V6 Engine Problem

V6 Engine Problem

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Discussion

ukflyboy

Original Poster:

246 posts

115 months

Tuesday 14th April 2015
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Hi folks,

As some of you may have seen, I joined the S ranks this weekend, picking up a PHer's S3 from Plymouth and having a beautiful smooth drive home to Oxfordshire. So tonight I go out to enjoy the sun and take it for it's first post-pickup run however all is not well... It starts ok but the engine completely cuts out whenever the revs hit 2500! The previous owner had bypassed the ISCV as it tended to settle on about 2000 rpm but with or without that plugged in the engine completely dies at the 2500 rpm mark.

Anyone able to offer any help? Hope it is something relatively easy to fix?!

mep12345

2,061 posts

200 months

Tuesday 14th April 2015
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Pete, you have mail. I can honestly say it has never done this before. A few suggestions to check on email though based on previous posts for similar problems

Mark

v8s4me

7,234 posts

218 months

Tuesday 14th April 2015
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Our 'S's don't like being sold on so she's just playing you up so you so you don't take her for granted. We've all been there. Once it's sorted just take her out for a good thrash and let her know who's g]the new boss. You did remember to put some more petrol in after the run home didn't you? Now how would I know to think of something like that? laughlaugh

ukflyboy

Original Poster:

246 posts

115 months

Tuesday 14th April 2015
quotequote all
Haha, yes, definitely filled it up after my run and definitely with petrol and not diesel! I've seen somewhere else that it may be worth disconnecting the battery for a bit and seeing if that resets things. Worth a shot?

NiceCupOfTea

25,280 posts

250 months

Tuesday 14th April 2015
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My clutch pedal went to the floor the day after I got it home! laugh How I laughed irked

TVRees

1,080 posts

111 months

Tuesday 14th April 2015
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On my first "big day out with the new S", after 30km, the petrol pump said goodbye for ever and stopped pumping.
Teething troubles, hopefully. Fixed it myself, changed the pump, quite easy really.
Hope you get yours back up and running smoothly asap.

mep12345

2,061 posts

200 months

Wednesday 15th April 2015
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Have had a bit more of a think overnight Pete. If it is cutting out completely at 2500rpm then rather than fuel as I suggested yesterday it would point me to electrical side. I'd check each of the connections in the wiring loom such as large plug in drivers side V, the earths, coil connectors, the small gauge Earth on the throttle linkage etc. if it is just not revving beyond 2500 then d look down the fuel route first. I am sure some others will be along soon to help rather than sympathise.

As I said in the email, this isn't something I've seen before and it seems strange that it would start ok but cut out at 2500. The ISCV has no effect when throttle open so it being bypassed is a red herring. Swap for the spare throttle pot would be another thing I'd do though as quick and easy and rules out a throttle position issue in the electronic control side

Hope this helps

Mark

RayTVR

1,040 posts

142 months

Wednesday 15th April 2015
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Throttle pot would be a good suggestion.

If it turns out that this isn't something easy or obvious, there are a couple of fault code readers among the S community which could help. Due to the age of the ECU as far as I know it needs to be the right Ford tester, rather than a modern code reader. Shout if you need to borrow one.

ukflyboy

Original Poster:

246 posts

115 months

Wednesday 15th April 2015
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Thanks for the help so far folks, keep it coming I'm not the worlds most mechanical person so it is all very much appreciated! I have a good fault code reader among all the bits and pieces that Mark gave me so will have to spend the weekend figuring out how to use it and trying to suss this showstopper out. I kinda want it to be rubbish weather now, just so I don't feel like I'm missing out!

The irony is that the 61 plate day runner I bought the week before is also currently crippled so I'm reliant on my 15 year old 306 that I was planning on selling! Looks like I best keep hold of it a few weeks yet...

v8s4me

7,234 posts

218 months

Wednesday 15th April 2015
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IIRC from other posts on this sort of problem it might be traced to a loose wire somewhere around the distributor, a dodgy earth or something to do with the wiring to the speedo or tacho (can't remember which) but it is connected to the distributor and a faulty connection was causing the misfire. Wouldn't do any harm to check the fuel filter while you're at it but that's unlikely if it cuts out completely at a specific rpm. A fuel problem would be more like misfiring, hesitation and then a cut out and be linked to throttle opening rather an exact rpm. These things are usually something simple but just a bugger to track down. Good luck.

