Choking power.

I have a 3.5 ltr Rover V8 on SU carbs fitted to my series 2A. It runs really nicely, but I can only get any power (for overtaking for example) by pulling the choke out. When it's out, there is loads of power, when in, it feels as though its fighting to accelerate.
I've got new plugs (with correct gap), new leads, timing checked, new coil, and a flow restricter in the fuel tank return line fitted, so there is plenty of fuel available to the carbs.

Can anyone light my way to correcting this please?

If you're having to pull the choke out could it be the accelerator cable on the pedal being a bit loose or over stretched so its not allowing for full throttle

I'll have a look tomorrow, that could be the problem as the cable is new too and could need adjusting, it's the overall response of the engine that seems to be lacking with the choke in. Thanks for the reply.

No worries mate, hope that works

I had a look at the accelerator cable, it looked ok, the slightest of pedal movement did have an input to the carb linkage. I am thinking of taking it to RPI Engineering for a look, although they do charge a bit for their time. Any other ideas would be most welcome.:blabla:

moofletch said:

I had a look at the accelerator cable, it looked ok, the slightest of pedal movement did have an input to the carb linkage. I am thinking of taking it to RPI Engineering for a look, although they do charge a bit for their time. Any other ideas would be most welcome.:blabla:

Click to expand...

Petrols aren't really my thing but it sounds like your running a too a weak mix. Have you had the plugs out to look at their colour?

Not since I have replaced them. I'll have a look over the weekend.

Make sure there are no air leaks in the seals as well. When an engine runs at norm temp, when you pull choke out it should "hunt" as it gasps for air, not give more power

On the su's I can't remember if their is another jet that when the accelerator is floored it gives it a boost... Or I maybe thinking of something else ???

Take a couple of plugs out, colour should be tan colour, if it's a bit dark brown then that's ok, if they're pale / White then mixture is too weak

moofletch said:

I had a look at the accelerator cable, it looked ok, the slightest of pedal movement did have an input to the carb linkage. I am thinking of taking it to RPI Engineering for a look, although they do charge a bit for their time. Any other ideas would be most welcome.:blabla:

Click to expand...

Sounds like a tune up might be in order, or maybe a carb rebuild, or even just re-jetting.

Personally I'd just take it to someone local who knows a bit about old engines, SU's and RV8's aren't rocket science, any half witted mechanic should be able to help you out.

I took it to RPI Engineering the other day, the engine was still set up for the LDV riot van that it came from. They advanced the timing a few degrees, played with the jets a little bit, fitted Magnacore HT Leads and replaced the electronic ignition amp with a hoofing great one attched to the side of the engine bay. It runs like a dream now, Bags of power and sounds fantastic.
I just need to close up the holes in the carb butterflies
(an LDV thing for convoy driving apparently).
Thanks for all of your replys guys.