V8 (RRC) Fault

[McSwerve]

My 90 is unwell.

It was running very rich (but bally fast and 100 miles to a tank), so for the MOT the garage ‘turned it down’.

Now it initially runs OK with the choke out when it’s cold. Then as it warms up and you put the choke in, it hesitates and power dies down at low revs. Then at mid-revs there’s no real power. It never gets to high revs.

Any thoughts?

Or does anyone know a good indie near Bedford.

Cheers

[Range Rover Blues]

Coould be the jets are worn out, they don'tlast forever.  Or the float level is wrong.  Needs a carb specialist really.

[DogVanMan]

Does it get any better when warm if you temporarily pull the choke back out? Sounds lean to me. (I.e. Worn needles caused it to be rich and now they've over done it. OK on tickover but progressively leaner up the rev range.) I know a very good guy with V8's and SU carbs but he's in Derbyshire.

G

[McSwerve]

It does get a bit better pulling the choke back out.

So does it sound like the carbs are now [!Expletive Deleted!], or just needing an overhaul & reset?


(Many thanks for the input chaps)

[DogVanMan]

It does sound like worn needles and jets. They would cause it to run rich, and fail the MOT, so the garage adjusted it leaner to pass the MOT but now it's TOO lean higher up the rev range - until you pull out the choke a bit. Options really are:

1) Horrible bodge: Pull the choke out a bit when it's warm and you want to drive it anywhere above tickover speed.

2) Still a bodge but not quite so horrible - Adjust it back a bit so that it's richer again (You don't have to pass the MOT for another year!).

3) Proper answer: Have the carbs rebuilt and bask in the warm glow of righteousness.

Obviously two of these options are environmentally unsound and the planet will probably fall off it's axis if you choose them. Also bear in mind that rich and lean mixtures aren't good for engines, either of them.

G