1974 w115 230.4 problem cold idling, sooty plugs, running on2 cyls

[wallopadonkey]

runs terribly untill hot then still rough
should this be like a sewing machine or are they lumpy
changed leads rotor arm dizzy cap car rebuilt a few months ago new seal etc

took off the 2nd lead from back and front nearest the fan and still ran the same

timing lamp not getting a signal regularly however the timing we think was at 30 degrees tdc nit is around 15 degrees then the engine gets hot and it tick over rough but no stalling

gonna try the condensor today contacts are very clean but not new gap set to 16thou
plugs gap correct all firing

worth trying a new coil?

i cant find much info around or a workshop manual any ideas fella and of course ladies

ta
dave

 

[jibcl500]

Do a compression check before spending more money, low compression can look like a misfire.

jib

 

[wallopadonkey]

ok compression 11 bar accross all four pots garage say it is fine
still running crap

where good place to get brake stuff from as fronts are binding
rear offside not operating rear nearside 60 % efficient hanbrake 0% lol


thanks for this
dave

 

[Aussie Nick]

I think this is a preinjection model. If it is I would suggest that the problem is in the carb running too rich a mixture. Before you go any further would suggest that you try some carb cleaner down the throat. Subaru make a very good one which will also clean out injectors and decarb the head.

 

[mr rosher]

runs terribly untill hot then still rough
should this be like a sewing machine or are they lumpy
changed leads rotor arm dizzy cap car rebuilt a few months ago new seal etc

took off the 2nd lead from back and front nearest the fan and still ran the same

timing lamp not getting a signal regularly however the timing we think was at 30 degrees tdc nit is around 15 degrees then the engine gets hot and it tick over rough but no stalling

gonna try the condensor today contacts are very clean but not new gap set to 16thou
plugs gap correct all firing

worth trying a new coil?

i cant find much info around or a workshop manual any ideas fella and of course ladies

ta
dave

hi dave have you got the right leads on the right cylinders, just a thought
rod

 

[jaymanek]

This will be a carb issue... I used to have the M115 engine in my W123 and I must have rebuilt the carb at least five times.
The M115 engine is hard to tune in combination with the stromberg 175 cdt..

You may be better to get a refurbished carb or buy yourself a refurb kit, available from any carburettor supplier and rebuild the whole thing.

Also the choke mechanism gets quite worn... you have to take it apart to see whats going on inside. Various springs and coils and if any of these have rusted or broken they need sorting...

I would say that your primary issue is a little plunger inside the choke that enriches the mixture has got stuck open and the car is running too rich and not retarding away once hot.
there is a stepper inside the choke too, if the edges of these steps have rounded off then the choke will not be working.. i used a file to put the edge back onto them..

Its difficult to explain, once you start taking it apart you will see what i mean.

Also check all seals are tight, no vac leaks... the rubber mounting bracket usually cracks letting air in the engine without going through the carb..

 

[wallopadonkey]

oh yes it is a carbed model

briliant is there a rebuild guide about for the stromberg i figured sooty plugs was to rich but previous owner said it had been rebuilt so figured it was ok


is it normal to have play between moving the crank and the cam moving like the chain is loose or something is there a tensioner in there somewhere

also is there another carb to put on to get me rolling untill i can get the carb sorted/save for a rebuild

ta
dave
also brake pads and flexible brake hoses do we have part numbers or anything having trouble tracking down information

 

[jaymanek]

no there shouldnt be any play...

I dont think there is a specific guide anywhere.. I used my brroklands manual for setting up info and as for rebuilding the carbm its fairly self explanatory..

take it apart, remember where things go and replace anything rubber or paper..

 

[wallopadonkey]

http://cgi.ebay.co.uk/STROMBERG-175...oryZ9903QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

would this do as it is real close to my house??

dave

 

[jaymanek]

there were so many variants of the carb..for different models and options.. you need to get them side by side and compare the components.
also thats just the basic carb, i suspect your issues stem from the choke.

 

[dean36014]

I used to have an old Sierra diesel with a worn timing chain. It never ran right, smoke badly, down on power etc. I replaced the timing chain, and what a difference, smoother, no smoke and alot more power. If the chains badly worn, and the tensioner can't take up all the slack, the engine timing will vary wildly. Mind you, I agree with the above posts and would start with checking the carb.

 

[wallopadonkey]

thanks for this guys much appreciated
strip down tonight and will take loads of pics to see if anyone can spot anything untoward lol

will look at chain and tensioner however car has fsh up to its shown 55 k miles so more likely lack of use than wearing out i think it done 12 miles in the last 5 years we will see!

ta
dave

 

[jaymanek]

tensioner wears with age rather than mileage

 

[vijilants]

This engine is dead simple to work on -

For the mixture problem:

Open the top of the carb (3 or four screws) and remove the top. when you take the top off you will see the piston which holds the needle valve. around the piston is a rubber seal.

Check the rubber seal properly for any perforations.....If there are any, replace it. This a a common problem on this carb that makes it run rich.

Remove the piston and clean the needle valve.

Replace all the parts and fill the resevoir at the top of the carb with automatic transmission fluid.

If you have a CO meter, these are not too difficult to adjust.

First adjust the butterfly valve until it is fully closed. You can feel it bite. Then rurn the screw 2 1/2 turns in so that it opens.

Check the CO level - should be about 2% if I remember rightly.

It is adjusted from below the carb.....there is a nut directly in the middle of the float chamber under the carb.This nut moves the jet up and down.

Tigtening it reduces the fuel and loostening it allows more fuel.

Stripping down the carb, cleaning everything and replacing all the gaskets will make the world of difference.

Also fitting an inline fuel filter will stop a lot of dirt from entering the carb.

Regarding the timing chain / tensioner, you should hear it start to rattle before it goes. However, best to change between 60 - 80000 miles.

 

[wallopadonkey]

thankyou for that really helpfull
back from holiday now so back to the welding and will take off the carb this weekend i think strip down rebuild time
dave