Question about 1999 Chevrolet C2500
Multiple misfire of cylinders (p0300) indicates a systemic timing fault. A key component central to the engine timing is the crank sensor. It can be tested but it needs and oscilloscope perhaps easiest and cheaper to change it for a new one (approx $30 and 20 minutes).
Before doing that it would be prudent to do a general check over. Start with the spark plugs, remove them one at a time (to avoid mixing the firing order up) noting the gap, overall condition and colour. Now check the leads and plug connectors, there should be no signs of shorting through the insulation and the wiring should be clean. Now check the low tension supply to the coils, make sure that the wiring loks good and that the connections are clean and bright. Always disconnect and reconnect socket/plugs a few times as this can help freshen the contacts. Now check the starter fuse and starter relay. If you wish to, remove the cover on the starter relay and check the circuitry for condition and note the state of the solder joints. If you see a dry joint just resolder it.
One other area, not electrical, worth checking is the overall state of the EGR assembly, especially the port supplying exhaust gas to it. Even partially blocked this can lean out the fuel mix to make ignition so hot as to misfire.
Once you have checked over the things you can see it is time to think about changing the crank sensor.
Posted on Sep 13, 2010
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Jun 27, 2015 | GMC Cars & Trucks
Apr 21, 2015 | 2001 Honda Odyssey
Feb 25, 2014 | Chevrolet Cobalt Cars & Trucks
Sep 06, 2012 | 2005 Jeep Liberty
Jun 26, 2012 | 2002 GMC Envoy
Aug 17, 2011 | Dodge Charger Cars & Trucks
Dec 16, 2009 | 1998 Chevrolet S-10 Pickup
Sep 17, 2009 | 2002 Dodge Dakota Club Cab
Aug 03, 2009 | 2004 Chevrolet Silverado 2500HD
152 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: