November 9, 2021 by Nick Taylor
Real Fixes from Mitchell 1’s SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is available at no additional cost in our ProDemand product.
The following Community Fix summarizes the interaction between members of the community that led to the solution.
Vehicle
2008 Chevrolet HHR SS 2.0L Turbo
Title
Misfire at idle and driving, replaced duct.
Complaint
Customer states engine runs rough and check engine light on.
Diagnostic Steps Performed/Parts Replaced
This car has been sitting for four years. Verified customer’s complaint and found code P0300. When I unplug the mass airflow sensor (MAF) it will idle okay. But when you give it gas it seems like it is plugged up. It is also running rich, the spark plugs are black and it smokes. I can’t check the fuel trims because I don’t run it long enough to get in closed loop. When I did the injector balance test, the PCM only activated the injectors for about 1 second, if that. The fuel pressure only dropped about 4 psi on all injectors. Is that normal? I don’t think it is starving for fuel but will be replacing the fuel today. Any suggestions would be great.
Best Answer from Community Member DAG1365
Check for exhaust restrictions, engine coolant temperature (ECT) readings, fuel pressure readings, and check MAF readings when running. Be sure the grounds are good.
SureTrack® adds to the power of ProDemand® with an exclusive combination of real-world knowledge and powerful diagnostic tools, all wrapped in an interactive community of professional technicians. Designed to help automotive shops increase accuracy and efficiency from diagnosis to completed repair, the industry’s most comprehensive repair information resource is just a few clicks away.
Want more? Here’s how you can get a free 14 day trial of ProDemand:
Not a ProDemand customer yet? Get a FREE 14 day trial of ProDemand by clicking below. It's 100% free with no obligation to buy and no credit card required.
About the Author
Nick Taylor
Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.
2021 Owned and Managed by John Lopez - Mitchell 1 Independent Sales Representative - (504) 289-0953 - john.lopez@mitchell1repair.com