Just came back from running all over town this morning, then after a car wash and a day later, I still can't get the car to keep running. I've checked everything basic: Oil, plug wires, choke, antifreeze and even removed and put back on the vacuum lines to the carb and I still get this order of events, coupled with a really hard re-start attempt.

The car has been idling rough (shuddering) at traffic lights for a month or so (getting increasingly worse) so I figured something must have been on the blink and then died. I'm over my head now. I just changed the fuel pump in December, so that can't be it. I wonder if the diaphragm on my Stromberg 175 CD might have worn out (I rebuilt the carb a year ago February)

If anyone has any remote idea as what to check next before I call my mechanic and transfer the problem, I'd much appreciate it.

Thanks Guys,

AARON ROCHARD

1976 230 (4 Cyl Gas)

I would have to think it could be something in the ignition system. I would check in the area of the distributor and soforth.

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Benzmac:
Donnie Drummonds
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Could this possibly be the symptoms of the coil going bad, or maybe the compressor (attached to the distributor) or maybe the points. (As I have no sure way of measuring the functionability of these parts from lack of tools, I would rather try replacing parts first.) I'm certainly no mechanic, but I'm sure I can figure out the problem through replacement.

The only thing in that area that I haven't changed since I bought the car is the coil, so I guess I'll start with that.

Thanks again,

AARON

1976 230.4 W115

Hi there,
Have you checked for condensation in the distributor cap? It could be a definite possibility condsidering your symptoms. Another thing I would check is the resistance of the spark plug and distributor - coil wires. You should measure from about 9,000 ohms to no more than 20,000 ohms through each wire. If any of them measures infinite, or open, you have found a problem! Many new wires will fail soon due to the poor ends they install these days on aftermarket wiring kits. Another thing to check for is any signs of carbon traces around the high tension socket on the coil. Try replacing the condensor, they are cheap. A last thing to check is the point gap, if it has points. The gap should be such that the pattern the wiper arm makes on the points cam is about evenly divided between make and break. The car will always run smoothly if the pattern is in that area. If the distributor shaft bushings are worn badly it is sometimes difficult or impossible to make an engine run well.
Richard Wooldridge

I had an oil diaphragm failure on my 1980 MGB's Stromberg carb, and it would sputter, but had complete lack of power, replacing it was easy and it fixed the problem, but I don't know if this would apply to you as it seems like the car just can't stay running.

My MG would die when the diaphragm was bad, but it had so little power I had to crawl home.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

Thanks for all your responses. I have the coil on order, and tonight, I'll go under the distributor cap with a blow dryer and see if it helps.

I'll keep you all posted.

AARON ROCHARD

1976 230.4 W115

Have you checked for water in your fuel?

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

I thought that to be a possibility, but I had just filled up the day before, and I'm always using gas line antifreeze. Should the problem persist, a little water remover wouldn't hurt.

AARON ROCHARD

1976 230.4 W115

Just tried the blow dryer and cleaned the plugs and still the same reaction. It ran for about thirty seconds then choked and died. Also, the garage filled with a lot of smoke (black I think)

Correct me if I'm wrong, but my guess is it is once again that confounded Stromberg Carb. I'm already looking into a Weber conversion kit on the net.

Please let me know if this sounds about right to you guys as well.

Thanks,

AARON ROCHARD

1976 230.4 W115
(With a migrane Stromberg 175 CD Side draft piece of garbage carburetor !!!)

Hi there again,
How long has it been since you replaced the diaghram in the carburetor? I'm refering to the rubber diaghram that operates the slide valve, it's about 4" in diameter, and MUST NOT HAVE ANY HOLES IN IT. They only cost around $6.40 here, and I replace the two on my Jag yearly, just to be safe. They have to be in good shape to allow the slide valve to rise. If it doesn't rise in response to the vacuum increase on the intake side of the slider, the car will run VERY rich and will have NO response - it will hardly go above an idle, or in your case it might even die due to running too rich.
One time when I needed one in a hurry I made one out of a piece of thin player piano cloth - they cloth I used was left over from recovering our reproducing grand piano pneumatics, and was nylon cloth reinforced neoprene, probably was a better quality fix than the factory rubber.
By the way, be sure not to overfill the oil resevoir, the excess oil ends up on the rubber and causes it to deteriorate. I always use Marvel Mystery oil in the resevoirs at the direction of the Jag factory manual.
Richard Wooldridge

Hmmm, not a bad idea, its been a year since I had the carb re-built, maybe a new diaphragm is in order. I'll give it a try. If I can delay the expense of a new carburetor, that's be nice.

