Loss of power while climbing long steep hill on 2002 Chevrolet Express 2500

Van will shudder and lose power while climbing a long steep hill starts at about 50mph will level out if I take foot off accelerator and re-apply gas at a gradual constant level. Van has 295000 miles. Just passed smog in Oct, runs fine except for loss of power up long steep hills, engine light is off, but memory shows pending code of PO300. Thanks Mark

by in Marina, CA on December 04, 2010
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
2 answers 2 comments
ANSWER by , December 04, 2010
Sounds like basic misfire stuff. Check plugs, wires, etc. P0300 is a random misfire, meaning the computer has not identified the cylinder at fault. Check all plugs and then wires.
COMMENT by , December 05, 2010
Replaced wires and plugs in July, but will check. I replaced the MAF sensor about a year ago. The symptoms were identical maybe I should take back out and clean to see if that helps. Thanks Mark
COMMENT by , December 05, 2010
MAF's cannot cause a P0300. Random misfire is specifically cylinder misfire related. Typically from plugs, wires, coil issue; base engine or injector issue. Or even software... But your symptom just screams of a plug and wire issue...
ANSWER by , June 23, 2011
I had the sam problem an changed the spider injection set