Poor Gas Quality = Poor Running?
 

Guys,
Sorry for this long post:

About a month ago I sidelined the Silver Banshee because of an engine miss problem. Some of you may remember. THe first thing I did was add two bottles of FI cleaner and ran the piss out of the car to no avail. I then began a systematic check of ignition and FI. I ended up replacing cap, rotor, plugs, wires, installing an Ignitor, flow checked injectors, etc. One day, after installing all this new stuff (and along the way I checked for improvements with each replacement/upgrade) I started the car and it ran rough/missed etc. I began jabbing the throttle repeatadly and all of the sudden, it smoothed out and we were back to normal. I drove the car for a week. One day, mysteriously it began missing, not idling, poor power, etc. I thought, crap! Something is really wrong with the FI! Well, that was last week. I remembered that the car ran fine to the point that I filled it up at the local Shell station (where I buy all my gas). Today, I dumped in a jar of FI cleaner and let it idle at 2000 RPM for 20 minutes, got it warm, checked the timing and it was OK. I began revving the car and slowly, she began to run smoothly and the miss went away. I took it for a spin and its fine. What's up with the gas so that it causes this kind of thing to happen? It was fine on this fuel all summer.

Thanks,
Troy

Well, it seems odd that it would be somewhat intermittent on the same tank of gas, but it's possible. It's also possible that the filter in the gas tank or the external filter became clogged. You may want to check the inside of the tank to see if it's full of crud, maybe replace the pickup sock while you are in there. Also couldn't hurt to replace the fuel filter if you haven't already.

Bad gas can cause a car to run horribly, my wife had to change gas stations because her car ran so bad at her usual station.

Steve,
In both cases, after putting a good FI cleaner in the tank, I was able to clear the blockage, get rid of the water, or whatever and get back to running condition. If it was a plugged injector, I would have seen it in the flow test I did. Is it possible with the winter additives, like alcohol; junk or water is being suspended and carried into my fuel system? I plan on changing stations but was looking for some explaination of what MIGHT be going on. Also, my old FI bug hated cold whether due to what appeared to be condenstation that would build up. I put HEET in the tank of the bug and she'd run fine til the next fill up. I was wondering if something like that was happening with the 911. If so, my dear wife called it a month ago. I spent $250 on new parts (which I was glad to get). She said, "try a bottle of HEET first". She's too smart for me.
Troy