My car will now not rev! I stripped down the engine a couple of weeks ago I suppose, to helicoil a spark plug as well as replace the push rod seals. The engine ran fine after doing this (but still consumes its bloody oil!) but the other day I approached my brother’s house and the car, by itself decided it didn’t want to idle anymore and cut out just before tick over. When driving it home however it seemed ok I just had to keep the revs up in traffic. However when I got home, it seemed to rev and run lumpy. So we had a look at the carb settings and blew out the idle jet etc. that seemed to make it worse so we to the lid off blew all the jets threw and set the float height and eventually, my dad got the car to work as before. So he took it out for a spin and it ran fine then subsequently went out in it and it started to misfire, then judder before coming to a halt, cutting out. He left it for a bit, got it going and limped it home.


Later on today we had another look at it. Again we managed to fettle the carb and it started, ran and revved fine so we took it out and after working perfectly for a bit, starting exacting the same symptoms, it spitted and farted, juddered about and rolled to a halt but this time, it didn't stall but it would not rev. Because we were sat in a national speed, on a corner, I tried, after a few minutes, to crawl along on idle. It was then that it decided that actually it would like to accelerate after all, so it did! We then stopped had a pint and came back when it decided to be a complete animal.


It started juddering about every ½ mile but gradually got closer and closer as we neared home to about 200 yards. My brother fiddled the carb to keep it going until that no longer worker. In the end I had to crawl up the high street, the choke as my accelerator because the throttle did sod all except slow it down.


Don’t know whether this is relevant or not. I did about 2100 miles around Europe over the summer. It’s fairly low on petrol, although it started playing up on ¼ of a tank and that was ESSO petrol. I redid the timing and adjusted the tappets a couple of weeks ago. It seemed to get worse as it got hotter. It has a 123 ignition and a Harley coil. Any help will be greatly received because it's now undrivable! :confused:

I would change the points capacitor and check that the points are clean. Check also that the cam which operates the points doesn't have excessive play in it such that at higher engine revs the points gap changes. I assume that the fuel line / pump are delivering sufficient volumes of fuel.
BobH

OOps, I didn't read the bit about the electronic ignition - how quickly could you disable the 1-2-3 and put old points etc back to prove that its not ignition.?

Had similar problems, changing various things, coil, plugs, leads, 123, etc. mostly whatever was changed fixed it for a bit, few miles/days, but it'd come back. Eventually it turned out to be coil (mostly - the 123 was causing poor, 1 cylinder, starting and poor tickover) I had 3 duff coils in a row, with different problems; one died when it was hot, one was very poor cold(?) & one was just classic dying coil not starting hot. All black ones, Citroen and 2 of whatever ECAS provided - none were new I hasten to point out! Took about 18 months to sort because my usual swap a componant with another and see if it cures it was defeated by all my coils working but badly.

Check your plug leads as well......

Thanks for the replies everyone! bobh, I'm afraid that, that engine didn't come with any form of ignition when I bought it, it was a project and I only have the 123. As I say it's got the yellow Harley coil and it idles fine.

I had a look at the fuel pump. I took the pipe going to the carb off and turned the car over. I'm not sure what constitutes a good jet of fuel, but it gave a spurt of fuel that going horizontally would be no more than a foot. Weirdly though, as soon as I pushed the accelerator, the fuel output decreased to almost a trickle. I don't want to state the obvious or anything like that, but surely the fuel output would increase the more accelerator applied?

This would make sense in that it drove perfectly for a bit, while the carb was full of fuel, then coughed and spluttered and then wouldn't accelerate, because the carb was near empty, but still idled. Then, after a while, when the carb had filled up again, it drove for a bit before repeating.

Strangely enough, the engine-driven fuel pumps used on A series Citroens are less effective at high rpm, most probably due to the effects of inertia on movement of the fuel and the one-way valve diaphragms in the pump.

However, if the pump is working correctly and there are no blockages or air leaks in the line between the tank and the pump, the output should not decrease to a trickle at higher rpm.

Thanks for that Ken. So would I be right in saying that the next course of action would be to check the fuel lines for any splits etc. that could allow air in before the pump and if the lines appear fine, replace the pump?

How about the fuel pump? Even if it's new, that's not a guarantee that it's working correctly, unfortunately...