Engine miss 'normal' for Griffith??
Engine miss 'normal' for Griffith??
Author
Discussion

tgjr

Original Poster:

750 posts

257 months

Tuesday 7th June 2005
quotequote all
I have recently bought a Griffith which I think is great but noticed on a motorway trip that at a constant 80mph (in Germany!!!) the car occasionally misses and you can feel a definate stutter. On reporting this to the supplying dealer I was informed that this is a common trait on Griffiths and nothing to worry about. This may well be the case but I thought I would check for opinions of other drivers - does your car do this? Mine is fine under acceleration, just at a constant speed, about 3000rpm.

lazyitus

19,931 posts

295 months

Tuesday 7th June 2005
quotequote all
Mine has done this on the odd occassion.

I dont and wouldn't worry about it.

Wildfire

9,948 posts

281 months

Tuesday 7th June 2005
quotequote all
Mine's not done it. Done Manchester to London twice in it.

richb

56,241 posts

313 months

Tuesday 7th June 2005
quotequote all
I wouldn't say a misfire is normal, something obviously needs attention. Rich...

steve-v8s

2,924 posts

277 months

Tuesday 7th June 2005
quotequote all
Missfire as you decribe on mine was one of the nasty GM plug caps, The spring inside was broken. It will run without them but the leads rest on the manifold and get a tad hot.

GreenV8S

31,017 posts

313 months

Tuesday 7th June 2005
quotequote all
It may be a common trait on Griffiths that he looks after, but not for cars that are in good working order.

MisterT

326 posts

255 months

Tuesday 7th June 2005
quotequote all
I bought my Griff back in march, I have a similar problem, at steady speed with light or part throttle there is a surging rather than a misfire (like the throttle potentiometer has spikes on the resistance track). However just this evening I have been on the diagnostic tuner and all checks out OK, have reset throttle pot, idle speed, checked & cleaned stepper. It now idles beautifully and has no problems under load, but still surges on part throttle, it is particularly apparent when driving through villages etc at 30 or 40 and doesnt matter what gear/engine speed it still surges. By the way the car has also had new plugs, leads, amp pack and coil.

Anyone any ideas?

I did wonder if it is just down to the state of tune, my car is an Aug 94 model and completely standard as it left the factory, I gather later engines were 'detuned' slightly to 'improve' their behaviour?

GreenV8S

31,017 posts

313 months

Tuesday 7th June 2005
quotequote all
MisterT said:

Anyone any ideas?

I would have said throttle pot, but you tested that. You could try disconnecting and plugging the vac advance line ? Does sometimes help with low rpm manners, apparently ...

lazyitus

19,931 posts

295 months

Tuesday 7th June 2005
quotequote all
I must add to my above post....

I had a misfire problem (bad misfire, not the odd blip) until recently. New leads, dizzy and rotor arm has solved the bad misfire.

This is probably related.

gingerprince

571 posts

270 months

Wednesday 8th June 2005
quotequote all
MisterT said:
it is particularly apparent when driving through villages etc at 30 or 40 and doesnt matter what gear/engine speed it still surges.


No no no no no, you're mistaken! I think you'll find that's your subconscious blipping the throttle to pose in villages

TGJR

Original Poster:

750 posts

257 months

Wednesday 8th June 2005
quotequote all
Some interesting points! It would appear that I am not alone with this but then after all we are talking TVR!! The fact that the miss is not under load but at steady speed probably suggests electrical rather than fuel. I agree with the replies that point to HT leads as these are a potential weakness under heat and the Griffith engine bay gets very warm. I may be tempted to change these if the problem gets on my nerves. Cheers all!

jimbro1000

1,619 posts

313 months

Wednesday 8th June 2005
quotequote all
MisterT said:
I bought my Griff back in march, I have a similar problem, at steady speed with light or part throttle there is a surging rather than a misfire (like the throttle potentiometer has spikes on the resistance track). However just this evening I have been on the diagnostic tuner and all checks out OK, have reset throttle pot, idle speed, checked & cleaned stepper. It now idles beautifully and has no problems under load, but still surges on part throttle, it is particularly apparent when driving through villages etc at 30 or 40 and doesnt matter what gear/engine speed it still surges. By the way the car has also had new plugs, leads, amp pack and coil.

Anyone any ideas?

I did wonder if it is just down to the state of tune, my car is an Aug 94 model and completely standard as it left the factory, I gather later engines were 'detuned' slightly to 'improve' their behaviour?


Mine did exactly the same and it turned out to be a loose contact on the ECU plug. All sorted now but it took some time to find!

dnb

3,330 posts

271 months

Wednesday 8th June 2005
quotequote all
Little surgings on part throttle can be caused by the lambda sensors as they adjust the AFR... My old Impreza used to do this sometimes.

ben4grif

12 posts

283 months

Wednesday 8th June 2005
quotequote all
Mine did stutter at idle, every minute or so it missed a beat/backfired. Turned out that one pre-cat was out (by a pevious owner who obviously din't now what the **** he was doing), the other one still in, so the mixture was adjusted wrongly because of different readings for the lamda sensors. Did not occur under load/higher revs.
But ,indeed much higher chance of HT leads/plugs being out of order.

IPAddis

2,524 posts

313 months

Friday 10th June 2005
quotequote all
Mine started doing this after it's recent (and otherwise excellent) service at Peninsula. As a result, it looks to be some electrical tweak rather than component failure.

On my car, it's at a steady cruise, you just get a sudden blip in the power as if you've suddenly let off the gas for a split second. Does it 4 or 5 times in the space of a minute and then stops for an hour or so.

In fact I don't remember it doing it for a while so maybe it's just the ECU recalibrating the fuelling after being disconnected.

My workaround is to ensure that I'm always accelerating!

Ian A.

MisterT

326 posts

255 months

Friday 10th June 2005
quotequote all
Thanks for suggestions, tried most of them with no success so far. Must have it fixed before Thursday (travelling to Le Mans) so I have now booked a diagnostic session with V8 Developments on Monday morning, hopefully this will reveal the problem, so will let you know.