It doesn't do this all the time but sometimes when I take the Sprint for a run it seems to run a bit jerky. It does it when you are sat idling at a junction (you can feel the car shake), when you are doing a steady speed for example, 30mph, 50mph or 60mph. When you start to accelerate it seems fine. Like today I took it for a spin. It seemed fine to start with but after about five minites to started to feel really jerky again but when I got back home I was sat outside the house waiting for my dad to move his car out the Sprint was idling fine again? Its been like this ever since I filled up at a petrol station back in June on my way to Mallory Park this year. I normally fill up with Shell but on this occasion I used a Jet station as I need some fuel. I was wondering if it was a different type of fuel that I used that was causing this but I have filled up with Shell and Shell V-power since then but it still does the same thing. I last took the Sprint for a run for about 40 minites about four weeks ago and it ran fine. My thoughts are that maybe the idle jets maybe slightly blocked and maybe need to be cleaned out? Any help would be appreciated
It sounds like a blocked idle jet mark, i'v have this happen a few times this year when i changed the petrol pipe. when the car is warmed up remove a spark plug lead one at a time till you find the one that doesn't cause a change in the rough engine idle. This is the cylinder that has the blocked idle jet as no petrol is getting through. Just remove the air filter and take out the idle jet associated with that cylinder and you should be able to see if its blocked
Thanks for the replys guys I had the carbs setup back in July along with a compression and ignition check this year and they are fine so it could be a slightly blocked idle jet. The fuel filter is just over a year old but it would be worth replacing this as well
I would recommend using a carb cleaner it helps when cleaning the jets, I have used an air compressor to clean them before and the dam thing shot out my hand and took 3/4 hr to find again lol. It also pays to order some new spare ones , they are quite cheap from southern carboretters.
This could be why it runs a bit off now and again. The filter is full of crud and could of possibly been restricting fuel. Fuel is obviously getting through but maybe not enough. The filter is just before the nearside carb so it maybe feeding that one just enough but by the time the fuel runs to the offside carb there might not be that much fuel coming through.