Low Idle/ Engine Dies After Changing Spark Plugs
05-13-2014, 04:54 PM
#1
Junior Member
Thread Starter
Low Idle/ Engine Dies After Changing Spark Plugs
I have a 2004 F150 Lariat 5.4L V8. Now about two weeks ago I did my spark plugs at 99,800k and luckily nothing broke. I ran Lucas Deep Clean in my last two tanks of gas to help with the carbon deposits. I didn't have to spray any carb cleaner in the spark plug wells or anything, They all came out fairly easy. When I put the new spark plugs I made sure to put anti-seize grease on the shield of the spark plug and to put some dielectric grease on the boots as well. 
The next day I started to notice my truck idling very low when in park, at a stop (in drive), and when I drive in reverse 
but I don't have any problems when I drive in general whether its on the street or highway. I've also notice that there is slightly more of a struggle for it to accelerate because I get higher rpms but nothing exaggerated. Sometimes I will have the engine die but it will start up again with no problem. I will get this oil/fuel smells from my vents when I have them on whenever I start it up again after it dies.
Now I know that nothing is wrong with my oil pressure because when the engine dies and the key is on it will obviously go off and I also know that because of having to disconnect the computer and reconnect it, it has to relearn the drive cycle all over again. I made sure all my connections were secure and double checked anything that I took off was in the right place. I've been driving it and yet I still have the problem?
The next day I started to notice my truck idling very low when in park, at a stop (in drive), and when I drive in reverse but I don't have any problems when I drive in general whether its on the street or highway. I've also notice that there is slightly more of a struggle for it to accelerate because I get higher rpms but nothing exaggerated. Sometimes I will have the engine die but it will start up again with no problem. I will get this oil/fuel smells from my vents when I have them on whenever I start it up again after it dies. Now I know that nothing is wrong with my oil pressure because when the engine dies and the key is on it will obviously go off and I also know that because of having to disconnect the computer and reconnect it, it has to relearn the drive cycle all over again. I made sure all my connections were secure and double checked anything that I took off was in the right place. I've been driving it and yet I still have the problem?
05-13-2014, 06:02 PM
#3
I have a 2004 F150 Lariat 5.4L V8. Now about two weeks ago I did my spark plugs at 99,800k and luckily nothing broke. I ran Lucas Deep Clean in my last two tanks of gas to help with the carbon deposits. I didn't have to spray any carb cleaner in the spark plug wells or anything, They all came out fairly easy. When I put the new spark plugs I made sure to put anti-seize grease on the shield of the spark plug and to put some dielectric grease on the boots as well. The next day I started to notice my truck idling very low when in park, at a stop (in drive), and when I drive in reverse but I don't have any problems when I drive in general whether its on the street or highway. I've also notice that there is slightly more of a struggle for it to accelerate because I get higher rpms but nothing exaggerated. Sometimes I will have the engine die but it will start up again with no problem. I will get this oil/fuel smells from my vents when I have them on whenever I start it up again after it dies. Now I know that nothing is wrong with my oil pressure because when the engine dies and the key is on it will obviously go off and I also know that because of having to disconnect the computer and reconnect it, it has to relearn the drive cycle all over again. I made sure all my connections were secure and double checked anything that I took off was in the right place. I've been driving it and yet I still have the problem?
The next day I started to notice my truck idling very low when in park, at a stop (in drive), and when I drive in reverse but I don't have any problems when I drive in general whether its on the street or highway. I've also notice that there is slightly more of a struggle for it to accelerate because I get higher rpms but nothing exaggerated. Sometimes I will have the engine die but it will start up again with no problem. I will get this oil/fuel smells from my vents when I have them on whenever I start it up again after it dies. Now I know that nothing is wrong with my oil pressure because when the engine dies and the key is on it will obviously go off and I also know that because of having to disconnect the computer and reconnect it, it has to relearn the drive cycle all over again. I made sure all my connections were secure and double checked anything that I took off was in the right place. I've been driving it and yet I still have the problem?^^^ A fuel smell usually means either one or more loose plugs or misfires, or an incorrectly seated fuel rail ( if you removed it to R&R the plugs ).
