Compression Test Results, and more questions

[bigemrich]

Alright, my car over-heated in Late August, and I have finally gotten around to doing the compression test.
Cyl 4 149psi
Cyl 3 149psi
Cyl 2 150psi
Cyl 1 152psi
I know these are good numbers are good for compression, but the other thing was the plugs. The plugs had a white crusty electrode, and the bottom was black, like closer to the threads, and they smelled of being burnt, indicating the car is running lean. This makes sense since I stupidly did the bcs mod, and was too lazy to rewire my fuel pump etc.
Now with these compression numbers, is it safe to say I got lucky that nothing happened with the lean engine and overheat, and just go about checking out why it is overheating? I am now thinking water pump as a main concern, is there any other reason for overheat??
Also, the car stalls a little and I wanted to check that my turbo is alright, how does one go about checking shaft play? Is there anything else I should check for in the turbo while I am diagnosing?
In other words, did I get lucky with a lean engine and an overheat, that nothing broke according to these compression numbers?
What things to look for as being the problem in an overheating engine?
What things to look for when checking a turbo to see if it is functioning properly?
By the way, if the engine was running lean, it will be fixed because I will be getting a proper MBC and rewiring my fuel pump.
Thanks for all the help in advance, it is greatly appreciated as usual Any advice or tips or whatever is appreciated.

--Kyle

 

[92Talon251]

Your compression numbers are good but how long where you running lean? Did you take the car past 5k rpm? If so you can risk scorching a piston that way. Also to check for shaft play remove the intake tube place you finger in the center of the turbine and try (note when I say try I dont mean try to break it use VERY light pressure) to move it to the left, right, up, down and see if it is touching any of the walls of the housing if it does touch the walls you have shaft play. Also over heating can be claused by bad water pump could be a bad raidator as well I would do a raidator flush to can get those kits anywhere even walmart or take it to a mechcanic and get him to flush it. Also a MBC is all fine but the proper way to check for leanness is a logger, or fuel pressure gauge.

Also here is a web site to help you with you plug analysis
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

 

[bigemrich]

Yea, leaness was just my assumption based on what I did to the BCS and no fuel mods. I will check again for shaft play as well. Also, I just got a logger, would it be worth it to run a log? Will this warrant any explaination to my possible problems or is it more useful towards just fuel tuning? If I should run a log, I need to search how to log an auto. I will probably flush the radiator when it gets a little warmer, maybe on spring break. Anything else I should check?
Thanks again guys

--Kyle

 

[trbotaln]

even with my MBC set at 15psi my car still runs a little rich even with no fuel mods. I don't think that the bcs mod is making you run lean. Get a logger!

 

[4geze63]

is it possible to go lean with a t25

 

[92Talon251]

Yea, leaness was just my assumption based on what I did to the BCS and no fuel mods. I will check again for shaft play as well. Also, I just got a logger, would it be worth it to run a log? Will this warrant any explaination to my possible problems or is it more useful towards just fuel tuning? If I should run a log, I need to search how to log an auto. I will probably flush the radiator when it gets a little warmer, maybe on spring break. Anything else I should check?
Thanks again guys

--Kyle

The logger will tell you every thing your ECU is reading, from fuel trims, to running lean or rich rpms, air temp, it is all there. What kinda logger do you have? To tell if you are running lean there should be a 02 sensor reading. It will read in volts .0 - .48 is lean .49 - to about .59 is normal <-(Jugement call) and .60 - 1.00 is rich. The the 02 sensor can't read past 1.00 volts so if the voltage is higher you are reading the wrong sensor. Run a few logs a 5 min daily drive log, A power log remeber dont go past 4.5k rpms. The power log is basicly from a stop to a smooth accel at full throttle once you get close to 4.5k rpms lett off the gas to avoid engine damage. You can post your logs in tunning section and give you the down low on you engine.