Kitchski

6,514 posts

230 months

Wednesday 15th April 2015
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ukflyboy said:
Thanks for the help so far folks, keep it coming I'm not the worlds most mechanical person so it is all very much appreciated! I have a good fault code reader among all the bits and pieces that Mark gave me so will have to spend the weekend figuring out how to use it and trying to suss this showstopper out. I kinda want it to be rubbish weather now, just so I don't feel like I'm missing out!

The irony is that the 61 plate day runner I bought the week before is also currently crippled so I'm reliant on my 15 year old 306 that I was planning on selling! Looks like I best keep hold of it a few weeks yet...
306 diesels will still be going after the nuclear fallout. The rear axles will be totally shagged, but they'll keep on truckin'!

phillpot

17,105 posts

182 months

Wednesday 15th April 2015
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v8s4me said:
These things are usually something simple but just a bugger to track down. Good luck.
More than likely something simple, a loose multi-plug or a hose off/split allowing engine to suck air from where it shouldn't.



Failing that, cancel the cheque and send "the boys" round to sort out the dodgey seller wink

Le TVR

3,092 posts

250 months

Wednesday 15th April 2015
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I've seen something similar. Turned out to be the distributor rotor arm.
The rotor arm had some kind of spring loaded part to act as a rev limiter, guess it had gone soft?

Be worth checking if you've got the same type in yours.

DamianS3

1,803 posts

181 months

Wednesday 15th April 2015
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I had the soft Rev limiter thing one of my early RS

Cheers

Damian

ukflyboy

Original Poster:

246 posts

115 months

Wednesday 15th April 2015
quotequote all
Ok, thanks folks, I'll have a play around with the distributor and see if that sorts things, might not get a chance to do so properly until the weekend though.

By way of clarfication, it seems to die at exactly 2500 rpm every time and relatively quickly runs down to a stop without really a chance to catch and fire again. It may sound a tiny bit rough running, but I've only ever heard it running twice, so don't have a great frame of reference! It is almost as though it just loses ignition at 2500 rpm so the courses of action above sound like a great start point.


Edited by ukflyboy on Wednesday 15th April 13:51

mk1fan

10,507 posts

224 months

Wednesday 15th April 2015
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Electrical fault? You need a hammer. I know of a guy who's recently got some free time on his hands that might be willing to help.

DamianS3

1,803 posts

181 months

Wednesday 15th April 2015
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What symptoms does a failed ign amplifier give...

If the revs drop like that it doesn't should like the rotor arm limiter IMHO

Damian S3

mk1fan

10,507 posts

224 months

Wednesday 15th April 2015
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Not sure about a failed module but a broken one [that is damaged by an external incident rather than a deterioration] would cut out at random engine speeds rather than a definative amount.

ukflyboy

Original Poster:

246 posts

115 months

Wednesday 15th April 2015
quotequote all
So while I am studiously reading up all the manuals (and Mark kindly gave me several, including the SH bible) about distributors and fault code readers, here is a link to a video I took of it tonight (please excuse quality, its just from my phone).

https://www.youtube.com/watch?v=XM56rpYGVr4

Now I'll reiterate that I've only ever driven a TVR once but what I notice is that the battery light (or "Ignition Warning Light" according to the manual) stays on until a split second before the engine cuts out (I understand it is normal to stay on quite late in a 2.9i?). Is this maybe a sign that there is a problem in the handover from battery to alternator as in the alternator says "right, I've got things from here" but isn't actually supplying sufficient energy for the ignitors so it just cuts out? The battery light comes straight back on afterwards but the engine cuts so quickly that it can't take over and spark things up again...

Edited by ukflyboy on Wednesday 15th April 22:06

mep12345

2,061 posts

200 months

Wednesday 15th April 2015
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Pete,

I assume you've repeated that several times? If so I wonder whether the alternator has failed? Try putting a dvm across the positive to negative and see if you are getting any output. If it is that at least it'll be an easy fix. Others with more electrical expertise will be along soon to comment.

All I can say is this is not something that the car has ever done before, but it must be to do with the change over to alternator from battery given the timing of that cut out