M42 won't start

[Jordan]

The cams line up by placing a straight edge across the blocks all the way at the back of the cams so that there is no gap on the straight edge, best judgement is best, do not need to be perfect.

Both edges pointing up and being level should have 2 dimples in them.

[Funkmasta]

The timing is correct (at least close enough).

We tested the compression guage AND the leak down tester on the good M42 AFTER the failed readings on Ken's motor.

Cylinder 2 had the highest compression @ 120. The other 3 cylinders ranged from 60-80.

[Funkmasta]

Both edges pointing up and being level should have 2 dimples in them.

With cyl 1 at TDC, both arrows on the cams were pointed straight up, and both cam lobes for cyl 1 were pointed at their 45 degree angle toward eachother like they should be.

Makes no sense to me.

Ken did mention that his last couple tanks his mpg had gone down considerably.
I guess when they go, they go. ?

[Hick]

Well, the only thing i can think of that would of caused this is that the car wouldnt start from a problem but the compression issue is as a result of trying to fix the motor.

[Funkmasta]

Well, the only thing i can think of that would of caused this is that the car wouldnt start from a problem but the compression issue is as a result of trying to fix the motor.

Nope.

[Jordan]

120 is very low, 60-80 is just plain insufficient compression. When I tested my M42 last month it was:

Cylinder 1: 201psi
Cylinder 2: 195psi
Cylinder 3: 209psi
Cylinder 4: 195psi

Which I'd suspect to be pretty normal for a good running M42.

As for Ken's motor... its got a cracked/warped head or a bad head gasket. Bent valves are unlikely as I'm sure he would have noticed the noise.

[FredK]

I comp tested an M42 with 200K+ that sounded OK while running, and it comped out at 130, 90, 130, 90 psi.

[Hick]

Nope.

What do you mean 'Nope'

If he sits there and cranks on it for a day and theres no spark the fuel will wash the cylinder walls of oil which can damage the rings and walls. Unlikely, but possible.

GL fixing it.

[KenC]

I comp tested an M42 with 200K+ that sounded OK while running, and it comped out at 130, 90, 130, 90 psi.

All four tested at 190-210 about a month ago.

[Van Westervelt]

This blows. As of Sat, my birthday. I am now in the same boat as Ken with my m42. Beginning the trouble shooting phase now. :(

[KenC]

This blows. As of Sat, my birthday. I am now in the same boat as Ken with my m42. Beginning the trouble shooting phase now. :(

Totally forgot to call you back man. If you have any more questions about it feel free to give me a ring.

[mattdk318i]

not to thread jack but i have a bunch of M42 parts including good head and block. Just in case

[Van Westervelt]

Totally forgot to call you back man. If you have any more questions about it feel free to give me a ring.

m42 fuel pump builds pressure when you turn the key to on just like m20's right? so I should hear it...

[KenC]

m42 fuel pump builds pressure when you turn the key to on just like m20's right? so I should hear it...

Yeah, you can hear it when it's cranking.

[Van Westervelt]

Yeah, you can hear it when it's cranking.

Only when cranking? I can hear my m20 pump when i turn the key to on... ?