"Stuttering" at the cruise

"Stuttering" at the cruise

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Discussion

cinman

Original Poster:

182 posts

260 months

Tuesday 22nd April 2003
quotequote all
I have a question which I hope someone can assist me with. I have a Cerbera 4.2 '97 and find that on the cruise, not accelerating nor decelerating - just cruising (irrelative of gear) that it "stutters". This is not so major so's to throw me forwards and back in my seat, but certainly enough to feel. Is this normal? If not, what might it be? If it IS normal, then is there any way to "smooth" it out a bit?

williamball

4,406 posts

289 months

Tuesday 22nd April 2003
quotequote all
They all do that sir...to a certain extent.

Check the magnetic crank pickup [right side of clutch housing] hasn't picked up any metal filings as that can put the timing out.

Make sure all the other sensors haven't returned fault codes and make sure the throttle pots are set up etc.

Former is a DIY task, the latter is probably not.

WB

cinman

Original Poster:

182 posts

260 months

Tuesday 22nd April 2003
quotequote all
I'm due to get Andy at APM to take a butcher's at it on Saturday coming, so should be interesting to find out what he's got to say about it.

Thanks Will, will let you know what it is.

S1NRR

144 posts

260 months

Tuesday 22nd April 2003
quotequote all
Hi, Just saw this post....I have had exactly the same problem with a Brand new Tuscan S you are going along at about 80 and you feel this hestitation very slight more anoying than anthing, mines set up right and everything same answer from dealer its one of thosethings.....

Danny

beej

258 posts

275 months

Tuesday 22nd April 2003
quotequote all
£50 says its one or both throttle pots.. that is, I think they cost about £50! Go see Andy, you need to hook the ECU up to the pc.

cinman

Original Poster:

182 posts

260 months

Tuesday 22nd April 2003
quotequote all
Andy seems to know his stuff, and I look forward to the outcome of this weekend's drive over to his place in Liphook.

When accelerating, still goes like the clappers, a real beauty ... just cruising - and like you said earlier - a little annoying more than anything else. If it turns out to be fine according to computer, etc., then that's fine.

anonymous-user

61 months

Tuesday 22nd April 2003
quotequote all
Yep, that'll be throttle pots alright..shouldn't take long to correct and Andys a top man.

gazzab

21,232 posts

289 months

Tuesday 22nd April 2003
quotequote all
Glad that more people are shouting about Andys ability etc.. Think he was worrying that I was going on about him a little too much and that my intentions might have been a little bit biblical !

joospeed

4,473 posts

285 months

Wednesday 23rd April 2003
quotequote all
i've got two mods which cure 99% of throttle pot related faults .. can only claim credit on one of them though, the other (more technical) mod was worked out by a clever / persistent customer no less ..

cinman

Original Poster:

182 posts

260 months

Wednesday 23rd April 2003
quotequote all
What are those then?

vroom

665 posts

291 months

Wednesday 23rd April 2003
quotequote all
Hey Joolz!

I hope you mean 'determined' rather than persistent…

Admittedly, I did persist in hassling you though for the vital clues though!!!

Nick.

joospeed

4,473 posts

285 months

Wednesday 23rd April 2003
quotequote all
.. after all your hard work nick .. you deserve a share of any profits on these jobs .. remind me to speak to my accountant about that!!!

vroom

665 posts

291 months

Wednesday 23rd April 2003
quotequote all
Joolz,

She's still running like a dream...

An added bonus - MPG has improved dramatically. Not being frugal or anything, but MPG was completely dire beforehand.

Which would make sense I suppose... No wonder cats used to smell like rotten eggs before.

gazzab

21,232 posts

289 months

Wednesday 23rd April 2003
quotequote all
So come on guys - spill the beans re these throttle fixes!!?

JAK

121 posts

275 months

Wednesday 23rd April 2003
quotequote all
Mine is due for a Service and the stuttering problem has been with the car for about 1000 miles or so - Happens mainly when car is well warmed up. I had the same problem prior to my last service and required a new throttle pot.

I remember reading about a throttle return spring mod that Jules had come up with. Would this help?

cinman

Original Poster:

182 posts

260 months

Thursday 24th April 2003
quotequote all
So what's the mods then? Can I get them at APM or would I have to do a JooSpeed jobbie? How long, how much, how effective?

joospeed

4,473 posts

285 months

Thursday 24th April 2003
quotequote all
anyone out there can do the mods, I'm not going to claim it's only me that can do it - in fact the mods are relatively simple .. all you need is an in-depth knowledge of MBE ecus, mechanical knowledge of what causes initial throttle pot failure and a sound grasp of electronics. for everyone else, form an orderly queue... requires internal ecu reworking so not a DIY job.

grey42cerbie

415 posts

273 months

Thursday 24th April 2003
quotequote all
Joolz,

Does your mod sort out the general instability or just the reliability issues.

Steve, on his fourth throttle pot
Grey 4.2 Cerbie

vroom

665 posts

291 months

Thursday 24th April 2003
quotequote all
I hope Joolz doesn't mind me adding something here:-

The mod was to improve driveability at part throttle. The hesitance / kangarooing I got at the time I felt was 'in addition' to the slight hesitance you get generally with this engine.

There are also fuelling issues and throttle linkage issues I beleive that contribute here- Joolz also has fixes for the latter.

The results were (and still are) dramatic - town driving / cruising is now a real pleasure.

Nick.

madasahatter

374 posts

274 months

Thursday 24th April 2003
quotequote all
How much for the mods Joolz. These sound very interesting.

Also, was the MPG improvement down to these mods, or was there something actually wrong with your car Vroom?

Steve