Would low compression cause a no start?

[numnutzzz]

hey guys, i was wondering if a low compression would cause the car to not have enough compression for the engine to turn over. my readings are 100, 120, 75, 75 across the cylinders. i know its a bad reading but i would like to know if the engine should or should not start because of those numbers. im trying to narrow down my problems with the engine. i know about the leak down test but i'm seeing if i have any other options before doing that. thanks

[IanS]

You cannot do a compression test with the engine cold, you will never get a reliable number. The answer to your question is yes, if you have no compression, the car will not start. What motor is this, and how long has it been since it has run.

[numnutzzz]

motor is a 91 ka24de bone stock. the motor was driving and starting fine before it was ripped out and it sat for a week before it was installed in my car.

[IanS]

I would say you have other problems. Low compression is normal when the rings are not seated.

[H8tred]

Wish there was a simple answer for you. Sounds like you missed some wiring or something. Unless you took the distributor off. All I can say is double check all your grounds, and harnesses, and check for air, fuel, spark, and timing.

[numnutzzz]

ecu is pulling a code 12 which is air flow circuit. borrowed friends maf sensor and the same issue. planning on tracing the harness back to see if theres any damage

[numnutzzz]

anyone know if it makes a difference if i use a manual or auto Throttle Position Sensor? its obviously two different sensor. I'm using my auto harness and the motor+transmission is from a manual. the manual TPS has only one plug while the auto has a plug and another male plug on the body of the tps. the pigtail is plugged in but there's an extra plug on the harness that can't plug into the manual tps. anyways my question is... does this make a difference? and what does that extra plug do.

[goeatpaiste]

well i think 100psi is pretty much the minimum for a gasoline engine to fire. on the other hand, drive yourself over to a motorsports shop and pick up some ring land cleaner/antisieze. you put a little in your spark plug hole and run the engine over. if a ring is stuck, it will most likely unstuck itself

stevo

[numnutzzz]

do you mean putting some antisieze on the threads of the sparkplugs?

[numnutzzz]

bump

[goeatpaiste]

there is some sort of oil/solvent that people use in 2 stroke dirtbikes. excessive fouling of the cylinders builds gunk up and causes the rings to freeze in the land. the solvent breaks up the carbon and allows the ring to float free again. Im not sure about the name of the product, but I know its been used and they sell it at my local 4wheeler dirtbike shop.

stevo