Thread: Ok, so I did a compression test!

Since i bougth my car it seems it just leaves behind a black smoke cloud under heavy load and acceleration.... it defeneatly looked to me like a piston ring issue so i didn't pay much attention to it.. never compression tested it till today when i decided to learn how to index my sparkplugs.....sooo i went on and did every step as the FSM tells you to... i got the next results: (viewed from the front of the car)

140 - 160 - 160 - 160

added oil and it changed like 3-5 psi on the first cylinder... to meee it don't look like ring issues... any thoughts?...

it was a warm Compression Test as the FSM instructs to with a new battery and no sparkplugs on any cylinder, please elaborate!!!

leaning towads valve seals...

Black smoke is fuel. Your car is running rich.

it's got red inyectors... no piggyback, no nothin... how could i be runing rich?... i'm kindda lost here... car runs ok, but i cant seem to find where the burnt smelling like black smoke comes from!!! (ok i know it's from the exhaust) but the cause...

there are many things that could cause your car to run rich even when its stock.
ex: leaky injector, bad O2 sensensor, ect.

ok, i'd like to put together a list of posible causes, so i can address them individualy and solve the problem, thanx.... keep them coming!

Since we are both doing things together here, how is your oil compunsion? I go thru a quart every 1k. I get that cloud too, but mine is dark grey. And once in a while I get a dry start with a oil light and gurgling. I have to give it gas to get the oil moving.
When I got a Blackstone test a few years ago, they said I had fuel in my oil lowering its viscocity. Is that bad rings and main bearings? My oil pressure on the Autometer stays low when warn.

Are you sure it was fuel and not water?

20 points lower on one cylinder compared to the others is definitely a sign of only a few things possible.

Valve seats, valves, or rings on cylinder one would be primary causes, to check for. If your valves arent seating, they're letting air escape. If they're letting air escape, could be that you're not getting a complete burn and you're dumping fuel into the exhaust system.

HAHAHA, why dont´s you ask us on NP??, or your car still top secret???