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Post by colin on Dec 20, 2023 21:28:52 GMT
Hi,
My Mk 2 is running well, but if I drive along at a steady 40 - 50 mph, then decelerate for a stop sign, the engine cuts out. Any ideas what I should look at first, please?
Colin McCulloch
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Post by Penguin45 on Dec 21, 2023 19:02:43 GMT
Hello Colin.
Is it a clean cut out or is there sputtering or juddering? If it cuts out cleanly I'd be suspecting something electrical; otherwise perhaps to do with fuelling. Does it re-start easily afterwards?
There's a few things to try and work through!
Chris.
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Post by dave1800 on Dec 22, 2023 1:50:38 GMT
Hi Colin As Chris says it could be many things. It is a matter of checking out the fuelling and electrics. For example, it could be dirt in the carburretor (quite likely especially if there is no in-line fuel filter fitted). I have even seen a broken wire inside the distributor cause this as the vacuum advance rotates the contact breaker plate). Fortunately it is quite easy to check everything apart from the ignition coil which is best done by substitution for intermittent problems. You should also check for any vacuum leaks from the manifold, PCV valve etc. (A closed throttle on the overrun raises the manifold vacuum to its highest value so an air leak would weaken the mixture which could lead to a misfire or cut out) If you find something wrong, correct it and test the car again rather than "fix" several issues at once or you may never know the real cause for the next time! I assume you have already ensured the tappet clearance, ignition timing, plug gaps and the mixture is correct. Also check the throttle cable has the right amount of free play and doesn't stick. David Hi, My Mk 2 is running well, but if I drive along at a steady 40 - 50 mph, then decelerate for a stop sign, the engine cuts out. Any ideas what I should look at first, please? Colin McCulloch
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Post by jeff on Dec 26, 2023 10:14:54 GMT
Why not try this for a start: Disconnect the vacuum advance pipe- carburettor to distributor- and plug the rubber pipe at the distributor end. The car won't accelerate as well, but it won't operate the vacuum advance mechanism in the distributor. If it doesn't cut out you can start checking the internal wiring inside the distributor. This has happened to me and I found it to be the flexible cotton covered wire breaking down. If it continues to cut out, check everything as stated by others.
Jeff
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Post by colin on Dec 30, 2023 8:59:42 GMT
Thanks everyone,
Good info. I'll try these suggestions, one at a time, over the next few days.
Colin
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Post by colin on Dec 30, 2023 9:01:01 GMT
Oh, and yes, it cuts out cleanly and restarts first try.
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Post by andrewa on Dec 30, 2023 17:04:51 GMT
I had a similar issue on mine….turned out to be a loose wire on the coil. Fingers crossed it’ll be something simple. Best of luck Andrew
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Post by Penguin45 on Dec 31, 2023 18:20:48 GMT
Further to Andrew's comment, I did have the same issue for a while, which turned out to be one of the large connectors on the starter solenoid. I replaced the connectors and cable in a "belt and braces" repair. See the FIRE! thread for info on how to proceed. Chris.
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Post by colin on Jan 11, 2024 1:33:02 GMT
More on the engine cutout. What is happening is that whenever I put my foor on the brakes - even when the car is not moving - the idle speed drops and the engine stalls. A vacuum problem, I'm wondering....when the brake servo demands vacuum. Any ideas, please?
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Post by colin on Jan 11, 2024 2:27:26 GMT
Disconnected the brake booster and the problem disappeared. Now I just have to figure out where the leak is in the booster. Could it be as simple as the hose?..I hope.
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Post by dave1800 on Jan 12, 2024 1:30:35 GMT
Hi Colin
I assume when you say you disconnected the brake servo that you blanked off the outlet on the inlet manifold. Does the servo hold vacuum after you turn the engine off at least for a reasonable amount of time (several hours). if not then it points to a problem with the non return valve and/or diaphragm. If it does hold the vacuum then this could indicate the fuel mixture is too weak. Haveyou checked the colour of the spark plugs?
David
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Post by colin on Jan 12, 2024 4:47:52 GMT
Thanks Dave. Yes, I did blank off the inlet manifold connection. The engine problem disappeared. When I drove the car the brakes felt no different to before...I'm assuming the problem has been there since I got the car running. Plugs are very light tan colour. How do I check whether the servo holds its vacuum?
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Post by dave1800 on Jan 12, 2024 11:41:54 GMT
After the engine has run and then turned off when you press the brake pedal you should hear a short whoosh sound of air being released. This vacuum should at least a few hours. After 2 or 3 applications of the brake pedal it will cease. I'm curious when you say the brakes felt no different with the servo disconnected, they should have been much heavier and the pedal harder. David Thanks Dave. Yes, I did blank off the inlet manifold connection. The engine problem disappeared. When I drove the car the brakes felt no different to before...I'm assuming the problem has been there since I got the car running. Plugs are very light tan colour. How do I check whether the servo holds its vacuum?
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Post by colin on Jan 12, 2024 18:58:58 GMT
Yes, the brakes have always been heavy since I got the car running. I assume that servo has never been working. I've never taken one apart, and the book instructions look like a recipe for grief. I might take it to a shop, but I want to eliminate any other possibilities.
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Post by dave1800 on Jan 13, 2024 1:35:39 GMT
It does sound like the servo isn't working so you need to keep an eye on the brake fluid level as it can leak into the inside of the servo. The Landcrab brakes are light and powerful when the servo is working properly.You would be better to send it to a specialist to overhaul it if you don't feel cofident to do it yourself. David Yes, the brakes have always been heavy since I got the car running. I assume that servo has never been working. I've never taken one apart, and the book instructions look like a recipe for grief. I might take it to a shop, but I want to eliminate any other possibilities.
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