Check all plugs for correct torque.
Did you apply the dielectric grease like this: https://www.f150forum.com/f38/recomm...2/#post3272459
Get any pending codes pulled, if any (no CEL).
BTW - what plugs did you use?
good luck
MGD
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Tony_1993 (05-14-2014)
05-14-2014, 10:57 AM
#4
Junior Member
Thread Starter
Hi MGD,
I used the recommended Motorcraft spark plugs from the local Autozone store and I didn't gauge how much torque I put into the plugs, I just tightened them till they where snug. So what exactly would the correct torque be if you happen to know? If not could I find this in the manual? As for the dielectric grease application I didn't do it the way stated on the link, all I did was wipe off the outside and opening of the boot and then applied the grease. So if anything I will probably torque the spark plugs to the right specs and regrease the coils the way stated in the link this weekend and see what happens. I'm not getting any pending codes, the only code I'm getting is P1000 which is that the OBD-II monitor testing is not complete. I know that codes occurs because I disconnected the computer but other than that I'm not getting anything else. Also I was going to remove the fuel rail but I never fully removed all the bolts I just removed one and then put it back. So do you think that is enough to improperly seat it or even ruin the seal?
I used the recommended Motorcraft spark plugs from the local Autozone store and I didn't gauge how much torque I put into the plugs, I just tightened them till they where snug. So what exactly would the correct torque be if you happen to know? If not could I find this in the manual? As for the dielectric grease application I didn't do it the way stated on the link, all I did was wipe off the outside and opening of the boot and then applied the grease. So if anything I will probably torque the spark plugs to the right specs and regrease the coils the way stated in the link this weekend and see what happens. I'm not getting any pending codes, the only code I'm getting is P1000 which is that the OBD-II monitor testing is not complete. I know that codes occurs because I disconnected the computer but other than that I'm not getting anything else. Also I was going to remove the fuel rail but I never fully removed all the bolts I just removed one and then put it back. So do you think that is enough to improperly seat it or even ruin the seal?
05-14-2014, 06:34 PM
#5
Hi MGD,
I used the recommended Motorcraft spark plugs from the local Autozone store and I didn't gauge how much torque I put into the plugs, I just tightened them till they where snug. So what exactly would the correct torque be if you happen to know? If not could I find this in the manual? As for the dielectric grease application I didn't do it the way stated on the link, all I did was wipe off the outside and opening of the boot and then applied the grease. So if anything I will probably torque the spark plugs to the right specs and regrease the coils the way stated in the link this weekend and see what happens. I'm not getting any pending codes, the only code I'm getting is P1000 which is that the OBD-II monitor testing is not complete. I know that codes occurs because I disconnected the computer but other than that I'm not getting anything else. Also I was going to remove the fuel rail but I never fully removed all the bolts I just removed one and then put it back. So do you think that is enough to improperly seat it or even ruin the seal?
I used the recommended Motorcraft spark plugs from the local Autozone store and I didn't gauge how much torque I put into the plugs, I just tightened them till they where snug. So what exactly would the correct torque be if you happen to know? If not could I find this in the manual? As for the dielectric grease application I didn't do it the way stated on the link, all I did was wipe off the outside and opening of the boot and then applied the grease. So if anything I will probably torque the spark plugs to the right specs and regrease the coils the way stated in the link this weekend and see what happens. I'm not getting any pending codes, the only code I'm getting is P1000 which is that the OBD-II monitor testing is not complete. I know that codes occurs because I disconnected the computer but other than that I'm not getting anything else. Also I was going to remove the fuel rail but I never fully removed all the bolts I just removed one and then put it back. So do you think that is enough to improperly seat it or even ruin the seal?
Pending misfire codes require a scanner capable of extracting them - not all (especially the basic ones) can do that.
Sometimes the grease can interfere with reliable firing, which is why the procedures exist.
Plug torque is 25 ft-lbs DRY.
Can't really say about yer fuel rail - if the rail was partially lifted, it could have potentially displaced an o-ring.
I'd start confirming no misfire codes are pending (which will point right to the offending cylinder(s)). If no joy, then check all the plugs for tightness and redo the grease as best you can.
Best of luck
MGD