Sick CIS - diagnostic suggestions?

[phaques]

I guess this is going to be the winter I learn to work on my CIS...

Here's what happened, and then I hope some of you CIS magicians will have some idea where I should start (my car is an 83SC with the stock 3L):

At VIR this past weekend, I ran low enough on gas during a session on track to gulp some air - and other bad stuff, I'm afraid - into my fuel system. Two times I think the motor sucked air. Immediately after the second time, the car started running like cr*p. Back firing under load, throttle cutting out and in under load, rough running and backfiring at idle, engine stopping and then hard to start, and everybody who listened to it agreed it sounded like it was running on only a few cylinders.

I let the car idle for about 10 mins, and then took it out in the next session - after adding new gas - and limped around the track for about 4 laps, car burping, backfiring, and running terribly.

At idle, I removed spark plug wires one by one to see what effect that had, and in apparently four of the six cylinders, it had almost none.

I took off the fuel filter and drained it to see what was inside, and I swear it looked like apple cider - dark and full of lots of particles of stuff. No water separating out though, as far as I could see. This filter has less than 8K miles on it, and is about 18 months old. I tried to salvage the filter by filling it backwards with clean gas, sloshing it around, and dumping it out the inlet side - waste of time. I re-installed the filter, started the car with great difficulty, and drove it around the paddock to the horrified stares of everybody I drove by, and then coaxed it onto the trailer and came home.

So...my assumption is that the car sucked some gunk into the fuel system when I ran it too low on gas. And my question is..

What would you do, and where would you start?

[cab83_750]

bumparoni!

Not an expert here but:

1. I would have bought and installed a new filter.
2. I would have uninstalled and cleaned the gas tank.
2. Added some super-strength fuel additive.


Some people have warned me about running low on gas causes all the crap to get sucked-in. I guess this is not an urban-myth.

BTW, sorry about your issue.

[phaques]

Yeah....airplanes have sump drains installed in all the gas tanks, so you can drain the crap out and look at it before every flight....I wonder if such a thing exists for auto gas tanks?