91 K1500 5.7l studder problem!

red tractor · 11-03-2009, 07:57 PM

When I first put the ethanol gas in my truck it started to studder in the bottom end on initial take off. I was wondering if anybody has had this problem?

BernieB · 11-03-2009, 09:57 PM

You mean E85? Your truck isn't setup to run on that.

red tractor · 11-03-2009, 10:19 PM

no, in oregon they added ethonal to our gas.

BernieB · 11-03-2009, 10:47 PM

Ethanol has less energy, per weight, than gasoline, but the concentration used (typically 5-10%) isn't high enough to really cause any noticeable effect with most properly tuned engines.

On the other hand, ethanol is hygroscopic, meaning it attracts and bonds with water. This is the whole principle behind "dry gas" (which is 90% alcohol). It bonds with any water that might be in the fuel system and lets it "burn" (the alcohol burns but the water flashes to steam and goes out the exhaust). If this is the first time you've used fuel containing ethanol it's entirely possible you had a little water in your tank that the ethanol bonded to and which is now being burned off. Also, if ethanol being added to gas is new in Oregon then it's also possible that the tanks at the station may have had some water in them, with a similar result.

Water in underground tanks is fairly common, the result of condensation forming on the tanks walls when moisture laden air is drawn into the tank as fuel is pumped out. Because the tank is underground it's cooler, and the excess moisture condensates out. Most stations have alarms on their systems to show when there's any appreciable amount of water in the tanks (the gas floats on top, being lighter) and anything more than a couple of inches has to be pumped out. (That was something we did weekly at the station I managed, using a hand operated pump that drew from the very bottom of the tank)

In any case, assuming this is something new in Oregon, then it might take a couple of tankfuls before all the water is completely out of the system.

BernieB · 11-03-2009, 10:53 PM

Oh, and I always used to laugh when people would accuse us, or other stations, of "watering down the gas". Since gas and water don't mix adding water to a tank full of gas serves no purpose. The pumps are going to draw from the top down, and until the gas runs out and the pumps reach the water level you'll get 100% gas, no water. Once the gas runs out though you have the opposite, 100% water and no gas, and the customer is stranded right there at the pump. Which would be a pretty stupid thing for any station owner or manager to want happen.

red tractor · 11-04-2009, 08:18 AM

My truck does the studdering all the time, not just sometimes. Maybe a fuel pump?

red tractor · 11-04-2009, 05:50 PM

I am required to run E10 by Oregon law. They don't allow the sale of pure gasoline for on road use.

scavanger · 11-04-2009, 07:13 PM

Drop in a bottle of Isopropyl alcohol. that will break down the water and burn it. You usually find it in a red bottle rather than a blue bottle.
Once you do that you will know if it is water related.

I have never had a vehicle that ran really well on E10.
Also you might want to run a bottle of dedergent based injector cleaner.
One other thing.. disconnect the ECM or just the battery for awhile to reset the ECM it may need to relearn for the E10. I have an 06 Grand Prix that came out of California. Couldn't get very good mileage. Finally had to unhook the battery for some other reason. Mileage increased from low 25 to upper 27 mpg range.

Scav.

BernieB · 11-04-2009, 08:02 PM

Quote:

Originally Posted by scavanger

Drop in a bottle of Isopropyl alcohol. that will break down the water and burn it. You usually find it in a red bottle rather than a blue bottle.

Considering the amount of alcohol already in the E10, adding more alcohol probably isn't a great idea. Especially on an older vehicle where hoses and fittings might not be compatible with that much alcohol.

scavanger · 11-04-2009, 08:54 PM

The only way to get rid of the water.
Ethonel just puddles the water. Then you get slugs. Isopropyl
actually breaks down the water so it mixes with the gas.
The older vehicles aren't compatible with any alcohol.
Scav.

11-03-2009, 07:57 PM	#1
red tractor Junior Member Join Date: Nov 2009 Posts: 5	91 K1500 5.7l studder problem! When I first put the ethanol gas in my truck it started to studder in the bottom end on initial take off. I was wondering if anybody has had this problem?

11-03-2009, 09:57 PM	#2
BernieB Senior Member Join Date: Jul 2009 Location: Fredericksburg, VA Posts: 1,906	You mean E85? Your truck isn't setup to run on that. __________________ If the guys who design 'em had to take one home, use it every day for 2 years, and do all the maint and repairs themselves, cars would have a button on the dash to change the oil, filters & plugs.