AARON ROCHARD

1975 230.4 W115

Well, I just partially took apart the carb. Replaced the diaphragm, checked the choke and sprayed it with WD40. checked the coolant flow to the choke (water choke). Cleaned and replaced the plugs and checked for anything out of the ordinary.

SAME REACTION ON STARTUP

In idle: cough, sputter, dead (even after giving it some gas)

Oh, and LOTS of smoke) black.

I will proceed and replace the coil and condensor, but my primitive mechanic skills tell me that the carb is probably DEAD.

Now www.webercarburetors.com has my conversion kit for:
$495 !!!

Does anyone out there know of a cheaper source ?

Thanks,

AARON ROCHARD

1976 230.4 W115

When all logical checks fail, I look for something stupid that has happened. If this problem has been creeping up on you, perhaps the distributor clamp has loosened up and permitted the distributor to slowly rotate to the point where the timing is seriously out of spec. This actually happened to me on a Porsche that I once owned. It is an easy thing to check and fix. If the distributor body can be rotated by hand, that is the problem.

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

Argh ! Well, I did the idiot check and unfortunately, I'm not so lucky as to have found a problem. I took apart the carburetor, replaced the diaphragm, pulled off and checked the choke to see if its sticking and nothing wrong there.

I will replace the coil and the condensor on the weekend and see. The engine is definately flooding, though. The fuel filter I have is quite full with gas (more that usual)

I wonder if the coil and condensor replacement doesn't work, if I may have a serious Vacuum problem. I have a vacuum tank in the trunk on the passenger side and a charcoal cannister, providing some vacuum to the carb.

Have any of you had any bad experiences with these things?
Can the cannister be re-built or does it need to be replaced ? What about the Vacuum tank.

Thanks again for all your input, I WILL FIND THE PROBLEM !

AARON ROCHARD

1976 230.4 W115

Hi there,
Your vacuum tank couldn't possibly cause your problem. Ditto with the charcoal cannister. The problem must be that the float needle and seat are not seating. This could be due to a damaged float, or a worn needle/seat valve, or contamination. If you take the bottom cover off the carburetor, you will expose the float, needle and seat. Carefully remove the float pivot, and unscrew the needle valve assembly. Make sure that it seals completely with a very light pressure on the needle. Make sure that the float has no holes and really does float. You can test this in a pan of water, also it should not have anything in it if you shake it. The floats on my Jag are made of brass, but if your float is foam, be aware that foam becomes saturated with fuel over time and doesn't float anymore. There is a fuel screen behind the carburetor's fuel inlet fitting. Remove the fitting and the filter screen, and make sure it is in good shape! Make sure that the float aligns with the base of the carburetor when it is turned upside down - the float should be about level when the fuel level is correct. There should be about .65 - .67 in. clearance between the float and the body of the carburetor. (16.5 - 17mm) If adjustment is required, be sure to only bend the little arm that contacts the needle. Both sides of the float should be even, and the float should not rub on anything. After assuring yourself that all parts are clean and gaskets are good, reassemble the carburetor. I think this should take care of your problem. By the way, you haven't replaced the fuel pump recently, have you? A too-high fuel pressure will cause big problems with this carburetor, it is designed for about 4 psi only. For example, if you got hold of a high pressure pump designed for fuel injected engines, you would most likely end up with a flooding problem. My Jag book has a very complete rebuild info for this carburetor (175CD2SE is what the Jag uses, same carb but throttle linkage for two)
Good luck with it,
Richard Wooldridge