Engine troubles

[walzaher]

Hi everyone,

Today I was driving my old bedford and when I came to start her in the evening i noticed it didnt start as quickly as usual, i had to keep the ignition twisted for a few secs for it to start up. Then all was fine. a few hundred m's later while driving the van felt very bumpy, the engine was revving up then down up then down and didnt feel right. Then the engine started turning off everytime i let go of the accelerator to change gears. Then the engine wouldnt start unless I continued to give it gas. I managed to drive home with the choke pulled to medium so that the engine would keep going.

From my research I think this is a problem with the carburetor / spark plugs. Can anyone please advice me what they think it is? and how to go about fixing it.

Thanks veeery much =)

Waseem

[MaTTe]

Check that any rubber plugs that seal off parts of the carby aren't split or missing. If you can hear a hissing when it's running, trace it back and see if you can block the vacuum leak with your finger, if so it should make the van run better despite most likely dropping the revs.
You may well have had the exhaust manifold gasket blow out, causing it to take part of the intake gasket with it (they're both the same gasket obviously) If you're really unlucky it may have blown from the exhaust port into the intake port, which will be screwing with your mixtures on one (or more) cylinder.

You may also find that the points have worn to the point that spark is too far away from optimal. If you're running a 202 which I assume is the case, get a set of feeler gauges and set the points to 14thou. I advise getting a points file and filing the points first, they're quite cheap from a hardware store or auto shop. When setting the points, turn the motor over by hand whilst watching the distributor with the cap and rotor off. Watch the points opening until they open to the peak distance, this is where you need to set the points gap.
Unscrew the points, adjust using a screw driver to spread or more likely close the points with the adjustment slot. The gap will most likely change when you tighten the adjustment screw, so you may need to do it a few times to get it right. You want the 14thou feeler gauge to be tight enough that there is absolutely no slop, yet loose enough that you do not spread the points when sliding the feeler gauge in.
This should give you a dwell of around 36deg if you have such a gauge.

If none of these are issues, change your fuel filter. If this does not sort out your problem you need to look into things like plug wires that are faulty, or pull the top off the carby and ensure there is nothing floating around in there, or any gaskets broken..
Good luck

[Gordon]

Hi Waseem, if MaTTe's checks don't reveal any issues, my suggestion would be that with the van running (you may need a helper to press the accelerator to keep the revs up a bit if she keeps stalling at idle) you disconnect one spark plug lead off its spark plug at a time (take care not to shock yourself). If the engine note changes or the motor stalls or running gets worse then you know that that cylinder was firing OK. Replace that plug cable and do the same process with the next cylinder. If the engine note / idling doesn't change then you can be pretty sure that the problem is isolated to that cylinder. Options could be a faulty plug or spark plug lead. Spark plug leads do break down over time. Another old trick is to run the motor in the dark and watch for arcing on your spark plug leads which would indicate a break down of the insulation on the lead resulting in your spark going to earth and not reaching the spark plug.

I hope its nothing serious.