Rough Running and Dodgy Speedo

[JSimons]

Hi all,

So yesterday was the pickup's MOT day, and all i can say is, i really don't think the old girl wanted one! Haha.

Got her out the garage, and shortly after taking her out she started spluttering under acceleration. i tried the choke as i suspected fuel starvation but this didn't seem to do much. But the car seems to accelerate okay if you do it very gently, and overexercise of the right foot brings about the issue.

The speedo then decided to play up, was working fine but then would occasionally swing all the way round the gauge, and eventually it gave up the ghost, going all the way round with the slightest movement of the car. The cable is fine so it must be the speedo head itself but i wouldn't know what to look for or whether they are fixable.

One of the sidelights then stopped working, this was one of those days.

Anyway, managed to fix the light and obviously the rough running wasn't an issue for the MOT as she did pass. A trooper as always!

Well tonight i took the float bowl lid off and inspected the float which was fine and i couldn't see any crud in the chamber itself. I have had an issue in the past which meant the carb needed to come off and be cleaned thoroughly as again the lines became blocked. I was running with low petrol in the tank so i was wondering whether it sucked some crud through.

I then took her round the block a number of times to see if it would clear through but can't notice an improvement, i have checked the damper pot oil level which is also fine. The strange thing is the speedo now works at over 20mph. It spins round and goes crazy up to there but then seems to work fine.

The running also doesn't seem to be inhibited when the car is in neutral so i was pondering other issues such as the condenser?

If anyone could shed some much needed light on the situation it would be much appreciated.

Regards

Joe

[bmcecosse]

Can only suggest running through all the normal ignition checks/replacements, but note it won't be the coil........ And you can test the speedo by removing it - and running it up with a reverse running electric drill. If it's smooth with the drill - the fault is in the cable or the gearbox drive unit.

[katy]

The "spluttering under acceleration" sounds to me like a spark plug problem. Even if they look good, try a new set.
The erratic speedometer sounds to me like the cable and the inside of the cable housing need to be cleaned and re-lubricated.

[JSimons]

Thanks for the replies.

Will check the plugs and ignition in general and report back

Will also look at the speedo cable, it was new around 2 months ago so thats why i didn't think of it. Also when i took it out of the back of the speedo, the speedo remained at around 20mph with the needle 'sticking.'

Regards

Joe

[Dominic]

If you have a problem with the speedo, I can recommend this chap.

http://www.jdo1.com

Dom

[C6Dave]

If you have a problem with the speedo, I can recommend this chap.

http://www.jdo1.com

Dom

Much cheaper than 'Speedy Cables' for a speedo overhaul and nice to deal with (just had my glovebox lid clock overhauled by him)

[JSimons]

Thanks for the replies

Turns out the rough running was due to a failed spark plug. Fitted a new set and away she went. Nice and simple.

The speedo oddly seems to be behaving most of the time, well is relatively useable.

Regards

Joe

[bmcecosse]

In which case the problem is likely to be in the drive/cable.