vt shuddering problem - plugs? leads? coil pack? help please..
been having problems with my car shuddering while driving on the highway and around town. it seems to lose power or has lack of power to even pick up speed...
its like having wet spark plugs, struggles to coast, you can feel the car shudder bad when goin uphill ect..
its got a new fuel pump as the old one gave up...could it be a pump problem? it too iseems to be playing up when the fuel gets to under a 1/4 of a tank it stalls...gotta pull over n start the car again.....
should i just send it to holden to look at and service??
thoughts?
Originally Posted by CV6Z
Have the spark plugs, connectors and coil pack, alternator and battery checked by an auto electrician or use a multimetre. Also check the temperature of your car, check thats its not running cold, or that its an overheating problem. A major service should be done every 50,000km. Worst case scenario you have a busted head gasket and pressure is building up in the engine. Try bleeding out any air. In that case don't waste over $1000 on getting it replaced, go to repco or supercheap, etc. and buy head gasket sealent/repair fluid, costs $10-$15 bucks.
blocked catalytic converter?
If computers have no doors or fences, who needs Windows and Gates?
Ive run into this problem myself. First thing you need to do - Go to supercheap and get a can of aerostart or start-ya-bastard.
What your doing is looking for vaccum leaks. WIth the engine at idle (max vacuum) carefully spray around these components, listening to hear if the engine revs up. Be careful, this stuff is flammable, and contains a high percentage of ether. Only need to spray a little bit.
Spray -
Seal between upper and lower intake manifold.
Seal around top of plenum.
Seal around IAC and Throttle position sensor
Back of plenum where vac hoses attach.
Back of left rear head where the vacuum distribution block sits.
Brake booster especially where the vac lines attach.
Vac hose under the throttle body - one goes to front right of intake manifold, the other goes to the back left head to the vac distribution block.
Joins between Throttle body and maf hoseing, and maf hoseing and maf.
No Rev ups ? Ok step 2.
pull all the spark plugs. Play close attention to the plug that comes out of #6 (closest to driver) if that plug is heavily oiled, replace the PCV.
Look for signs of lean burning - a whitish residue, powdery. Lean suggests blockage in fuel systems, though it is NOT definitive.
Replace plugs if necessary.
Remove and inspect plug leads, looking for signs of arcing. The rubber will burn under arcs, leavving a bluey ehite powder on the heat shields. Replace if any doubt.
At this point, replace the Coolant temperature sensor. It sits under the thermostat housing in the gooseneck at the top front of the block. It's cheap, $25 and can the source of a few hard to diagnosis problems.
Inspect your Coil packs. Look for cracking or heat ageing. replace if in any doubt. These are not so cheap. When a coil pack goes, they can often take the DFI out that they sit on. This unit basically triggers the coilpack to discharge, providing spark to the cylinders. If you lift of the coil packs, you may see heat ageing or discolorouration on the DFI contact plate. If you do, replace it. Burtons will sell you a set of coils and a DFI for $300.00
Still no resolution ?
next thing on the list is the cam angle sensor and the fuel systeem. The CAS has input on when the Coils fire, so your 'timing' can drift if it misbehaves. On the fuel side, check and replace your fuel filter, Clean the injectors (drop them off and check that the baskets in the end arent full of crap, and that all the seals are intact, rinse them in clean fuel, then rinse them in method and let dry. be sure to use re-assembly lube on the seals when re-assembling, stuffing these seals is a sure vacuum problem.), and also replace the fuel pressure regulator while the plenums off. It sits on the end of the fuel rail, and the regulator is held in by an internal circlip, on the broad face.
Next on the list is the complex stuff. The PCM - $88 from a wrcker - VT2 is only compatible with VT2 with same gearbox. With the pCM out (the passenger footwell) ensure that you don't have a water leak from the windscreen - dirt trails will be evident. The PCM will need a Tech with an OGBD scan tool to make the PCM talk to the BCM. it wont run without it.
Still no worky ? Welcome to my world.
This is exactly the same series of events i got with My VT2 and I've got to the point where it very very rarely hesitates, and only stalls because i have deliberatley retarded timing at idle (oversize Throttlebody gives big torque response when cracking the throttle).
Good luck - and if you find something that works please let me know.
Cheers
Oh dont assume that going to holden or a dealer will get it fixed. Not every device has a 'fault' code associated with it. In addition, if the PCM is misbeahiving, it may not record the fault codes anyway. Your best bet is an experienced auto electrician with a full engine diagnostic centre.
Cheers
Cracked coil pack.
Go to the wreckers and buy the coilpacks with the DFI module and just replace the lot.
Donating member
Sounds to me like a dud plug lead, coil pack or spark plug,.............. in that order.
Sounds like leaking vacum hose Check back of engine passenger side I think and under air intake. Usually fall off for some reason. Happened to daughters' car. Same symptoms, cheers Brian
I replaced the sparkplugs and leads to a "performance" sets, and it stopped it completely. Also check if the leads are properly connected, noticed mine weren't and its absolutely gutless and shuddery otherwise
Yes its lowered, yes it has stock rims, yes you can smell tyre smoke, so whats the problem officer?
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