V8S lumpy running when cold

[barkychoc]

The V8S I've just bought runs very lumpy and stalls now and again until it is warmed up.
Obviously the best plan is always to warm it up first anyway - but this isn't always convenient.
Can you give me some pointers at what to look at - though I don't want to risk any of the setup when its warm as it runs great once warmed up.

Chris

[GreenV8S]

Worth checking the coolant temp sender I suppose, it should be 5kOhm at 0C roughly halving per 20C rise.

[barkychoc]

Gauge works fine - is there a seperate sensor for the injection system ?

A bit more detail;

Car starts first time, idles fine.
Blipping the throttle it stutters like the mixture is weak, and trying to drive it before its warmed up it 'kangaroos' a bit, not severely but enough to look stupid!
Can stall when you come off the gas.

Any help appreciated.

[GreenV8S]

barkychoc said:

Gauge works fine - is there a seperate sensor for the injection system ?

Yes.

[pies]

GreenV8S said:

barkychoc said:

Gauge works fine - is there a seperate sensor for the injection system ?

Yes.

IIRC its at the top front on the nearside bank,there may well be a spare unused next to it as well

[stevetvrs]

Chris,

Remember those wise words?... "With all this fiddling, prodding and adjusting I think I would now decide its time to consult a professional - it could end up costing more if you go and break something or replace a number of perfectly good parts before you get the right one.
Just an observation - its a great feeling to fix something yourself but its also important to admit to yourself when you need some expert help.
Plus of course you're likely to get it fixed quicker - so you can enjoy driving it more!"

Sorry, couldn't resist it

I'm sure one of the V8 boys will be along with some answers shortly. You may find that if you search this forum, along with all of the other V8 engined cars, you'll come up trumps. Welcome to TVR (hands-on) ownership.

Steve

Nice car by the way

[barkychoc]

Thanks Steve - and yes I remember those words !
I'm going to have a quick look, poke, prod etc.
If I can't mend it easily there's a land rover specialist down the road might try them, hopefully they should know the V8 !

Cheers

Chris

[GreenV8S]

Coolant temp sender is connected to pins 25 + 7 on the ECU plug.

Fuel temp sender is connected to pins 25 + 32.

[eng622]

When I had the car it was ok in the winter months and seemed to get worse as the ambient temp rises, so I guess there is a clue there. My guess is that it runs weak for around a minute as it warms up.
Melvyn

[barkychoc]

Thanks Melvyn (eng622) - I'm going to have a look shortly.
Watch this space !

[barkychoc]

Well a great start - went out in the rain to find my multimeter has died, so couldn't measure resistance of any of the sensors.
Anyway had a general check and the vacuum hose to the distributor was in a sorry state - looked fine but when you inspected it more closely it was like a bit of sticky liquorice. The end where it joins the distributor had a bit of a kink in it and I reckon because the hose is so soft & gooey when its getting a bit of vacuum it could be sucking itself flat & the vacuum advance stops working.
Anyway for now I've cut the end off and refitted it, as the end was much worse than the rest.
Took it out for a quick spin stone cold and it was absolutely perfect.
Melvyn (previous owner, eng622 above) did say it was worse at startup in warm weather, and its not that warm today so time will tell whether its this or not.

Chris

[barkychoc]

Well it was reasonably warm this afternoon so took for another spin cold and perfect again, so reckon I've sorted it.

Performance has definately gone up a notch too!