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  #1  
Old 03-07-2013, 01:51 PM
Learning to use the forums
 
Join Date: Mar 2013
Posts: 6
Default Compression test

Hey all this is my first time asking a question on this forum so hopefully I'm putting this in the right section...

About a month ago I had a problem with my truck, the check engine light came on and I was getting crazy backfires. The backfires got worse the more I drove (had to get it to a shop that I could work on it in). I plugged the truck into my buddies diagnostics computer and found I was having a cylinder 4 misfire. So I replaced all the plugs and plug wires, but the problem persisted so I put a new distributor cap in and the truck ran fine.
(I did the electrical because it sounded like unburnt fuel was making it into the exhaust system)

Most of the plugs had black crud all the way up the threads, and most all of them smelled like fuel.
My buddy suggested I run a compression test to see if the head gasket maybe needs to be replaced.

So what is a good Psi reading for one of these trucks?
Thanks
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white 1998 Ranger, 4.0L V6, automatic transmission,
4X4 on the fly, stock XLT truck.
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  #2  
Old 03-07-2013, 01:56 PM
Ford Motor Co
 
Join Date: Jan 2013
Posts: 171
Default Re: Compression test

I believe the numbers should be equal and above 100...
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2006 Ford Ranger XL Std Cab 2.3L 5Spd 4x2
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  #3  
Old 03-07-2013, 04:25 PM
Ford Rangers
 
Join Date: Dec 2010
Posts: 204
Default Re: Compression test

I looked through my ranger service manual and didn't see a PSI rating for it, 100+ is good though.
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1998 Ranger Supercab 4.0L, Medium Metallic XLT, auto, painted valve covers (10 HP), 30x9.5/15.

2008 Mustang GT, 5spd, Ford Racing Hot Rod cams, Roush R2300 supercharger, Eibach suspension, BBK shorty headers, GT500 TB, BBK Hi flow catted X, Flowmaster cat-back exhaust, and a GT500 fuel pump setup.
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