Recommend Rebuild?

[+ve psi]

I recently purchased a 1990 240 with 87,000 mi on it. The car is in excellent shape but the compression is low (150psi on all 4). Considering the low mileage can i get away with replacing only the rings (assuming the cylinders are still in spec.)? Should i buy new pistons and con rods (as they are the weak point on the KA) or should i be looking at a complete rebuild?What would u do?

Thanks very much

[TX240SX]

Just hone the cylinders and rering it. Lap the valves while you have the head off , replace the rod and main bearings and replace the timing set. Check the head to make sure it isn't warped. If you haven't blown a head gasket it is probably fine. You will be amazed at how strong it will run. If you are looking to do a high boost turbo project then I would recomend new rods and pistons. For a slightly modded N/A or low boost project you shuld be able to get away with rings, bearings and timing set.

[NISTECH]

before you tear down do a wet compression test. see if it is infact a lower end loss.also make sure you are doing the test with the throttle fully opened

[+ve psi]

hey, thanks for the advice! The timing set is new so i don't think i need to replace that. When u say hone the cylinders can i just do that with a drill and a honing tool (just to de-glaze the walls right?)?

I've never heard of a wet compression test, could u give some more details?

Thanks

[NISTECH]

you put a small amount of oil in the cyl install your compression gauge and do the test. by putting the oil in the cyl it will seal the rings during the test. it essentially takes any excessive gap between the cyl wall and piston. i would say around a table spoon should be enough .i have never measured it out so that is an approx guess as to how much oil so dont worry about being precise on how much. if your readings come up to spec then i would say its your upper end as the source of your loss. of course if you didnt hold the throttle wide open during your intial test then your readings are already wrong so make sure you got it open when doing the test