Hi everyone, new to this forum. I havea 1991 MAzda B2600I pick up truck. Was driving down the road the other and it dies. I get it home and try to start it - turns over fine but really fast. sounds like no compression, remove the valve cover everything is turning fine, timing chain intact. Put a compresssion tester on it-#1 cyl-1-2psi, #2-5 psi, #3, 10 psi, #4 30psi. I dont know anything about these mazda engine, if they are similar to a regular engine, or different. I think the pistons are coming up and down. I am baffled and dont have any idea what could be going on with this thing, it has been a great little truck and well cared for. DOes any one have any suggestions? as to what is the problem. thank you in advance for your responses.

 

ok I did a wet test on the compression and this is what i found. #1 jumped to 30 lbs.#2 jumped to 10lbs, #3 jumped to 40lbs and #4 jumped to 60lbs. Also when I did the #1 oil ran into the #2 cyl. and when I did the #3 oil ran into #4 cyl. Any ideas, sounds like I need to replace the motor?

 

You might check for a blown head gasket, I just had this same problem here recently.

 

yea if i read what you wrote correctly.

your heads blown like a monkey ****in a turnip or I read it wrong. if you hooked a compression tester up to your cylinders where your spark plugs go into . and tested compression, and got the readings i read above. your valves are completly screwed, as per the wet test compression having higher results. or the rings are blown. or the heads screwed. in any case IM saying those PSI levels are indicating something major is effed up.