11-03-2009, 10:47 PM	#4
BernieB Senior Member Join Date: Jul 2009 Location: Fredericksburg, VA Posts: 1,906	Ethanol has less energy, per weight, than gasoline, but the concentration used (typically 5-10%) isn't high enough to really cause any noticeable effect with most properly tuned engines. On the other hand, ethanol is hygroscopic, meaning it attracts and bonds with water. This is the whole principle behind "dry gas" (which is 90% alcohol). It bonds with any water that might be in the fuel system and lets it "burn" (the alcohol burns but the water flashes to steam and goes out the exhaust). If this is the first time you've used fuel containing ethanol it's entirely possible you had a little water in your tank that the ethanol bonded to and which is now being burned off. Also, if ethanol being added to gas is new in Oregon then it's also possible that the tanks at the station may have had some water in them, with a similar result. Water in underground tanks is fairly common, the result of condensation forming on the tanks walls when moisture laden air is drawn into the tank as fuel is pumped out. Because the tank is underground it's cooler, and the excess moisture condensates out. Most stations have alarms on their systems to show when there's any appreciable amount of water in the tanks (the gas floats on top, being lighter) and anything more than a couple of inches has to be pumped out. (That was something we did weekly at the station I managed, using a hand operated pump that drew from the very bottom of the tank) In any case, assuming this is something new in Oregon, then it might take a couple of tankfuls before all the water is completely out of the system. __________________ If the guys who design 'em had to take one home, use it every day for 2 years, and do all the maint and repairs themselves, cars would have a button on the dash to change the oil, filters & plugs.

11-03-2009, 10:53 PM	#5
BernieB Senior Member Join Date: Jul 2009 Location: Fredericksburg, VA Posts: 1,906	Oh, and I always used to laugh when people would accuse us, or other stations, of "watering down the gas". Since gas and water don't mix adding water to a tank full of gas serves no purpose. The pumps are going to draw from the top down, and until the gas runs out and the pumps reach the water level you'll get 100% gas, no water. Once the gas runs out though you have the opposite, 100% water and no gas, and the customer is stranded right there at the pump. Which would be a pretty stupid thing for any station owner or manager to want happen. __________________ If the guys who design 'em had to take one home, use it every day for 2 years, and do all the maint and repairs themselves, cars would have a button on the dash to change the oil, filters & plugs.

11-04-2009, 08:54 PM	#10
scavanger Senior Member Join Date: May 2007 Posts: 262	The only way to get rid of the water. Ethonel just puddles the water. Then you get slugs. Isopropyl actually breaks down the water so it mixes with the gas. The older vehicles aren't compatible with any alcohol. Scav. Last edited by scavanger; 11-04-2009 at 09:15 PM.

11-03-2009, 10:19 PM	#3
red tractor Junior Member Join Date: Nov 2009 Posts: 5	no, in oregon they added ethonal to our gas.

11-04-2009, 08:18 AM	#6
red tractor Junior Member Join Date: Nov 2009 Posts: 5	My truck does the studdering all the time, not just sometimes. Maybe a fuel pump?

11-04-2009, 05:50 PM	#7
red tractor Junior Member Join Date: Nov 2009 Posts: 5	I am required to run E10 by Oregon law. They don't allow the sale of pure gasoline for on road use.

11-04-2009, 07:13 PM	#8
scavanger Senior Member Join Date: May 2007 Posts: 262	Drop in a bottle of Isopropyl alcohol. that will break down the water and burn it. You usually find it in a red bottle rather than a blue bottle. Once you do that you will know if it is water related. I have never had a vehicle that ran really well on E10. Also you might want to run a bottle of dedergent based injector cleaner. One other thing.. disconnect the ECM or just the battery for awhile to reset the ECM it may need to relearn for the E10. I have an 06 Grand Prix that came out of California. Couldn't get very good mileage. Finally had to unhook the battery for some other reason. Mileage increased from low 25 to upper 27 mpg range. Scav.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
88 k1500 Overheat problem repalced evryhting! still not fixed! HELP!!!!	.ben	Chevy Truck Forum	18	11-12-2009 05:31 AM
AC & Heater Control Problem 91 K1500 Silver	jbbarry	Chevy Truck Forum	14	10-22-2009 08:12 PM
98 K1500 4x4 Problem	mikemitchell_20	Chevy Truck Forum	24	12-28-2008 03:03 PM
92 k1500 A/C problem	sport	Chevy Truck Forum	1	06-28-2007 07:53 AM
90 k1500 tranny problem solved	smokensteve	Chevy Truck Forum	3	02-19-2007 06:14 PM