Question about 2000 Pontiac Bonneville
Car coded yesterday p0303 which said misfire in cylinder 3. if you cold start car it runs fine. But if you stop and restart it idles rough, runs crummy and then the check engine light flashes. recently replaced plugs, wires and coil packs..All help appreciated.Thanks.
The only thing left is the injector or a vacuum leak on the manifold gasket sucking air in and causing a lean condition. Thats is its the only common issue providing you dont have a head gasket issue leaking coolant on that cylinder and the compression and valves are not leaking. The old spark plug should show a coolant issue if present. The white part will be shiney if you have a coolant loss. If the coolant is looking real dark you should have the cooling system checked for gas being pushed into the cooling system on compression stroke thru the head gasket.
Posted on Nov 12, 2009
Try checking the knock sensor and clean the throttle plate inside and out and also the back of the throttle plae, many times the plate sticks from back firing that you can't detect by ear or feel. Also could have a plugged cay.
Posted on Nov 12, 2009
Testimonial: "Thank you for all your help! Where can you find this Lucas treatment? Had a good friend replace the one it is running like a champ again!Thanks alot!"
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:
Dec 08, 2013 | 2000 Nissan Altima
Bad miss at idle?
While stop engine idles like cylinder missing?
Engine Misfire codes for car?
Engine Misfire codes?
Misfire on cylinder 4?
Oil on spark plugs and car misfires?
This will help.
Jan 23, 2012 | 1999 Subaru Legacy
Feb 21, 2011 | 2006 Jeep Commander
A code P0303 may mean that one or more of the following has happened:
Feb 18, 2011 | 2001 Jeep Grand Cherokee
Dec 26, 2010 | Chrysler PT Cruiser Cars & Trucks
Dec 12, 2009 | 1999 Jeep Grand Cherokee
Apr 09, 2009 | 2006 Dodge Ram 1500
Feb 27, 2009 | 1999 Lincoln Town Car
547 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: