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MG TD TF 1500 - Hot coil?

Took the TF for a great in drive today. Was warm and the car was hot, almost 110 C. Stopped and let it cool. After about 15 minutes, the car would not start, turned over, but would not start, engine did throw quite a bit of heat still. After about half an hour, 45 minutes, car started right up in ran beautifully. Why? Is my coil starting to go?

Todd
TR Hammond

No way to know without changing the coil, unless you have the means to do a hot/cold test. My first suspicion would be vapor lock. Next time it happens, try pulling the choke and see if it starts more easily. If so, then next time you park it hot, try leaving the bonnet open until you're ready to start it again. 110C is really hot! That could definitely cause a fuel vaporization issue.
Steve Simmons

Todd,

I had a similar thing recently with my TF1500.

The coil got quite hot and the car was misfiring. Finally, the car would not fire at all.

Checked the points and found no spark. Condenser was the culprit! This decline happened over several weeks.

Fitted another Condenser and the engine fired up straight away and ran evenly.

Cheers
Rob Grantham
Rob Grantham

110°C is enough to cause vapor lock in fuel system but it is also enough to cause vapor in cooling system.

Could be many thing with such a temperature.

Where did you measure this temperature ? Engine bay, head, radiator top, water hoses...

Laurent.
LC Laurent31

Sounds like a classic case of vapor lock.
JIM N

Seems like vapor lock is what the popular answer is. I replace the condenser and points recently, so I don't think it's that. It was a very warm day, the car ran warmer than it has in a long time. The temp was what I read on the temp gauge. I have had this happen only a couple of times. Thank you for the help.
TR Hammond

If you get the “no fire” symptom again, try starting the car with the choke engaged. I have not figured out exactly why on the XPAG’s will start every time with vapor lock.. but they do..and after it runs for a few minutes (by the time you leave the parking lot) you can push the choke off and run smoothly all day.

Regards, Tom
tm peterson

Check that the gauge sensor is OK : add a reference thermometer in the top of rad.

Ok for pulling the choke if the engine happens to stop due to vapor lock. But first you have to find why the engine is so hot : thermostat, pump, radiator, mixture, ignition timing.
You may get into much more trouble with such a temp.
LC Laurent31

MG switched from mounting the TF fuel pumps on the firewall (called that for a reason) where they sucked gas uphill from the tank, to the rear where it pushes it up to the carb and avoids vapor lock.

From the sounds of it, I'd bet yours is up front on the firewall.

The sound of the firewall mounted pump clattering away at full speed is a dead giveaway it is trying to pump fuel vapor up the heat soaked fuel line in vain.
JIM N

This thread was discussed between 31/05/2022 and 05/06/2022

MG TD TF 1500 index

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