I have a 2000 Chevrolet Venture, 3.4L motor. Here is the latest in a string of problems:
The van started hesitating under load. It starts fine, idles terrific. It cruises fine. The "Check Engine" light is not on. But when attempting to accelerate from a stop, or when climbing a hill, the motor feels like it wants to fall on it's face. The problem is that it is intermittant. After trying in vain to troubleshoot, I finally broke and took the car to the local GM dealer. There are no codes. The only thing they could do was connect to the fuel rail and read the pressures. They also took the van for a drive. But of course, as my luck would have it, they couldn't recreate the problem. The van was running flawless that morning. It does seem to get worse towards the end of a "trip".
I've already checked for arcing spark plug wires (engine running at night) and I've cleaned the MAF sensor with electronic cleaner. No difference. The problem is slowly getting worse, but it's still not throwing a code; and of course, every time I try to troubleshoot, it's running perfect again.
The wife and kids are taking a long trip next weekend, and I'm nervous. Please help!!