2002 f150 running poorly
#1
03-29-2014, 08:17 PM
2002 f150 running poorly
My sons truck,4.2, started running bad and check engine light came on. Codes
P0316,0174,0302,0305,0306 showed up. We have changed the air filter, fuel filter, plugs, plug wires, and coil pack. We also cleaned the throttle body and mass air flow, also checked for vacuum leaks(found none). I hade the battery disconnected and all the codes cleared. I've driven the truck appx 15 miles and the only code to show up so far is p0174. My son says it is running a little better than before but it is still running terrible. It did seem to run better the longer I drove it. I'm sure it is just a matter of time before more codes show up. Any help would be appreciated.
P0316,0174,0302,0305,0306 showed up. We have changed the air filter, fuel filter, plugs, plug wires, and coil pack. We also cleaned the throttle body and mass air flow, also checked for vacuum leaks(found none). I hade the battery disconnected and all the codes cleared. I've driven the truck appx 15 miles and the only code to show up so far is p0174. My son says it is running a little better than before but it is still running terrible. It did seem to run better the longer I drove it. I'm sure it is just a matter of time before more codes show up. Any help would be appreciated.
#2
03-30-2014, 04:50 AM
There could be a poor connection with the crank sensor and related wiring.
When you replaced the coil pack , hope you marked the wires before removing them because the positions don't follow a perfect sequence. Make sure they are on the correct coil tower.
PO174 indicates a lean condition on bank 2 ,drivers side of engine. You might want to check the PCV valve and hose for possible crack or hole in hose connection.
Last but not least if the engine idles rough , but smooths out with an increase in RPM confirms a vacuum leak on driver's side of engine. That could be leaking intake manifold gaskets /grommets and would require replacement of both.
When you replaced the coil pack , hope you marked the wires before removing them because the positions don't follow a perfect sequence. Make sure they are on the correct coil tower.
PO174 indicates a lean condition on bank 2 ,drivers side of engine. You might want to check the PCV valve and hose for possible crack or hole in hose connection.
Last but not least if the engine idles rough , but smooths out with an increase in RPM confirms a vacuum leak on driver's side of engine. That could be leaking intake manifold gaskets /grommets and would require replacement of both.
#3
03-30-2014, 01:40 PM
Plug wires are on correctly. PCV valve working properly. Checked again for vacuum leaks, found none. Not sure how to check for leaks at manifold gasket. Replaced crankshaft sensor, no difference. Son said when he parked the truck it was running fine, next morning it was running terrible if that makes any difference.
#4
03-30-2014, 02:36 PM
We're just speculating here, but as parts cool they contract and gaps open allowing air to pass. When heated expansion closes the gaps and air may be restricted or blocked completely. That could possibly be the reason it runs somewhat better when warmed up.
If this is what is happening could very well be gasket problem. There are tests that can be done to confirm something like this , but you need a scan tool to measure the fuel trims etc., to see if this is what is taking place.
If this is what is happening could very well be gasket problem. There are tests that can be done to confirm something like this , but you need a scan tool to measure the fuel trims etc., to see if this is what is taking place.
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