My compression test results

[fyton2v]

For my new to me '78 FJ40 with a 2F. Bought a cheap Napa compression tester.

From front to back:
cyl 1: 145 psi
cyl 2: 122 to 125 psi (wet: max is 135)
cyl 3: 145 psi
cyl 4: 143 psi
cyl 5: 145 psi
cyl 6: 144 psi

So 2 is pretty low. The rest seem good. Last valve job on this car was probably quite a while ago. What could be causing the #2 issue?

On a side note: I can smell exhaust in the cab while driving. Possible leak in the manifold? The exhaust pipe is a little rusty, but I can't see any holes.

Thanks guys.

 

[fsusteve]

Those numbers are decent enough, #2 could be a burnt valve or a valve that needs adjusting. If you have exhaust in the cab, you have a leak somewhere, possibly the donut at the manifold/exhaust connection.

 

[CruisinGA]

probably an exhaust leak in one or more of 3 places, where the manifold meets the head, where the pipe meets the manifold, the gasket between the intake and exhaust manifold.

Check manifold gasket visually and tighten studs if gasket is not bad. If it is bad I would consider installing two new gaskets. (toyota OEM only).

Check donut gasket where manifold meets downpipe. Replace/tighten.

It is normally obvious if the leak is between the two manifolds. (blackening of the manifolds). This is the biggest P.I.T.A. to replace, requires removal of the carb/manifold assembly and then dissasembly involving many studs tend to rust and strip due to high heat.

have fun, all three were bad on my truck when I got it. I had the entire assembly out twice in a week before I had all the leaks fixed. Haven't had to touch it in a year and a half.

 

[petescoffee]

If you have a little more money or can borrow one, do a leak down test. Or check for an exhaust leak, Start the motor and spray some wd40 around the exhaust manifold and look for signs of leaking.

 

[fyton2v]

What's a leak down test?

Hmmmm?

 

[mallred]

Wd 40 ???? Thats new to me, what do you look for ? A FLAME ?????

 

[fyton2v]

Don't have any wd40

Do have some gasoline though. I'll just pour some of that around the manifold and look for bubbles.