Another Issue with an Edelbrock 1406

[mrein3]

Have you considered your fuel?

I don't know the laws in GA but here in MN the government mandated 10% ethanol in ALL grades of gasoline sold at ALL pumps here. EXCEPT for specially marked pumps that are to be used only for lawnmowers, snowmobiles, snowblowers, watercraft, and collector vehicles or vehicles eligible to be collector vehicles.

I know ethanol is trouble in my boats, lawnmowers, tiller, ATV, snowblower, etc. I always fill my jerry cans with ethanol free and my small engines always work right. My friends who save 10 cents per gallon by using the same stuff they use in their daily drivers are always taking their small engines in to have carb work done because the gas gets old.

The problem is smaller engines spend a lot of time sitting around. When ethanol sits around it separates and the water in the gas is what causes the problem. If your truck has the same gas in it for 2 weeks or more you can begin to see this.

Again I'm not saying your truck sits around and I don't know what GA does to you guys at the pumps. It just appears that you are doing all the right things and are still having issues.

[long69]

glad i'm not the only one on here that doesn't care for the ole' 1406.
mine ran real fine, but leaked gas onto the manifold.

[dznucks]

Thats a good point about the fuel, that i didnt consider. i really dont know the answer to that or how to figure that out. However i dont think it has any in it. Also, i dont typically use one particular gas station either, just whoever is cheaper. My truck is a daily driver. i go through a tank every week, week and a half.

If this was the case would the engine still run fine at all driving speeds? Keep in mind this only happens at idle. As soon as i crack the throttle the A/F goes back to normal and the vacuum goes back steady.

Today at lunch it acted fine on the way home, but when i cranked it to come back to work it started acting up as soon as i cranked it. It acts like it has trash in the carb somewhere, but i have cleaned it our repeatedly. just for the sake of insanity, i am going to take it back apart and blow all the passages with compressed air.

[CSGAS]

Originally Posted by mrein3

Have you considered your fuel?

I don't know the laws....

x2, plus I haven't noticed anywhere that you've replaced your fuel filter, have you?

I've had to clean out the deposits and crap the "oxygenated" fuels leave behind when they evaporate or sit for a day, got used to rebuilding an old Carter Ball-and-ball every six months in Cali that NEVER got plugged up with anything before MTBE came along.

I submit that your truck sat one day after getting filed up with either "smog" fuel or you ran the tank down to the bottom, stirring up some garbage, then filled it up. Either way your filter sounds plugged and there's probably more junk getting into the float bowl after every time you clean it.

This junk is also possibly sticking between the tips of the rods and jets. Try rolling the tips on a flat, hard surface to straighten them and replace.

Notice that the issues I mentioned can actually arise on nearly any carb, even ones that are normally unstoppable.

[dznucks]

The dizzy springs/weights arent sticking. i thought about that too and checked it. i have had the timing light on its while it acting up and the timing is steady.

The fuel filter is new and its before the regulator and pressure gauge. if the filter was clogged the pressure gauge would be acting funny, but its steady at 4.5 psi. However i do wonder about the fact of the fuel companies switching from the winter fuels to the summer fuels may be causing the issue. over the winter i did add the A/F gauge and really fine tune the calibration. Its night and day difference between the engine of 6 months ago and the way it runs now. this problems just started happening one day.


Its not a rod or jet issue either as i have been moving the calibration around trying to find the right tune. the problem doesnt change with a rod or jet change.

I also thought about the butterfly shaft being loose causing a random vacuum leak. I checked it two days ago when i had the carb apart. It will not move at all while in the closed position. once you open them on up they do have alittle play, but that doesnt explain the idle issue.

i highly doubt it is carb icing. the issue will not start happening until i crank the truck at lunch or when i let it sit for 30 mins to an hour after running it. I dont notice it in the morning probably because the choke and fast idle are kicked in.