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Hard Starting

Hard Starting

I thought I would throw this question out for several reasons. It could make a helpful FAQ for someone else down the road, particularly if, like me, they are inexperienced but willing. And besides, I have the problem. My 140 is a bear to start. I have cleaned the fuel lines, sealed the gas tank, adjusted the carbs and choke (automatic choke switch was replaced with a manual switch), but it usually requires a shot of starting fluid to get it going when the engine is cold. Then it runs somewhat hesitantly (idle around 600 rpms) until it warms up (then it idles at 1,000 rpm). From that point on, I am still cold but the engine runs smoothly. Lately, with the advent of colder weather, starting fluid doesn't help. The starter turns and I may get a cough but no ignition. (When warm, i.e., temp gauge hasn't dropped all the way down, it has always fired right up.) I have fire at the spark plugs and the fuel pump clicks away so it is getting fuel. Does that point (inadvertant pun) to the distributor and points as the next thing to check? Or could this be a condensation problem brought on by colder weather? Thanks, - Jim Voorhies, '55 XK140 FHC

Dear Jim et al., I have had the same problem with my XK 120 OTS and finally found the reason, at least in my case. The two, relatively new, 6 volt batteries were of the wrong type. They were Lucas 6-volt, as specified, but the ampere rating wasn't sufficient to start the car. Once warm, with less resistance to turnover, there was no problem. I discovered the cause when double-checking at the firm that had sold the batteries. They said they had sold them to many Jaguar owners with no reclaimation, but they had no idea if the engines were worn (less resistance) or newly renovated (like mine). The amperage rating is extremely important during turnover. - Allan Derry, 52 XK120 OTS

The timing/points may be off or it could be low compression overall. - George Badger

Jim, I get the impression that the car runs fine when it warms up and also starts and runs fine on the warmer summer days. That being the case, I would suspect a weak spark when cranking the engine; probably caused by one or a combination of the following problems: dead cell in a battery, bad cable connections, weak starter, worn distributor, bad plug wires, improper sparkplugs, bad points/condensor, poor ground on distributor body ,etc. A simple test to see if this theory is on the mark: park your car overnight on an incline, and roll start it the next day, if it fires right away, you know that the starter was hogging all the juice, leaving next to nothing for firing the plugs. If it starts easily inspect and repair/replace all the components previously mentioned. If it doesn't take a compression test or better a leak down test. I don't think you have a fuel problem because you stated that you ether bomb the engine, which certainly would charge the cylinders sufficiently. - Regards, Wray Schelin

I used to have the cold start solenoid disconnected because it seemed to cut out late and I didn't like running rich that long. But I did find it started much better with what seemed an excess of fuel when cranking and so put a switch in to control it. you may not be getting enough, or any, fuel through the cold start thingy. Jim Warren, XK 140 dhc (engine still runs even with the body scattered around the garage)

In addition to other possible causes mentioned already, you might check your coil. They sometimes get weak and produce a colder spark. A quick check can be done by seeing if a disconnected wire will produce an arc across a gap of about a quarter inch or so. Moisture will more likely cause a problem on a rainy day than a cold one. I solved that problem recently on my Dodge by washing the inside of the distributor cap. The electric carb (choke) may need some adjustment - it is not just a matter of working or not working. They can be troublesome. If they worked as well as they could all the time, the cut-out switches wouldn't be so common. I have one, too. How about the fuel level in the main jets? Have you checked the float levels? A lean mixture will cause difficult starting and rough cold running. Have you tried new plugs and are they the correct type? I was amazed at the difference new plugs made with mine. Cured symptoms not much different from yours. - Bruce Cunningham, '53 XK120 OTS

I have to put my two cents worth in. Hard starting can be caused by the following:

1. Low compression 2. Weak coil 3. Shorting condenser 4. Dirty points 5. Shorting cap 6. Dirty connection at cap (pull plug wires and look at the posts) 7. Old sparkplugs 8. Bad plug and/or ignition wires 9. Old gasoline 10. Incorrect timing and/or dwell (35 degrees) 11. Vacuum leak a. Loose bolts on the carbs at the manifold b. Loose connection at the starting carb c. leak in vacuum system to washer bottle 12. No oil in carb dampers 13. Poor electrical connection to coil or between coil and distributor. I've had most of these problems at one time or another. No fun when it won't go! - Cleo Bay, XK120, XK140

Pull the ignition wires out of your distributor cap to see if they are corroded. Repair as necessary. - Steve McDonald

Wray, I can't believe that you didn't mention one of Lucas big problems--a weak coil. Jumpering any substitute is a quick and easy thing to do. Especially when the battery is being drawn down by the starter, a weak coil makes cold starting a big problem. Give it a try and good luck - Larry J

Jim: I agree with the advice you've been getting regarding the hard start; here's a little more. Since you're getting it to start by essentially adding more fuel, (starting fluid) I would be more suspicious of the starting fuel supply than the ignition. In my experience, if the starting carb is not operating correctly, my car is extraordinarily hard to start particularly when it has been sitting for a week or two. I would advise you to make certain that: - the starting carb solenoid is operating as it should, - the fuel passages are clear, - the mixture needle is adjusted properly, and - the "Anti-Blow-Back valve in the Starting Pipe Banjo Bolt" is not stuck closed. (The Banjo Bolt holds the starting pipe to the bottom of the intake manifold. There should be a strong "hiss" out of the carb when it's doing its job). If the solenoid is operating and there's no "hiss" then the blow-back valve is likely stuck closed. Your initial idle of only 600 RPM with the starting carb operating is too low. The Operating Manual recommends a 1000 RPM idle speed when running with the starting carb. - Good luck, Dick Cavicke

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