LT1 running rough???
Posted: May 20 2008 02:05 PM
1996 LT1 with a 4L60E trans (set up by Street & Performance) out of a 1996 Impala SS. The engine has 9500 original miles on it.
Here's the problem.....start it up, hit the highway and cruise at 65 mph (190 degrees). Smooth and responsive until coming to a stop. After idling in traffic or at a light for 30 seconds or more it starts to run rough as though starved for gas. Temperature remains at 190. After parking for a few hours where everything cools down it runs great again until the first idle/stop situation.
I suspected moisture in the fuel but no amount of Sea-Foam/Heet with fresh gas helps any. I next thought maybe fuel vaporizing in the fuel lines somewhere but cannot find any lines running close to the exhaust system.
It runs so good otherwise that I cannot believe that it is an electrical problem as suggested by a GM mechanic. He also suggested that I check the injectors. Why, I asked, as it runs smooth until that first stop (remember, it doesn't start acting up until the first stop, no mater what the distance it has been driven). It will idle all day on my driveway and never miss a beat. And, even with the gas prices where they are, I took it on a 30 mile test drive and it ran great until I got off the interstate. Once again it atarted running rough. I managed to get it back on the interstate to head home and had to "nurse" it the full 30 miles back.
Anybody else ever run into this? Suggestions or ideas will be much appreciated. |
