Engine from the netherworld

[mudman]

I am trying to get an EA71 engine to run well. I have replaced alot on this engine, except for pulling the heads and rebuilding the entire thing.

 

The last time that I cranked it over, the feeze plugs blew out and the whole engine was filled with water. I replaced the plugs, flushed the engine, and checked compression.

 

Compression is fine, and the freeze plugs don't leak. I put a new carb on it, removed all emmissions, and plugged all vac lines.

 

I fired it up, and I thought that it was running fine. I have the engine on a skid right now, so I'm running dual exhaust. Well, come to find out, only one pipe gets hot, and the other is ice cold. I had fuel coming out of the exhaust on the cold side, so, I figure that I have fuel.

 

I replaced the rotor, and cap. I set timing to 8 degrees before TDC. I checked the pick up coil and it read good also. Oh, and new spak plugs of course.

 

I checked the spark plugs and they ARE firing on the bad side (just laid it on the intake maniflod, shocked me pretty good too). I had fuel coming from the exhaust, so I have fuel. Fuel + Fire = Vroom vroom Right?

 

Funny thing is, once it is hot, the one side gives a good POP every few seconds. The engine really runs good on only 2 cylinders, so I really can't wait to get 4 up and going.

 

The only other thing that I can think of is the ignitor. But would that cause the engine to only "work" on one side? If it could possibly be the ignitor, then I'll probably replace the ignition system with a new distributor that has points, and a new ignition coil.

 

If anyone has any other ideas, please, I'm all ears.

[bobjr94]

Something else, maybe you have an intake leak on that side. Or if the motor did have water in it, it may have bent a connecting rod causing, split a piston or gasket giving one or more low cylinders. What was the compression #s you were getting.

[subaruguru]

i think you mihgt have the wires wrong i had an engine once that was only fring on one side turns out they where fireing on both but one side was firing after the fule had dumped out of the cylinder

[mudman]

Compression was at about 170 to 175. I don't think that something like that could have happened with good compression readings, Right?

 

All lines were plugged, so I am running the engine "dirty". EGR is plugged, PCV is plugged, all intakes are plugged. The only thing hooked up is vacuum advance.

 

There are also some stainless tubes that run from the head (next to the spark plug) to a box. There they go into one stainless tube and then to atmosphere. I plugged this also believing that is is just another part of the emissions system. I have the valve covers venting to atmosphere.

 

I dont think that the wires are crossed. They are hooked up just like the book says. Anyway, I reversed the wires on that one side and nothing happened. I think that I might go home and just shoot the engine.

[idosubaru]

if you have compression, spark and fuel then it seems to me that the timing has to be off, particularly considering it must be both cylinders that aren't firing right since the exhaust isnt' getting hot? and by timing i mean it in the general sense not just (8 degrees, etc). the wires being crossed artificially screws up timing...etc. but i know nothing about these engines so i can't offer anything specific to look for.

 

I think that I might go home and just shoot the engine.

please have a video camera for this one!

[mudman]

Most people think that it is timing. I can't understand how timing would be off on one side and not the other. Could it be that little $300 dollar ignition module? Could it be that the lobes on one side of the cam are screwed up? Could it be that the fuel is only going to one side of the engine?

 

I guess that all of these are possible, but they don't really make alot of sense. Anybody want to help me turn it upside down to shake the gremlin out of it?

 

What could make timing off on only one side besides mixing up the spark plug wires?

What could make fuel go to only one side besides a vac leak?

If compression is good, then all pistons, rods, and valves should be OK, right?

[joostvdw]

It's not how high the compression is (of course, till a certain level) but it's more the difference between the cilinders, a big difference means trouble, sounds like you got that covered though, but I wanted to mention it.

 

Where did you get the spark plug firing order from? Some manuals give erroneous data, you should search here on the board for the correct firing order. Also, and I hate to say it, fully re-do your ignition timing, there is proper write-up on how to do this floating around on the board so the search is your friend.

 

Oh and it's not the ignition module, if that's broken, no cilinder will fire. Make sure though the coil and the igniter are grounding properly through the bracket.

[mudman]

OK. I've been playing all evening debugging things by the process of elemination. Here's what I found out.

 

The engine was running on only yhe 1-3 side. If I take off the 1-3 side and just hook up the 2-4 side, and give it some gas, the engine will run. I can even let it down to idle with only yhe 2-4 side hooked up. So, Therefore it isn't pistons, valves, rods, etc. The compression test also proves this.

 

Now, as long as I give it some gas(and not alot really), and hook up both sides, both sides run!!!!!

 

A few seconds after I hook up both sides, and let it to idle, then only the 1-3 side works.

 

I don't think that this engine was designed to idle on only one side, was it?

 

Bsides getting a new distributer, what can I do? New coil? NGK plugs? I really don't get what could be wrong if each side will work seperately, but not together.

[jeffast]

I would change out the cap and rotor, and see if that made a difference

[john in KY]

Runs at rpms above idle but will not idle? You have an intake manifold vacuum leak somewhere.

[Reveeen]

The engine was running on only yhe 1-3 side. If I take off the 1-3 side and just hook up the 2-4 side, and give it some gas, the engine will run. I can even let it down to idle with only yhe 2-4 side hooked up. So, Therefore it isn't pistons, valves, rods, etc. The compression test also proves this.

 

 

While I don't know a whole lot about this specific engine, if it was a V-8, you describe EXACTLY the old time test for a large vacuum leak. I would *think* the same thing applies here.