Have small 2000 Blazer SUV with 4.3. I will be driving along at 65 miles per hour and suddenly it will feel like it sucked water in the gas line, coughs twice,and then it is fine,Still running at 65. Gauges don't flicker, No check engine light. The other pecularity is that it typicially shows up at 1/2 tank. Is this a fuel pump going bad? Have changed the fuel filter. Problem persists. Has new plugs and wires. I have noticed that when I remove the gas cap to fill up I don't hear any pressure release. Anyone seen this issue??

 

hello, try a bottle of 'water out'gas treatment from a parts store, you could be right about water in the tank. it was a bad problem in nc a few months back when the price of gas spiked. also try a bottle of fule injector cleaner. 'stp-lucas' see if it helps. you also changed plugs and wires, how about -cap and rotor- if cap is worn on one of the contacts it could cause intermitint problem.

 

Another idea once you run the water out treatment if it helps start running a regemen of every so many fills at the pump. Because I typically fill up 2x a week, every2 weeks or about 4 tanks of gas put inawhole bottle of octane boost.I had the same problem andfound out that because around where I livegethigh humidity and thefact that around here you can't always count on gettin good gas, I started doin this my problem went away and truck runsa little better and I get 1-2 mpg better.

EDIT: Also I found out that alot of guys have problems with these trucks when they run them below an 1/8 of a tank of gas. One day I had to take my truck to the GM dealer for a recall an the techhighly recommended that I never run below an 1/8 of a tank, I have done this though, sometimes it can't be helped but when I rarely do this I get nervous.