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Lodgy
P Plater
68 Posts
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 Posted - 18 Jul 2010 : 10:02:15 PM
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so the commodore was up and running fine, just a few noises which were more of annoyances than actual problems, but now after wiring up an amp so i can ignore these nasty noises ( i know it is not the best idea) the car has an extremely rough idle and will misfire. Z
It will choke and shudder more than any of my bush bombs when under load, which is not a constant problem, some times it decides to run fine.
When in park, it idles smoother, just not much smoother.
Besides that the whole car feels very sluggish compared to what it used to.
I have a feeling it may be am electrical problem as when idling sometimes the headlights will dim when it is on the verge of stalling.
Sorry for the long post as i'm just trying to give as much detail as possible, any help will be greatly appreciated as i am going to need the car to get to school in the morning.
Thanks for your time
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hsv_babe
Fully Licenced
269 Posts
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Posted - 18 Jul 2010 : 10:14:49 PM
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| What kind of condition is your battery terminals in? And what volts is your altenator running at? |
I'd gladly push my holden than drive a bloody ford! |
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Lodgy
P Plater
68 Posts
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Posted - 18 Jul 2010 : 10:22:57 PM
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thanks for the fast reply, the positive terminal is the standard one, it is a V6 by the way, and the negative terminal is made of some soft metal? as in if i belt it with a hammer it will dent it.
i do not know what the size of the alternator is, for all i know is it's standard.
I have had the amp in for 200kms of driving, the first 150 without a problem at all, 150 - 170 with possibly a problem which i did not notice and then the last 30 with a definate problem.
I have the battery on the charger now and it was reading about half on the gauge when i started and is down to about a quarter now. |
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Lodgy
P Plater
68 Posts
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Posted - 18 Jul 2010 : 11:12:11 PM
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ok i done a quick test because i was bored,
I opened my bonnet and revved the motor using the top of the throttle body, as it is dark i could see the spark travel through the lead to cylinder number 5, does this mean that it is buggered? |
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Mechknight73
National Driver
1001 Posts
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Posted - 18 Jul 2010 : 11:26:32 PM
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| It sounds as if the plug lead may well be knackered. Usually the only way you can see the spark in a lead is if you disconnect it from the spark plug, stick a screwdriver down it and sit it near a decent earth. The fact that it is misfiring under load (as in in gear) give a big clue. Buy a new set of leads, because if one of them is stuffed, no telling when the others might spit the dummy as well. If it still runs funny after changing leads, check the spark plugs both for fouling in the electrode, and cracks in the ceramic insulator |
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Lodgy
P Plater
68 Posts
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Posted - 18 Jul 2010 : 11:29:55 PM
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| thanks for that, i should be able to make the 10 minute limp into autobarn tomorow morning, how much should a set of leads cost? the ones i have now are bosch maybe 8.0 leads, black with yellow writing |
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VNSVLE
Forum Moderator
1316 Posts
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Posted - 18 Jul 2010 : 11:56:39 PM
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| I would also suggest a set of NGK plugs while you are going. |
What's the difference between understeer and oversteer?
Understeer is when the driver is scared.
Oversteer is when the passenger is scared. |
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Lodgy
P Plater
68 Posts
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Posted - 19 Jul 2010 : 01:26:12 AM
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for just a quick fix could i use any spark plug lead with the commodore heat shield on the end?
because i have a fair few lying around that are in good condition just not a whole set.
Does brand and size matter? and will using a different lead cause any problems? thanks |
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Mechknight73
National Driver
1001 Posts
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Posted - 19 Jul 2010 : 09:19:01 AM
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| In theory, yes. Most of the differences between spak plug leads are to do with how long they are, and what's connected to the ends. Study how the original lead is put together, and measure the one you want to switch it for before you take anything apart. |
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Lodgy
P Plater
68 Posts
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Posted - 20 Jul 2010 : 9:28:14 PM
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thanks for the help, changed the plugs and leads and it still didnt help, the car isnt making any funny smoke but i can definately smell petrol whilst driving with my window up.
