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MG TD TF 1500 - Car will not start

The saga continues...I'm restoring a 1950 TD and am trying to start the engine for the first time in 15 years. I solved the leaking carbs problem, put in a new coil, points, condenser, plugs, plug wires, etc. When I try to start the engine all I get is an occasional gassy cough out of the carb intake openings (I have the air filter and manifold off).

I think I have good spark evidenced by the jolt of shock therapy I received when I held one of the plugs against the block and turned the motor. I notice the carb piston dampers sit in the bottom position regardless of what I do with the choke, wondering if that is normal. Or should they move up when I push the choke in? I tried propping them up a bit to let more air in. I've even sprayed ether into the air intake of the carbs and the cough does turn blue indicating ignition of the ether, but no real sign of the engine trying to fire, no exhaust sounds. Any thoughts?
Robert

Robert,

You said you replaced the plugs - hopefully with new ones? I was helping a friend last weekend with his TC - same symptoms, a cough but no fire. Pulled plug wires and had great spark. Pulled a spark plug, grounded the electrode to the block - absolutely no spark - shorted out internally. He was reusing clean (?) old plugs that were no good.

The other main thing to make sure is that your timing isn't 180 degrees out.

You pistons on the carbs won't normally move until the engine fires. Choking them only allows more gas to come up the jet, doesn't make the piston move as such.

Good luck - it'll be firing soon.

Gene

Gene Gillam

Set the ignition timing to TDC? With new points the timing could be now off.

Was this engine taken completely apart? If so, did you get the cam timing correct?

The carb pistons only respond to the amount of air being ingested. The choke has no effect on them.

<<<snip>>>
I tried propping them (carb pistons)up a bit to let more air in.
<<<snip>>>
This will make the engine even harder to start.

If the engine doesn't fire when using ether, you still have an ignition or cam timing problem. Unless, you have the engine thoroughly flooded.

Blake
Blake

Robert - I think that Gene hit on the biggest problem for first time start, plugs wired 180 degrees out or in the wrong order completely. From your description of the symptoms, I would suggest that you recheck that area. With the timing grove on the crankshaft pully set at the timing pointer on the timing chain cover, check that both valves on #1 cylinder are closed and then see if the distributor rotor is pointing at the wire going to cylinder #1. Once this is established, the rest of the wires should, going counter-clockwise around the dirtributor, go to cylinders #3, #4, #2. Good luck - Dave
David DuBois

I think you guys are right about the timing being 180 degrees out. I tried to adjust the timing following the instructions in the shop manual, but may not have it right. The crankshaft pully on my car does not have the TDC marker hole in it. Instead, it has two notches on the outer edge about a half inch apart from one another. I assumed these represented 5 degrees from either side of TDC, so I used the midpoint as my TDC reference. When you say "closed" valves, would that mean the valve springs would be in their highest position, or lowest?...In the meantime, I'll read up on the subject in my restoration manuals, but I think this is the problem.

Robert

Robert - Closed will be with the springs in the highest position. I would be more inclined to think that the first mark you come to when cranking the engine over is 5° before TDC and the next mark being TDC. Normally the pulleys for the TDs are only marked at TDC. Someone may have added the second mark. Look at them real close, the factory mark will have very square sides to it. Anybody out there ever come across a pulley for the TD with two timing marks on it? Good luck - Dave
David DuBois

Pull the plugs, remove valve cover and dist. cap. Crank (by hand)slowly, and watch valve movement, and piston in plug hole (use flashlight). Bump slowly until #1 and 4 at very top- one mark on pulley should be in line- that is TDC. Cam rotates (valves operate) 1/2 crank speed. Slowly turn, watch valves 1 (ex) and 2 (in). In order, #1 will open (spring down) for 1/2 turn (exhaust stoke), piston going up; next #2 will open for 1/2 turn (intake), piston going down; then both close (compression- 1/2 turn). When at TDC then (both closed and springs up), that is time to fire. The dist. rotor must be pointing to the #1 segment of the cap about this time, with the points just opening. If your rotor is off , it will never run!
George Butz

This thread was discussed on 06/04/2003

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