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vr rough on take off, keeps pushing up to speed.

bombadore23

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vr slugish on take of every now an then, car vibrates bad as f%$k some times, the problem seems to come an go, revs decrease an increases . was told it could be coil, wat else could cause a problem like this, how do i test the coil without getting third party involved? help a brother out:bang:
 

greenacc

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hey brother , 2 easy ways to test a coil. 1st way is without touching coil - wait until dark, open bonnet and start engine. look for sparks aorund coils and leads. if you can't see any try revving engine while watching, and check again for sparks. 2nd way is remove the coils and check resistance across primary and secondary terminals. Got a workshop manual ? If not seach for primary resistance or something - there's plenty of talk on coils on here.
 

kopper69

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Hi bombadore23,

Welcome to the site. Can you describe the problem a little more. Is it missing under load? Does that sound like your problem?

A miss or rough idle is caused by a cylinder not firing. The most common cause is a spark plug lead. They will usually fail completely, causing a miss most noticeable at idle, or fail under load, meaning when the engine is working it will have a seemingly random misfire. So start with the spark plug leads. They are cheap and easy to do. Wouldnt hurt to do the spark plugs while you are there.

The coils produce the high voltage for the spark, and so can also be the problem. They are more reliable and more expensive, so your best off not worrying about them unless the leads dont fix your problem. Using a multimeter you can measure the resistance of the primary and secondary of the coils, its fairly easy to do. If it is an intermittent problem though, the coils will probably measure fine.

Worth checking error codes too, instructions are in the how-to section. - Start with this!

It could be the IAC valve too. That controls the idle. If that was playing up you may get an error code.

The engine could be flooding too. Check the fuel pressure regulator. There is a vacuum line coming off it. If there is fuel in the vacuum line the engine will flood.

Could also be a loose vacuum hose. Check for any deteriorated hoses or loose hoses, especially if you have been working around the engine recently.

Actually grab a gregorys manual if you dont already have one. They would have a better check list with instructions on checking each. Probably your best bet if your still having trouble.

Let us know how things go
 

bombadore23

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wat exactly am i looking for with the sparks? should they all spark? wat determines the fault with this?
 

greenacc

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hmmm, yes, if your engine is running properly each spark plug should be sparking - but you should not be able to see it. What I was saying is that if you have a dead coil or lead, the insulation on the 'rubber' leads or the plastic on the coil can break down, the sparks will come out the crack in the lead, or out the coil. If you can see any sparks from either of these will your engine is running it means you have a problem, and need to replace the faulty parts. As Kopper69 said its usually the leads that die first, but see what you can see.
 

bombadore23

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yeah its missing under load,on take off an wen accelerating up hills, but every now an then while cruzing it'll start shaking the car up,feels nasty.the error codes r cuming up good, where is the iac valve located?wats it look like?where abouts is the vacumm hose located? been doing a bit of work on the car lately,maybe couldve knocked hose loose,i done oil changes an new radiator few weeks back.

a friend had the car tested last week wen first noticed problem while i was at work,they tested the 1st of the 3 coils the read 8.sumthing and sold her a new 1 witch didnt seem to do much. wat else could cause the high reading? could the others need replacing or still start with the leads?

cheers for the advice boys,
 

bombadore23

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cheers mate,i'll go c wat i can see now an get back to u
 

bombadore23

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no sparks cuming out at idle, dont wanna **** the neighbours of too much to excellerate it to much, but will check it earlier tomorrow nite an get back to u,cheers
 

kopper69

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Start with the leads. Get them done and we can move on. Checking the engine while the engine is running is best done at night. You are looking for sparks as greenacc said. If a lead is faulty it will spark to a grounded part of the engine and you will see a bluish glow where it is sparking to the engine.

To test the coils you need to remove them, one at a time. Each is held on by two bolts. You measure the primary and secondary resistance of the coils. Gregorys manual gives the exact specs that each reading will need to be between. If you have a multimeter take the measurements and let us know what they are and we can tell you if they are good or bad.

So youre saying you put a new coil pack in because you thought one was faulty?

If it didnt fix the problem the one that you replaced is a good coil pack. It could also be the DFI module (Black box) that the coil pack sits on.

Start with the leads and plugs and we can go from there.
 

bombadore23

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last wk a mechanic tested the coil ,1st coil tested higher than others.an everything sparked an said it needed replacing,brought it,replaced it with new 1 an problem still there.

about a month ago i had CAS replaced,code 46 flashing. could sumthing be goin wrong with that to cause such a problem? maybe sumthing loose or not tightened properly?

could the tourqe converter b causing this problem too?

thanx heaps for the help an advice m8, much appreciated,
 
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