cambelt wants to come off

[stagg65]

Hi all my garage still have my camper.
The problem is they cant get the new cam belt to sit properly its rubbing on one side.
My engine is an AEF 1.9 diesel from a caddy but the diesel pump is still from the 1.6 original lump.
They said to me that there is end float on the oil pump crank ( pulley wheel bottom right with out teeth) but dont know how much travel there should be on it.
Having said that they think the diesel pump is out of kilter which could be throwing the belt out.
Should i just have them fit another diesel pump or is there something we are missing.
Much help needed here or i might just change the whole engine.

[ewenmaclean]

Hello,

I'm not sure about the pump I'm afraid but there are a few considerations - the crank pulley and cam and pump pulley should all be in a plane - also in my experience it's best to centre the belt on the crank pulley as then the harmonic stabiliser doesn't fowl the travel of the belt. The non-toothed pulley you are talking about is the intermediate shaft - there should be pretty much no play in this as far as I know - I would consider looking at the intermediate shaft bearings. If they are no good they can also cause you to loose oil pressure as it's actually a drive for the vacuum pump which in turn drives the oil pump - if it's wobbly these teeth can grind. If you take the vacuum pump out you can see the teeth clearly - see if there is also any wobble on the intermediate shaft there - it sounds a bit like you might need the sump off and to replace the bearings, but that's just a guess.

Hope you sort the problem out - someone more knowledgeable about the 1.6 pump will no doubt have something helpful to say

Ewen

[stagg65]

Hello,

I'm not sure about the pump I'm afraid but there are a few considerations - the crank pulley and cam and pump pulley should all be in a plane - also in my experience it's best to centre the belt on the crank pulley as then the harmonic stabiliser doesn't fowl the travel of the belt. The non-toothed pulley you are talking about is the intermediate shaft - there should be pretty much no play in this as far as I know - I would consider looking at the intermediate shaft bearings. If they are no good they can also cause you to loose oil pressure as it's actually a drive for the vacuum pump which in turn drives the oil pump - if it's wobbly these teeth can grind. If you take the vacuum pump out you can see the teeth clearly - see if there is also any wobble on the intermediate shaft there - it sounds a bit like you might need the sump off and to replace the bearings, but that's just a guess.

Hope you sort the problem out - someone more knowledgeable about the 1.6 pump will no doubt have something helpful to say

Ewen

cheers for your help.

[dave friday]

The bracket that sits under under the injection pump could be out of position causing the problem,the end float on the intermediate shouldnt cause the belt to run off course.
Best of luck.

[colinthefox]

Some things to look for.

The cam belt may have been too tight at some, wearing the injection pump bearing. Take the belt off, then you can check for wobble on the pulley and input shaft.

The AEF mounting plate for the lucas pump is different to the one for the 1.6CS pump. Which one are you using?

If the AEF bracket is used, then the rear (front of vehicle!) mounting for the pump may not be accurately positioned for the CS pump, or may not be used at all, and may be pulling the pump out of line. But the bracket is cast, and very stiff, so I wouldn't think it could have deflected much. The mounting plate is thicker, so the pulley may not line up with the one on the crank.

If the CS mounting plate is used, it is sheet steel, and has more potential to be deflected by poor fitting of the plate or pump, or incorrect injection pipes.

I wouldn't think that a reasonable amount of end float in the intermediate shaft would make much difference.

Could you post up a few photos, so we can have a look.

Has the 1.6 pump fuelling been increased to suit the 1.9 engine? If not you won't get any more power than the old 1.6.

[colinthefox]

Right then.......

I've got my spare unmodified AEF and CS engines sitting side by side in the garage, so I took what measurements as I could without stripping them down.

The AEF engine uses a 22mm wide cambelt, and runs smack in the middle of a 26mm wide intermediate shaft pulley. The cam belt occupies a position between 14 and 36mm from the cast end face of the engine.

The CS engine uses a 25mm wide cambelt, and runs in the middle of a 29mm wide intermediate shaft pulley. The cam belt occupies a position between 13 and 38mm from the cast end face of the engine.

So if you are using the wider CS type cambelt on the AEF engine, it will run off centre of the intermediate shaft pulley. The slight dome of the pulley will pull the belt out of line, due to the tendancy of a flat belt to climb to the crown of the pulley. Either that or it may be unstable and waggle around. Another effect of this force would be to push the intermediate shaft one way or the other (out of the engine I think), which might contribute to wear leading to end float. I suppose the crankshaft sprocket might be a different width too, but I couldn't get at that to measure it.

It seems likely to me that you will need to use the AEF cambelt and tensioner, as it is the tensioner which keeps the belt running in the correct line, which MUST be in the middle of the intermediate shaft pulley.

I worked through all of these issues when doing my conversion, and quickly came to the conclusion that I would have to use the AEF setup complete, or I was going to get problems of this sort. Another thing that interests me is how whoever converted your engine managed to get the water pump to fit, as the mounting bosses on the engine block are different from the CS, but that's a different subject.

Hope this helps.

Colin

[syncroandy]

Er.. I'm not really following all this but it might be worth mentioning the 1.6 and 1.9 belts aren't interchangeable. The 1.9 has a couple more teeth I think.

[colinthefox]

Thanks Synchroandy for pointing that out. You are quite right. How silly of me.

But the CS injection pump, bracket, water pump etc aren't designed to be interchangeable either, and a lot of people manage to get them to fit, somehow. In fact the whole engine is not designed to be interchangeable but that's what we are here for!

Even just the right belt with the wrong tensioner could be the problem perhaps?

[colinthefox]

Or, even just a worn tensioner. We should consider the simple things first I suppose.