A14, no compression #2 cylinder

[Conley]

Hey guys!

Trouble in B210 land. Engine is having issues, turns out no compression is showing on cylinder two.

Car is a 75 B210, stock A14 and 4 speed.

 

Yesterday I was returning home, had just been doing about 70-75 on the freeway, and as soon as I pulled onto my street, the car started sounding terrible. I killed it and coasted into my driveway, assumed I had killed the alternator belt. I popped the hood, belt is good. Checked the oil, level was a little high, but fresh oil from a change last week.

So, I turned the key, engine will start, but doesn't hold an idle, slowly dies out. Seems like not enough fuel. There's an inline filter near the gas tank, and it was filthy so I put in a fresh one, old one was possibly clogged partially. I also pulled all the plugs, some oil on the threads of 1 and 2 but not too much. Plug ends look good. I put them back in, take off the air cleaner, and verify that the carb is squirting fuel when you pull the throttle.

At this point, I tried to start the car, and it ran rough for a second and then cleared up, and ran normally. I drove it to the parts store for some Seafoam, and ran some through the carburetor slowly, added a little to the tank too.

It ran great. So, I considered it fixed.

Then, I tried to drive it somewhere later that night and it sounded like shit again and wouldn't hold an idle.

So, today, I fiddled with the fuel filter and line again, its getting fuel, and I pulled the plugs, still look okay. Tried to make sure they were all getting spark but the old timing light I have would not light up.

Then I busted out a compression tester my uncle had left at my house. 1, 3 and 4 are showing over 140 psi, but cylinder 2 shows absolutely nothing. Nothing at all.

I figure if its a busted piston ring, it would still show some pressure. I added a teaspoon of oil and as I thought, it didn't do anything.

Could this be caused by a stuck open valve? I was searching through old posts for answers, and learned that the valve seat could fall out and get stuck on an L motor, so I bet that's a possible for this A motor. It also said the head has to be pulled unfortunately.

Could be a catalyst to get my L20B and 5 speed running and into the car though!

 

Anyone have any suggestions/comments?

Thank you guys for your help!

[Draker]

Sounds like a valve issue to me!

[datzenmike]

Turn the engine so that both intake and exhaust valves are closed on the #2 cylinder. Try to wiggle both rocker arms. There should always be just a little valve clearance that will allow this. If one is tight the valve may not be closing. It may run normally when warming up and then not. Probably the exhaust as it runs the hottest. The valves are cooled by heat transfer to the valve seat during the time the valve is closed and making contact.

[Conley]

Thanks for the reply. I had the valve cover off, the two rockers for #2 didn't wiggle but the others did. Thought that was odd, but I didnt know what i was looking for, it didn't even occur to me to try and rotate the engine by hand. I'll try that out and report back.

[datzenmike]

If they are tight set the proper clearance. I don't know off hand what that is.

[datsunfreak]

If they are tight set the proper clearance. I don't know off hand what that is.

 

.012 

 

But always check the service manual.   B)

 

I would say back them all the way off so the valves stay closed then compression test again. If good, then rockers. If bad, then valve or piston problems (time to open it up). 

[Conley]

Well, its been a crazy week. My assistant manager at work walked out on shift and it's been hell.

I finally just rotated the engine to valves closed on #2 and they did wiggle, one only a little, one nearly an 1/8"

I'm off to buy some feeler gauges to set the proper clearance!