Help needed!! Truck runs awful after spark plug change
07-09-2012, 01:45 PM
#1
Help needed!! Truck runs awful after spark plug change
I had a really bad vibration, lack of power/acceleration at highway speeds the other day. Check engine light was blinking then goes solid. I ran down to autozone so I could get the code read. Codes that came up were cyl 6 misfire and lean fuel mixture on left bank.
SO today I changed the plugs with MC 515, put a bottle of Lucas octane boost into about half a tank of gas. Took it around the block to mix in the octane boost and warm the engine a little. Broke 5 plugs which I was able to get out with the Lisle tool. I anti-seized the plugs, dielectric grease on the COP, computer back on the firewall, all 3 plugs back into the computer and reinstalled the battery.
I took it for a test drive and seemed to be running smooth at first. Got on the freeway and got it up to speed everything seems fine. Back of the freeway and it doesn't want to idle at the stop light. RPMs drop down to around 300, lags really bad from a stop until RPMs get to around 2k. It still feels like its misfiring/shaking around 40mph on a slight incline at around 1100 RPM. I stopped at the store, come back out fire it up and the check engine light is back on. Same misfire/low idle problems again. Pulled into a parking lot and came to stop, truck stalls, restart, stalls. Limped it home and threw it in park and it will at least idle without stallings.
Some help with this would be really great. Thanks guys
SO today I changed the plugs with MC 515, put a bottle of Lucas octane boost into about half a tank of gas. Took it around the block to mix in the octane boost and warm the engine a little. Broke 5 plugs which I was able to get out with the Lisle tool. I anti-seized the plugs, dielectric grease on the COP, computer back on the firewall, all 3 plugs back into the computer and reinstalled the battery.
I took it for a test drive and seemed to be running smooth at first. Got on the freeway and got it up to speed everything seems fine. Back of the freeway and it doesn't want to idle at the stop light. RPMs drop down to around 300, lags really bad from a stop until RPMs get to around 2k. It still feels like its misfiring/shaking around 40mph on a slight incline at around 1100 RPM. I stopped at the store, come back out fire it up and the check engine light is back on. Same misfire/low idle problems again. Pulled into a parking lot and came to stop, truck stalls, restart, stalls. Limped it home and threw it in park and it will at least idle without stallings.
Some help with this would be really great. Thanks guys
07-09-2012, 02:13 PM
#3
I numbered all the COP and replaced them to the proper cyl. Is it possible the it doesnt seat properly on the plug? They all seemed to slip right in. Someone also suggested a vacum leak but that would be tough for me to track down.
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07-09-2012, 02:44 PM
#8
Senior Member
First thing's first, pull off the COPs and retorque your plugs.
You don't want to know how much I spent figuring that one out when it happened to me.
You don't want to know how much I spent figuring that one out when it happened to me.