[Mgs] Stumbling / stalling ignition issue?

[Paul Root]

Hi all,
	I just got back from a trip to and from work. Less than 20 miles each way. At
about 10 miles each way, I was getting some stumbling.

	The terrain varied, slight incline/decline or flat. Speed was constant,
sometimes a lift off the throttle for traffic.

	The symptoms were 3000-3500 rpm, the tach would bounce down to  1500-2000,
and then back up. A couple of times it dropped to 1000.

	It happened 3 times in a row on the trip home, within about 3-4 minutes, so I
was ready and paying attention. The ignition light did not come on, ever.

	I decided after that to get off the highway and take surface roads the last 4
or so miles. And I got another stall at 2000-2500 rpm. I downshifted to 3rd
and the car restarted.

	At a stoplight, the car did stall. It took 20-30 seconds of cranking to
start. Normally, the car starts within 10 seconds cold, and 2-3 seconds warm.

	I got home without further trouble.

	The car is a 1977 MGB, I have a pertronix distributor, that I put on new last
year. A pertronix coil, that's 8-9 years old. Ignition wires are 8-9 years
old. Dual SU (HIF) conversion.
Alternator replaced to summers ago.

	I'm in the middle of my second tank of gas for the season, I did put in a can
of heat. The oil is fresh, changed last weekend.   Oh, as a side note. I used
NAPA high milage oil. It's made by Ashland, which is Valvoline. Anyway, it was
rated SL/SJ. Not SM. Napa Gold filter.

	I recently put in a plumbing ball valve in place of the stock heater valve. I
don't see any leaking there, but I'll check it again. I do have to pull it
apart, I put the valve in backward for the cable to work.


	I'm going to go and do a fuel delivery test (1 imp qt per minute), and look
things up on Paul Hunt's web site. Oh, and check the rotor and cap.

	What else?


Paul.