Running on 2 cylinders

JimmyG · Post by **JimmyG** » Wed May 13, 2009 11:02 pm

Hi Guys,

I'm looking for a bit of advice on my 1963 Super Dexta. I completely overhauled the engine last year including new pistons, liners, crank reground, new head, injectors and pump overhauled.......etc etc. She was running like a clock. I'll admit I havent really been using her much, but I would take her out now and again for a spin.

The last time I had her out, she just went off a cylinder....no warning whatsoever. I figured it might be something to do with the injectors, so I pulled them out and took them to the repair shop. After testing them there were 2 stuck while the third was ok.

I thought I'd found the solution to my problem...but alas no!

She's running worse than ever. She will start eventually, but is running very rough. there is lots of black smoke coming out of the exhaust. There is a downswept exhaust on her and the floor is black with soot under the back axle where it comes out.

Does anyone have any idea where to check next?

Is it a fuel problem..... compression problem..... timing problem???

I'm at a loss! I'm hoping some of you guys might be able to help.

JimmyG

roromac · Post by **roromac** » Wed May 13, 2009 11:51 pm

Welcome to the best Fordson BB

Black smoke, as I'm sure you know is unburnt diesel and to suddenly run rough sounds like injector pump. That would be the worst case scenario but as it was overhauled and presumably not by you personally, it could be checked under warranty. It's probably something simple like the cold start extra fuel button.
I have known timing chains slip one cog but you've just done an overhaul so that seems unlikely.
Any other symptoms that might indicate head gasket breach for example?
Rob

roromac · Post by **roromac** » Wed May 13, 2009 11:54 pm

Of course it could be that the rings have shattered on that one cylinder - new though they may be - a compression test would be easier than the injector pump.Equally a dropped valve through ncorrct fitting of collets is possible but there'd be other symptoms.
Rob

Post by **Brian** » Thu May 14, 2009 7:39 am

No timing chains on a Dexta!

Black smoke sounds like air or diesel problems. One cylinder only sounds like injector or injection pump.

I would not think you have a ring problem unless you did not have the engine bored after fitting new liners.

Think I would be looking at the pump.

Please do not run your new tractor engine just on light work or take it out for a spin! That will ruin it very quickly. Put it into the hardest work you can or get your local garage to run it on a dynamometer for a long period. This will bed in the rings and give you an engine that will be powerful and lasting.

JimmyG · Post by **JimmyG** » Thu May 14, 2009 8:30 am

Thanks for the help guys.

When I stripped the engine down originally I found 4 broken piston rings in total, and she was still running better than she is now!! So I'm hoping it's not the rings. The liners were bored out to size by the machine shop and as I said to begin with she was running very well indeed.

I was thinking it may be the injector pump. I just wanted to hear what you guys thought before ruining my new paintwork!

I'll get it off at the weekend and send it off to the machine shop.

I'll let you know how i get on.

Regards,

JimmyG

roromac · Post by **roromac** » Thu May 14, 2009 8:50 am

Good point Brian but it was early in the morning. Citroens have timing chains, Dextas do not.
Brian frequently makes the point that hard work is good for the engine - and it smells good too.
Rob

Dandy Dave · Post by **Dandy Dave** » Fri May 15, 2009 12:37 pm

Sounds like you may have a restricted air way. Did you flush out the air oil bath air filter when you replaced the reconditioned engine? Also, re check the valve settings and be sure you do not have a broken valve spring. It could be a broken plunger return spring in the injection pump, something better done at a pump shop. Good luck, Dandy Dave!