If the vehicle hasn't been tuned for some time, you may want to check wires and plugs. Also, check for vacuum leaks. Make sure fuel pressure is within specifications. There is a how to check fuel pressure on our home page under the DIY section. Since it is missing when you put a load in it, I feel it is ignition related, but can't be sure until fuel pressure is checked.
Thursday, January 13th, 2011 AT 8:17 PM