Jason,
Try putting a see through filter in line just before the carbs (I'm talking
about those universal $1.29 specials you can pick up at any parts store) and
see what the fuel level is like as the car dies. This will give you a pre -
post filter diagnosis. Pre filter includes clogs and pump - post filter is a
problem with the carbs. If post filter you can move the filter to isolate
each carb to see what the fuel level to each is doing.
It is perplexing, but you'll get through it!!!
Dr. Doug
69 C Roadster
69 C GT
69 B Roadster
-----Original Message-----
From: owner-mgs@autox.team.net On Behalf Of Jason F. Dutt
Sent: Wednesday, July 16, 1997 1:10 PM
To: MG List
Subject: Still having fuel challenges... :-(
I've sent a message about this problem before, and got some good feedback
that what appreciated. Unfortunately, I'm out of ideas, and the problem
still isn't fixed.
To sum up the situation:
Turn the car on, fuel pump runs, car starts. Car runs for approx. 3-5
minutes, then it behaves as if someone is literally squeezing the fuel
line. It sputters and coughs, won't idle, but will respond (however
pathetically) if the accelerator is depressed. Soon after, the accelerator
will have little to no effect, and the car dies. I can then turn the car
off, then on, and the fuel pump runs like mad (every time), filling up the
float bowls. The bowls must be empty at this point, because the pump runs
for quite a while. I can then start the car again. It will either keep
running indefinately, or die again in 3-5 minutes.
Some more info:
1) It is intermittent. If the challenge surfaces, it will continue until
the car has sat for a while, and then may or may not happen again.
2) It doesn't seem to be affected by temperature, as the car has done this
when cold or hot.
3) The most the car has run since this has started is about two days, with
stops (turning the car off for a while, and then starting it and going
again).
Things I have already checked:
1) Float / Float needle. They didn't seemed to be gummed up, but I
rebuilt the carbs anyway (doesn't hurt, as they were pretty dirty), and put
in a new grose jet.
2) Fuel tank venthilation. I'm not sure if I did this right, so tell me
if there's a better way. I disconnected the hoses from the carbs that lead
to the carbon canister, and took off the gas cap. The car still died.
3) Power supply to the fuel pump. The pump is a newly refurbished SU
AUF300 model. I checked the leads and supply with a voltmeter. The
battery was old and kind of weak, so I replaced it.
4) Fuel line blockage. I disconnected the line at the carbs. Turned on
the key, pump operated. Blocked the flow with my thumb, the pump stopped,
and resumed when I released it.
I'm plumb out of ideas. I want to say its the fuel pump, but I've had that
challenge before (hence the new one), and the symptoms were different. As
I said before, the pump runs EVERY time I turn the key on after the car has
died.
Help please!
Regards,
J
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