Re - 1.9 Water Cooled Petrol Engine - Rocking on tick over

Post by **nenenaiad** » 14 Nov 2008, 17:17

Hi,

The 1.9 Petrol engine fitted witha a Weber 34DAT carb is proving to be a bit of a pig to get to tick over properly.

Either using info from Weber about carb setup or trying to set the CO to 1.5 +/- 0.5 using a CO meter the result is the same, with a violent side to side rocking of the engine at the proposed tick over of 900 rpm.

With increased revs this smooths out, but back at tick over and off we go again.

Has anybody seen this before and got any ideas before I start some serious testing.

Regards

Dave

Post by **fairwynds** » 14 Nov 2008, 17:21

that'll be your engine mountings. I had same problem. New mounts cured it straight away.... hang on I'll find a pic.....
FW

Post by **fairwynds** » 14 Nov 2008, 17:27

an low....... engine moutings (rear). The front one is at forward end of gearbox, its also worth changing but is less significant in the sideways 'shakes' !

[IMG:160:120]http://i98.photobucket.com/albums/l261/ ... MG1742.jpg[/img]

Post by **fairwynds** » 14 Nov 2008, 17:30

and fitted to the van.....
[IMG:640:480]http://i98.photobucket.com/albums/l261/ ... MG2302.jpg[/img]

Website · Post by **syncrosimon** » 14 Nov 2008, 17:38

fairwynds wrote:and fitted to the van.....
[IMG:640:480]http://i98.photobucket.com/albums/l261/ ... MG2302.jpg[/img]

Beautiful, just beautiful.

Website · Post by **CovKid** » 14 Nov 2008, 17:40

Cripes, you under there every day or something? You could eat your dinner off that. Love the antigued stressed look to CV joints too - nice touch.

Post by **nenenaiad** » 14 Nov 2008, 18:05

Thanks for that. Could you confirm what you found when trying to set the tick over / mixture so that I can compare the symptoms.

Many Thanks

Dave

Post by **HarryMann** » 14 Nov 2008, 18:14

But I would also check the compressions if you cannot get it to idle at the correct CO...

Oh, and the tappet settings...

Also an indication that the spark cannot fire a weak mixture, so check your plug conditions and gaps if you haven't done so for a fair mileage.

Post by **HarryMann** » 14 Nov 2008, 18:16

Love the antigued stressed look to CV joints too - nice touch.

Whaddya mean, that pure gold plate on those CVs

Hope that's silver paint or lacquer so it doesn't corrode! but whatever, it does look nice...

Post by **billy739** » 14 Nov 2008, 19:25

sounds like a misfire too me!

from cold start it up and let it tick over for 10 seconds , switch engine off , then try to touch the exhaust where it bolts too the head .
they should all be of the same heat , the cold 1 or 2 indicates a missfire!

once you figure which one we can progress from there.

but like stated above check the mounts ,sometimes the bolts can be loose or missing !

Post by **HarryMann** » 14 Nov 2008, 19:29

but like stated above check the mounts ,sometimes the bolts can be loose or missing !

Yup, or just broken!

Website · Post by **syncrosimon** » 14 Nov 2008, 19:33

You can do the same with a garden water sprayer, just give it a dose all over the pipes, it really is very effective. then you can do it with a hot engine if needs be. Just fire up, and with a torch observe how the water burns off.
A mist around the spark plugs can also show up a spark leak, as can observing the engine in the dark, looking for little sparks around the plugs.

Post by **lambrettalee** » 15 Nov 2008, 18:38

blocked or possibly the wrong idle jet on that weber carb....

Post by **fairwynds** » 16 Nov 2008, 18:51

misfire....? yup, had one of those too (so mine couldve been either/or/both problems....judging by others advice here) My no1 cylinder had a burt valve which caused a loud misfire on the overrun....
[IMG:640:480]http://i98.photobucket.com/albums/l261/ ... MG1792.jpg[/img]

Post by **nenenaiad** » 17 Nov 2008, 00:32

Hi,

I thank you for all your comments. I tried to get near enough to the correct CO and took it in for an MOT retest. This indicated the the
Hydrocarbons were way up and that therefore there must be some form of air leak on the manifold.

I removed the carb and all mounting plates, cleaned and re sealed them, with nothing untoward being found.

I then deliberately kinked the servo vacuum feed pipe and noted an immediate change in engine behaviour between normal and kinked.
I removed the pipe in question and put it under pressure and under water and low and behold it was really porous.

The piece of pipe is the piece from the manifold to the non-return valve on the servo line and is braided and metal reinforced.

This was replaced and I am pleased to say the problem was solved.

Thank you for all comments.

Regards

Dave

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Re - 1.9 Water Cooled Petrol Engine - Rocking on tick over

Re - 1.9 Water Cooled Petrol Engine - Rocking on tick over

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1.9 Petrol Engine - Rocking on Tickover - Resolution