Mohi]

hi mate,, check the vacuum hose,, as if it backfired , the hose come off sometimes ,,mine did and it makes the engine to run rough and idle rough as well.....

[faBReGaS]

havnt been on here in a while.. ended up being the o2 sensors. i took it to 2 different mechanics and they both said the o2 sensors were fine. Spent about $2500 on new leads, plugs and even ignition coils.. still didnt go away. Then i took it back to where i got my tune done, GM Motorsport in Melton, and they had it fixed within 3 hours. It was the first thing i thought it was, bloody o2 sensors not fluctuating voltage, giving my computer false readings. Car is running like brand new now and so responsive seeing as though i changed just about the whole ignition system lol.

Thanks for all the help boys.

[Vt_vic]

ouch 2500 just to find that it was just the 02 sensors

[faBReGaS]

yeah it was quite a painful sting... but in the end my car needed it all sooner or later and its running magnificently now. When it runs as smoothly and perfectly as it is now.. really makes me want to take it off the market and just keep it for myself! haha oh well goodluck to the next owner when it ends up selling!

[xxaussiepridexx]

i am having a similar problem but its only running rough in gear at idle its not too bad when its in neutral. its seems to jerk for a second when taking off but is fine after that, the engine light comes on every now an then but it never comes on when its at the shop which really pisses me off as u could imagine.
its a 2000 vt ss 5.7. i was told that it is the vac hose that runs from the back of the throttle body to both of the rocket covers, apparently its a common problem with these models but unfortunately for me it wasn't my problem. once the car is in gear it seems to idle at around the 500 rpm an sometimes it gets even lower to the point where it feels like its about to die any suggestions would be great

[soop]

Change the fuel filter.
Could also be O2 sensors. Best to get a mechanic to check the codes, that will give you a slightly better idea.

[faBReGaS]

First step is like soop said.. Change your fuel filter because it's cheap and pretty easy.. When I took mine off i couldn't blow much air through it where as with my new one I could.. Even though it isn't rough on idle it still could be your o2 sensors.. Make sure all of your spark plugs are all tight and leads all on properly.. But from experience, take your car to a mechanic before you go crazy on trying to fix it yourself.. I spent heaps trying to fix mine after a mechanic said my o2 sensors were fine by just looking at them! Anyway Goodluck mate I know how crap it feels to drive your car when it's jerking around like that.