Fuel Octane Differences in My Startup!

[dreanmachine]

Let me ask another quick question. When I use auto fuel that is Octane 85, it appears that before that tank is run dry, I start having a bit of a problem in a longer cranking start-up when the 99 EB EXPY is cold. It cranks more then when it is hot (where it generally starts right up). However, when I have run some Chevron injector cleaner through the fuel system and use the Octane 88 or higher at my fill-ups, the system appears to stabilize and I get the engine starting right up on the cold starts. Is this a normal thing? Could there be another problem? I just had a major tune-up with new plugs, etc, but it doesn't seem to have solved this problem. With the price of gas sky-high, and the EXPY liking to drink the stuff, is there any other way around this? Thanks in advance for your expert advice.

 

[monsta]

Where do you live that you can get 85? High altitude area maybe?

 

[dreanmachine]

SLC Utah area. 85 is the standard for low regular Octane, with the leaded plus at 87/88 and premium at 91. The EXPY manual does not recommend the premium.