I would like to share a couple of my experiences with you

[RayInAlaska]

I would like to share a couple of experiences I have had with my 1988 GMC Sierra step-side (350 TBI, with a 5-speed transmission. Those experiences are as follow:

a. About a year ago when starting the motor on cold days, the motor’s RPM would be just about 1,000, and then drop off like the motor didn’t want to run. I would then hold the gas pedal down to increase the RPM to around 1,200 and hold it there for about three minutes. After that the RPM would stay up as normal, and then drop down to low idle when the motor was warm.

If I didn’t do that the motor would idle rough and the smell of unburned gasoline could be smelled around the truck. I replaced the temperature sensors and tested their respective leads, and everything was fine, but the problem persisted.

Believe it or not the fix to this problem was a can of Seafoam in the tank, plus another can on another tank full a week later. Now the HI or LO idle are nice and steady, and I don’t have to hold the gas pedal down at the beginning to keep the motor running.


b. The second experience is as follows: a few days ago after the truck had been parked for a few days which temperatures around -10 degrees and colder. I started it and drove the truck or a few miles on some errands, and then parked it.

The next few days the temperatures reached the high +20s during the day. Right in the middle of the warm spell three days ago I decided to start the truck to drive it around some more, but this time the motor turned and never started. The battery was good, so the starter cranked the motor quite fast; I tried several times to start it, but nothing happened. It acted as if the there was no fuel reaching the TBI, so I decided to leave it alone instead of overheating the starter.

I have had at least one experience like that in the past, and it’s something very common in the interior of Alaska where it gets very cold. This problem is more common when the temperature reaches the high 20’s and low 30’s after a very cold spell of subzero temperatures.

Well, I thought about it and figured that there was a good chance that some moisture in the tank had turned to ice when very cold and blocked the fuel line somewhere, which all the freezing and thawing in recent weeks. It seems that was the problem this time, because yesterday I poured another portion of Seafood in the tank, followed today by a red color can of Heet fuel dryer. I let it sit all day today, and just a few minutes ago the motor started without a hitch. The temperature is around +26 degrees outside (yes we are having a wonderful winter this year)

[speedygonzales]

What is the amount of ethanol in the fuel you use?

[special-K]

My guess is the fuel froze. I think that's what Speedy was gettin' at. Ethanol or not, your system managed to get enough moisture in it to be an issue. Even though it warmed up, it wasn't over freezing, and even if it was 70 it would take longer to warm the tank of fuel. There are SOS additives that should help. I doubt it's so bad you need to drop your tank.







.................................................................................................... ................... (I hate ethanol)

[RayInAlaska]

Originally Posted by speedygonzales

What is the amount of ethanol in the fuel you use?

No ethanol is used in Alaska. But it seems that when extreme temperature fluctuations happen, a lot of people have the same problem, specially during the warm temperature spell. The reason for my post is the hope that other people living in places where it gets very cold become aware of this problem. By the way, the fuel in the underground tank at the pump is usually a warmer than the fuel in the truck's tank, at least during the winter months in Alaska.

In here we pour a can of Heet in the tank a time or two per month. But I have had good results with Seafoam every time the idle gets a little rough or unsteady.