3 things wrong - Related?

[dlkbs1]

Hi all,

I have a 1993 4.3L Chim.

For a while now it has stalled occasionally on dipping the clutch approaching junctions etc, usually the faster the de-accelleration the more likely it does it. Noticed on other threads this seems fairly common and seems there are a number of possible solutions. Anyway had a 6k service a week or two ago and stepper motor was cleaned and reset - no difference though.

On the way back from Fairford airshow at the weekend cruising in 5th it died slightly for a couple of tenths of second on about 8 or 9 separate occasions (only in 5th at constant revs), just as if I had lifted off the accelerator, no bangs or pops, no ignition lights etc. had two different types of super unleaded in the tank during the drive back as well. The other thing was the speedo started playing up as well, sticking at 50mph, and then moving again but not reading the correct speed at times.

Could all this be down to the speed sensor, incidentally is it obvious to find on the old SD1 gearbox - seems the Bible only covers the diff mounted version!

Any advice appreciated.

p.s. was stuck in a stationary stop start queue for about 3 hours trying to get in to the airshow (won't be doing that again), She never missed a beat, lots of other more modern mass produced cars were overheating and requiring attention.

[Mike Hawthorn]

Have the HT leads been changed lately? I had much the same problems. I found the Distributor vac advance unit broken and the Stepper Motor was also buggered. Changed the Vac unit and to be honest it made no difference but I needed to discount it. Stepper Motor helped a little but frankly new leads and caps done the job. It's gone from being rather unpredictable to perfect. The main problem is that if you get a plug miss a beat the Lamdor sencer sniffs petrol and adjusts accordingly and mucks everything up cos the plug fires the next time round and now it's to weak. It seems to do this constant re-adjusting for a while then just cuts out. (almost like it gets pi%$ed off)It'll start up no problem and it's like it's all ok again. I also found that the metal covers on some of the caps get corrosion under them and this can cause a misfire. I took all the metal covers off mine and it fixed the problem. Fitted new caps and leads a couple of weeks later. Hope this may be of some help.

[dlkbs1]

Thanks Mike,

I have had the car for a year and not changed them, but no idea how long they have been on, they do look in decent condition. Plugs had just been changed at the service the other week, would have hoped they would have commented if the plug covers were on the way out as the guy who did the service knows these inside out.

[spend]

Early chim has speedo speed sensor on front of diff and separate sensor for ecu on gearbox.

Check for air leaks after the AFM. The legendary ignition amp does lots of strange intermittent things when it is on the way out.

Dave

[chimalsu]

im sure the speed seender is linked to the ecu so if thats playing up could be sending wrong info and incorrectly adjusting the feulling

[davetherave1970]

dlkbs1 said:

cruising in 5th it died slightly for a couple of tenths of second on about 8 or 9 separate occasions (only in 5th at constant revs), just as if I had lifted off the accelerator, no bangs or pops, no ignition lights etc.

Mine did this and it turned out to be a faulty air flow meter.
I got a recon one from http://www.douglasvalley.co.uk/