well guys remember my engine problem i stated in another thread...here are the compression results.

162, 165, 168, 165

boeturbolancer.....seems good??

that seems quite normal to me. so i have no clue what the damn problem is now. i'm guessing its my fuel system that is making my motor seem likes it turns off for a second or two then turn back on.

here is the link to the thread where i explained it better...
https://www.evolutionm.net/forums/sh...threadid=14593

 

That is not good. Did you heat up the motor then dry crank it a few times before testing? That is basically the procedure. Engine should be warm and cylinders wet... meaning oiled but engine no fire in cylinder which leaves it wet. Then the compression check should be minimum of 170! You should be around 200-210! You have some problems if you did as i stated above and got those numbers. You may have scorched you top rings with that extremely lean air/fuel ratio and they have been degrading ever since. Or, if you cranked up the boost, you may have started to compress the top crown/ring land. I would go no further on the motor, driving wise, till you get this investigated further. Talk with Rob and verify my answer. I'm going by the factory book and my car. I've got 208-210-215-212. Good luck and let me know any further info.

 

ok....this is odd....like everything else that happens in my life...

compression test day 2:

190, 190, 180, 160

on the 160 cylindar i kept getting like 0 then 30 then 0 again because i don't think i got the thing in tight enough...i don't have that long extension tool to tighten it so i jus twist the rubber hose has much as i can so it might be more then 160

 

Seems weird to me... you should get the tool and check it for sure. No second chances in this game. 160 not good at all. Get the tool, know for sure, then post and we'll see whats up

 

Isn't this vehicle running the RPW Decompression head gasket. If it is then that compression is about right and the fact that it is quite consistent across the board shouldn't be yuor cause of stalling and then starting again.

Check fuel system as you could be running out of fuel pressure at say max psi boost etc.

David Thomas
www.rpw.com.au

 

No, I'm still at stock compression. but i'm taking my car to get looked at professionally. i might need that decompression head gasket Mitsiman if my engine needs to be rebuilt.

 

You need two people to help you.

You have to stomp 100% on the throttle, cranking 4-6 turnovers. At 88% throttle, you'll get different results.

You should get at most 220 and at lowest 210's w/o decompression gasket (a difference of 4 between one value to another at most). If you over crank it, there is a temp release valve that the gauge shoots out a bit like an indy car pop-off value. You'll hear a metallic pop, meaning a redo.

If it's still not satisfactory, you need to pull the cyl head off.

If you romp on the throttle a lot in daily driving, you might have bent a rod or something.

If not, chk the next problem. Visual inspection for nicks on the piston head.

Then, with your fingers, move the piston within its cyl walls. If it has play, the connecting pins on the conrods to the piston are broken. The piston should have absolutely no play from side to side.

This is all that I have witnessed or experienced.

 

i was not stepping in the throttle when i was cranking over the motor...this might be why the numbers are low....i'll retest...

 

Stepping on throttle will not do anything good... actually bad as it will enter fuel into your cylinder that will not be burnt only compressed then expelled. In all actuality you should disconnect fuel inj. system to not allow fuel flow and then crank over. If you want i can scan a copy of procedure right out of factory book for you. That should end all this throttle bs.

 

well when you open the throttle you actually increase the ability for the engine it get more air to compress giving a more solid compression result. if you completely closed off the throttle body the engine would not get any air to compress which would make no compression correct?

 

Yes you must have the throttle position at 100% when cranking the engine for the compression test. Of course you disconnect both the coil pack and pull the fuse for the fuel before doing it.

Also if I remember correctly, a wet test is where you put a small amount of oil in the cylinder when re-testing. This oil coates the sides of the pistons. If you get higher compression than during the dry test, it shows that your problem is from air leaking past the piston.

 

"Also if I remember correctly, a wet test is where you put a small amount of oil in the cylinder when re-testing. This oil coates the sides of the pistons. If you get higher compression than during the dry test, it shows that your problem is from air leaking past the piston. "

I thought you only do a wet test if you want a "second opinion" on the first test. Just to back up the proof that something is blown.

Otherwise, TSU is correct. It should be on the instruction manual on the CR tester package or something.

BTW: I think it's a tablespoon of oil. For me, I just take off all the electrical stuff and crank the motor up. After each test, I have 1 less plug on the motor.

BTW II: If you don't disconnect the plug wires and coil packs, the motor will fire up. I have started my motor with just 3 plugs in the motor. Misfire like hell.

In the past, I have a buddy who fired up his chevette with 2 spark plugs in the motor. A couple months later, the engine died because of oil starvation problems from ill maintanence.

 

well i also heard your supposed to take all the plugs out and put the compression tester in one then crank the motor over? (thats that my compression tester directions say) maybe to make the engine spin easier and take strain off the battery? is this also another way to do it. then there would be no chance of ignition.

 

First let me appologize for the mistake about throttle. My bad there... just brain farted on that one. Now to clear it all up here is the Mitsubishi Lancer tech pub for compression check. Enjoy!

 

boe....any way to get a better scan of that...i can't seem to make out what it says in photoshop