# 1995 HB Compression



## stephank (Nov 15, 2005)

Guys, 

I have a 1995 HB 4x4 with a 2.4L 4 cylinder engine. What should the compression be in each cylinder? It will not pass emissions due to high hydrocarbons at idle speed. All other emissions pass. I did a compression test and they are all pretty equal. What else could be causing the hydro carbon issue at idle speed? It actually seems to run pretty good for a 4 banger, doesn't really hesitate or anything.

Any suggestions would be greatly appreciated!!!

Stephan


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## smj999smj (Jan 1, 2006)

Start engine and run until engine reaches operating temperature.
Turn ignition switch off.
Release fuel pressure. Refer to Technician Safety Information for fuel system pressure release procedure.
Remove all spark plugs.
Disconnect distributor coil cable.
Attach a compression tester to cylinder No. 1.
Depress accelerator pedal fully to keep throttle valve wide open.
Crank engine and record highest gauge indication.
Repeat measurement on each cylinder.
* Standard compression is 192 psi, minimum pressure is 142 psi and compression difference limit between cylinders is 14 psi*.
If compression in one or more cylinders is low, pour a small amount of engine oil into cylinders through spark plug holes, then retest compression.
If adding oil helps compression, then piston rings may be at fault. If adding oil does not help compression, then valves may be at fault.
If compression stays low in two cylinders that are next to each other, then cylinder head gasket may be leaking or both cylinders have valve component damage.
Repair as necessary.


You might find this info helpful:


What causes high HC. What causes high Hydrocarbon - SmogTips.com. Failed HC Emissions. Why did my car fail the emission test for high HC emissions. What is HC. My vehicle failed the emission test for high Hydrocarbons. Why my car produced high HC. Hi


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## CMax03 (Jan 17, 2009)

stephank said:


> Guys,
> 
> I have a 1995 HB 4x4 with a 2.4L 4 cylinder engine. What should the compression be in each cylinder? It will not pass emissions due to high hydrocarbons at idle speed. All other emissions pass. I did a compression test and they are all pretty equal. What else could be causing the hydro carbon issue at idle speed? It actually seems to run pretty good for a 4 banger, doesn't really hesitate or anything.
> 
> ...


My suggestion to you would be to change your oil and filter warm the vehicle up and immediately go get your emmisions done...You shou=ld pass if everything is in good working order! I have a cam, headers, ported intake and head and I never failed using that method for over 10 yrs!


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