2.5 n/a lumpy idle and white smoke missfire?

Well as an update I got it to stop smoking, tried everything else so adjusted the injection pump away from the engine about 3mm, don't know if thats advanced or retarded it but it seems to have done the trick, idles now with only minimal smoke and revs fairly cleanly (did adjust the fuel on the pump as well).
Given me renewed confidence that I might actually be able to take it on the road now and only annoy cyclists.

Be aware that if you turn the pump the other way it will run like a sewing machine but it will also run hot in the chambers, so turn it back until it smokes then just slightly eliminate the smoke, dont be tempted to turn it any more, all you want to do is eliminate smoke, making it run smoother could be something else. Also, its a good idea to recheck the timing with the correct pins.

As an update got it running fine today though started to rev high when left at idle and slow to drop revs when throttle lifted. I have had this problem with the 88" when I ran it dry due to a faulty fuel gauge and just before running out the revs would raise and lower by themselves.
Got plenty of fuel this time but there is a bit of air in the fuel filter(glass bottom type) that I can see. Is it likely to be a symptom of air in the filter of is it a case of adjusting the idle stop bolt and throttle stop to get the revs to drop quicker.........google can be your friend and it can also lead you up a cul-de-sac, any ideas welcome.
Cheers
RJ

Rising revs like that usually indicates a very lean mixture, which would happen if the carb is running low on fuel until the next gulp arrives to refill the float chamber. Does seem like you have a fuel starvation issue - don't know whether it would be just due to a bubble or something else resulting in inconsistent flow. Not sure it's as simple as idle/throttle stop adjustment.

I would agree but its a 2.5n/a diesel lol.

Rodeo Joe said:

I would agree but its a 2.5n/a diesel lol.

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It is the same kind of effect though which is why I thought maybe an air leak somewhere.

Ah, OK. Please disregard! I only saw the topic after I'd hit 'Reply'!

If its air it'll just stop. Try putting your pump back to its start position and try again without adjusting fuel.

Its worth the hassle to hit the engines sweet spot as it will run for ever and very well.

Bobsticle said:

If its air it'll just stop. Try putting your pump back to its start position and try again without adjusting fuel.

Its worth the hassle to hit the engines sweet spot as it will run for ever and very well.

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I put a jerry can of fuel in yesterday and it sat and idled for 20 mins without any problems. Have noticed its getting harder to start and as theres no smoke to start with I think the fuel is draining back to the tank overnight so has to be pulled back up through the system.
Was thinking there might be a pinhole in the old fuel pickup in the tank so when it gets low it sucks in a bit of air as well.
Going to have a tinker later so I'll see how it starts(or not)today once I've charged the battery up again.
As far as the sweet spot goes it does actually run very well, a bit of smoke but I'd be worried if it didn't. Kicks out a bit of black when under some load so reckon its as good as it gets for what it is.

I had a Series 3 diesel with a 200Di fitted. It smoked like a burning supertanker. Turned out to be two problems :
1. Someone had changed a section of fuel pipe using a push-fit union. These are fine under pressure, but with the vacuum created by the fuel pump, allowed a stream of air bubbles into the fuel.
2. The top of the fuel tank pick-up pipe had corroded, letting more air bubbles into the fuel.
Diesels do NOT like running on froth!
Fixed these, all was sweet. Good luck.