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V6 ignition problems

Posted: Sun Dec 14, 2008 10:52 pm
by mjb
Been having some issues with the car the past few weeks. I've had about 10 misfires/stutters when cold over the last month or so, but the worst is the warm starting.

About half the time when the engine's lukewarm (having gone 300 yards to the shop on the way to work), it'll fail to start. The starter cranks but it just doesn't fire up. No "trying but not catching", there's just the sound of the starter. It'll start after about 5-10 seconds of cranking with no problems. Pushing the accelerator seems to help, but there's no evidence to say definitively

Another issue is after cold starting, the idle speed can jump to a solid 2000ish rpm for a few seconds.

All this has started over the past few weeks since the weather's been nasty so I'm wondering if i've got some condensation issues, perhaps around the plugs affecting the lukewarm starting, and in the throttle pot causing the idle surges and misfires?

Thoughts?

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 7:48 am
by steve_earwig
Find a forked stick, hold it loosely in both hands and move it about above your engine. When you feel some extra weight pulling it down it will be above the defective component.

Spray some carb cleaner though the stepper motor, spray your plug caps with ignition sealer, check the connections to your coolant temperature sensor, possibly measure same for resistance at a variety of engine temperatures, replace entire engine management system one component at a time, seek help from someone with a proper diagnostics machine and the ability to use it.

Good luck! :cheesy:

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 8:40 am
by Welly
Have you checked the leads and especially at the spark plug end? sometimes you can get oil welling up in one of the plug holes.

High tickover would probably point to TPS and/or throttle body (a good clean up should help) ?

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 1:54 pm
by mjb
The TPS, ICV and throttle body (which actually needs removing to get to the TPS) got cleaned a couple of months ago. I think the high revving could well be the TPS too. Might have a look to see if I can fabricate one from scratch for £2 instead of spending £200 down the stealers

I haven't actually even taken the engine cover off this car yet, let alone ripped the inlet manifold off to get to the top of the rear cylinders. Not something I'm too keen to attempt without a definitive goal in this weather either - as the temperature goes down the chances of dropping something somewhere bad gets high...

What's this "ignition sealer" stuff?

Also, does anyone know what the best plugs are for the V6? If I'm going to rip the manifold off, I may as well give them a change. The car was bought with full Peugeot service history, so I'm guessing I'm still on the original plugs in the rear bank ;)

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 2:12 pm
by Welly
The FTO 'we' had was fitted with Platinum plugs on the rear bank because the inlet manifold was in the way. The platinums were reputed to last 60,000 miles I think the normal plugs were 24 or 36,000 ??

NGK seem pretty good generally.

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 4:32 pm
by steve_earwig
mjb wrote:What's this "ignition sealer" stuff?
Umm, I can't really remember, the tin was red, if that helps. It's a kind of water-repellant coating, I think it was something like this

Spark plugs? I have some of those, somewhere.

Re: V6 ignition problems

Posted: Mon Dec 15, 2008 4:55 pm
by jasper5
Clean out the throttle body, as before, with carb cleaner and clean out the exhaust gas recirculating valve, EGR valve,this causes surging, misfires, and bad starting when warm, also, intermittant cutting out when it gets clogged up.

The best thing to do with plug leads like those on the V6 is to wrap insulation tape all the way down the lead from where they enter the plug hole.

Also, cover the coil pack with a plastic bag to keep out condensation.

Re: V6 ignition problems

Posted: Wed Dec 17, 2008 4:14 pm
by mjb
jasper5 wrote:Clean out the throttle body, as before, with carb cleaner
The throttle body's clean

[/quote]and clean out the exhaust gas recirculating valve, EGR valve,this causes surging, misfires, and bad starting when warm, also, intermittant cutting out when it gets clogged up.[/quote]

There's no EGR on the V6 as far as I'm aware. The ES9J4 at least...
The best thing to do with plug leads like those on the V6 is to wrap insulation tape all the way down the lead from where they enter the plug hole.
The leads don't enter the plug holes, there's only 3 leads which go between the coil pack and the 'fake' coil pack on the other side