Truck Misses At Low RPM

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Old 02-16-2008, 03:40 PM
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Truck Misses At Low RPM

I have a 99 ford f150 and when it is in low rpm it jumps and misses. When i put in nutruel it is fine, but when it attempts to go at a slope it misses. I had the intake gasket changed and the spark plugs. When we opened it up it had water/oil where the spark plugs were. We think it could be a cracked head or head gaskets.. i just needed some f150 pros opinions before we pulled the motor..
 
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Old 02-16-2008, 04:26 PM
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Did you make sure all the plugs are good? I know there new but so were mine and one of them failed(dont buy champion) Check the injectors to see if there working. Put a long flat screwdriver on the end and put your ear on the handle to see if its clicking. Also one of your coils could be shot. switch the coil around or unplug it see if the problem gets worse or stays the same. that will narrow down the cylinder
 
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Old 02-16-2008, 04:40 PM
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Which engine, please? Advice is going to be totally different depending whether it's a 4.2, 4.6, or 5.4.
 
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Old 02-16-2008, 05:12 PM
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haha sorry about that. its the 4.6 triton v8. and to the spark plugs may be bad,it did it even before we had the new ones in it.. and these are good plugs also.
 

Last edited by xworshipx; 02-16-2008 at 05:25 PM.
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Old 02-16-2008, 06:03 PM
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Is your CEL on? any codes? Could be a bad coil. How much moisture? does it smell like antifreeze? sniff the exhaust... no antifreeze smell probably not a leak. is there evidence of water on the dipstick?
 
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Old 02-17-2008, 02:18 PM
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1. What plugs did you put in?
2. You may have bad plug wires and/or coil pack/packs.
3. Did you use any dielectric grease?
4. Getting water/oil into the plug wells is common on these engines - from external leakage. It's way too early to start blaming head gaskets or cracked heads.
 
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Old 02-18-2008, 08:57 AM
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1. i put bosche platinum
2. ill try to put some wires and they have 2 coils on them right?
3. No...
4. i got it worked on at Tn Tech, a student in training type thing haha.

To the post above it.. idk.. haha.. i dont have it.. its at tn tech so i cant really get it and observe it.. im going to take it else where if i replace some stuff and it doesnt fix it.

Also, they said that they couldnt keep compression in the #4 cylinder when they did a compression test. idk if that helps any or not..
 

Last edited by xworshipx; 02-18-2008 at 09:33 AM.
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Old 02-18-2008, 02:46 PM
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1. The worst plugs you can buy for your engine.
2. 2 coil packs - each feed 4 cylinders.
3. You need to whenever changing plugs and/or wires and/or coil packs.

If the compression is bad in #4, you have a mechanical issue - it probably is time for a teardown and rebuild.
 
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Old 02-20-2008, 09:19 AM
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i took it off too a certified mechanic and they told me the same thing you told me glc, i had a honda before his, little crx and they always told me that bosche was a good brand.. guess they was just talking about for hondas haha. they r going to replace the wires and plugs and go on from there. i could of done this myself and saved ALOT of money but you kno how it is.. lol..
 



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