I checked my fuel reg and it seems to be working fine and replaced the little vacuum hose, cost me nothing from my mate at autobarn :)
any suggestions on what i could try next? preferably something that doesnt cost much at all. |
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Mechknight73
National Driver
1001 Posts
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Posted - 20 Jul 2010 : 10:50:18 PM
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| Suspect that it may be a faulty ignition module. Check the connector to the coil packs, and if at all possible, borrow a good one. If it runs normally with a known good coil pack, then this is likely your problem |
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Lodgy
P Plater
68 Posts
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Posted - 22 Jul 2010 : 10:32:18 AM
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yeah thats my next plan, the set of coils im using now are from a VR, my mate brought new ones when he washed his engine bay with a pressure washer and these ones were apparently water logged, that was about 16 months ago and for some reason they work fine now. Or they did atleast
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Lodgy
P Plater
68 Posts
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Posted - 22 Jul 2010 : 1:56:26 PM
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alright decided id check for error codes, i was abit iffy about it but in the end i got a code 12, so all should be good right?
after that i reset the computer and still didnt change anything.
had a listen to the injectors, number 6 has a lower sound then the others, less tinny perhaps. But im not really in the mood to go and buy new injectors when they definately wont be the cheapest thing. |
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Mechknight73
National Driver
1001 Posts
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Posted - 22 Jul 2010 : 2:49:04 PM
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| Not that I know about injectors all that much, but ask about the seals on them, check for leaks (you did say there was a distinct smell of fuel) There's a slight chance something on the injector lines is leaking. If you're lucky, it's some stupid o-ring that's perished and split. Even before you take anything apart, just check to see if they're all tight in the engine. Each one of the injectors has some kind of wiring on it, so I assume it's some kind of solenoid. Make sure that's secure too, it might be "just hanging" which would explain the coughing, spluttering and misfiring. Just speculation, but checking all this costs you nothing but time. |
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Mechknight73
National Driver
1001 Posts
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Posted - 22 Jul 2010 : 2:56:58 PM
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| Checked the manual, and there are two o-rings on each injector; one on the fuel rail side, and another on the manifold side. Apparently the injectors are held in by clips. If you do go into depth with changing them, it warns to release the fuel pressure and disconnect the battery first. Before you dismantle anything, shine a torch on each injector while the engine is running, and then rev it as well. If there is a leak in one of the injectors, it should stick out like the proverbial. |
Edited by - Mechknight73 on 22 Jul 2010 2:58:43 PM |
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Lodgy
P Plater
68 Posts
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Posted - 22 Jul 2010 : 7:53:21 PM
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| yeah thanks for that mate, i'll check the injectors properly tomorow, i might also grab a few different sizes and lengths of vacuum hose and then replace everything and see if that helps |
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Mechknight73
National Driver
1001 Posts
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Posted - 24 Jul 2010 : 3:30:13 PM
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| I forgot to mention, check the fuel lines from the tank to the injectors, and make sure your fuel filter's ok while you're at it. The fuel filter on a VN is a metal canister about 75mm in diameter. Remember to point it away from yourself when you change it unless you want a petrol bath. |
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Lodgy
P Plater
68 Posts
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Posted - 25 Jul 2010 : 3:10:08 PM
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| yeah ill give that a go now, thanks. I just checked my coil packs on a multimeter (VR coil packs) one read 6.04 another read 6.12 and the last one read 5.9, i know the difference is not much, but is the low reading enough to cause it to misfire? |
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Mechknight73
National Driver
1001 Posts
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Posted - 25 Jul 2010 : 4:18:20 PM
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| Can't say for sure, but if you had one you knew was perfect, and it was still chucking a wobbly, then you know you've got more probs than just ignition. Any difference in output from the coils might cause it to misfire under load, but can't give you a straight answer as to how much difference it makes. If it was a huge difference, you'd see it on the plugs; a plug firing properly has x amount of carbon on it. A cylinder not firing at all may be slightly damp with fuel. However, a plug firing some of the time may look somewhere in between, owing to the dismal amound of spark |
Edited by - Mechknight73 on 25 Jul 2010 4:21:38 PM |
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Lodgy
P Plater
68 Posts
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Posted - 26 Jul 2010 : 7:57:55 PM
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thanks for that mate, i'll check the plugs tomorow, it should be easy to see the difference as they are new plugs, you really are a big help.
Thanks again |
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Mechknight73
National Driver
1001 Posts
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Posted - 26 Jul 2010 : 9:43:03 PM
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| I'm at a loose end due to being unemployed at the moment, so at least I can be useful to someone. This idling is driving me nuts! |
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Lodgy
P Plater
68 Posts
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Posted - 01 Aug 2010 : 8:07:48 PM
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| finally got sick of it and grabbed a second hand coil pack from the wreckers, $30 later and it's running great again :) thanks for all the time and help, even though it was one of the first things mentioned. |
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Mechknight73
National Driver
1001 Posts
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Posted - 01 Aug 2010 : 10:26:14 PM
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| Although in the process, you've fixed a few more potential problems. The plug leads might have masked thr real problem, had you not replaced them |
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Lodgy
P Plater
68 Posts
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Posted - 02 Aug 2010 : 12:15:35 AM
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yeah im sure they were just about due anyway, but yeah i also done things like clean the IAC and throtle body, and also ran some injector cleaner through it, i wouldn't of even bothered if i didnt have a problem.
thanks again |
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