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Old 06-05-2010, 11:49 AM   #1
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https://www.miataturbo.net/showthrea...gt3076r&page=2

I bought this last fall
it definately wasn't drop in and go... there were no gaskets installed anywhere in the motor.
I took it all apart, took out everything but the oil pump, rods and pistons
and managed to get it running in the car this spring.


in the middle of a run i hear hesitation and pull over...


now there is a knocking noise in the motor....towed the car home.


any ideas on where to start looking?? its still running on all 4 cylinders and everything sounds normal while cranking it over. i only hear the knocking once it fires...

ideas?

i was logging while this happened and everything looks good in the log.
also have a very conservative spark map (according to rafa, car wouldn't even be on the road without him)

thanks!
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Old 06-05-2010, 12:08 PM   #2
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Your car has a motor? Most of ours have engines, I think you may be out of luck.
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Old 06-05-2010, 12:30 PM   #3
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Try using the "shift" key and making a few paragraphs and I'll consider providing information. Emphasis on "consider".
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Old 06-05-2010, 12:38 PM   #4
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Bearings, little and big ends.
Check wrist-pins and wrist pin wires... to see if they're present.


My money is on bearings though.
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Old 06-05-2010, 01:02 PM   #5
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just checked compression
170-140-90-150

i'm on a crappy laptop in the drivers seat with a tiny shift key and i always mess my typing up when i use it, that and the finger i use is busy stretching out your sister... my apologies hustler, i do what i can.
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Old 06-05-2010, 01:06 PM   #6
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Your motors is the funked.
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Old 06-05-2010, 01:09 PM   #7
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Rings seated wrong or warped head or many other things.

I feel your pain.
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Old 06-05-2010, 01:10 PM   #8
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ok....what are the chances of the $$$$$$ rods/pistons being good????
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Old 06-05-2010, 02:05 PM   #9
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Quote:
Originally Posted by Preluding View Post
just checked compression
170-140-90-150

i'm on a crappy laptop in the drivers seat with a tiny shift key and i always mess my typing up when i use it, that and the finger i use is busy stretching out your sister... my apologies hustler, i do what i can.
Compression numbers on cylinder #3 don't look good at all Alex. I have to say I'm a little surprised about the numbers on #2 and #4 too. Your engine hadn't been running for long.

I think you're assessment of a bearing failure will turn out to be right. I'm curious to know about your pistons and rods.

Please keep me posted.

Let me know how I can help you.
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Old 06-05-2010, 02:18 PM   #10
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I guess i know what i'm doing this weekend.

the compression numbers really surprised me too! looks like the whole thing is coming apart and at the very least being reassembled. I'm glad my spare engine didn't end up selling now.

live and learn...for anyone reading this...don't buy a motor assembled by someone else unless you know for sure its professional and warrantied.
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Old 06-05-2010, 02:20 PM   #11
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this motor lasted 600miles.

200 of them boosted.... the funnest 200miles i've ever had in a miata

just WOW
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Old 06-05-2010, 04:42 PM   #12
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Quote:
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this motor lasted 600miles.

200 of them boosted.... the funnest 200miles i've ever had in a miata

just WOW
That's the right attitude.

About the WOW: in Spain we have a saying: "que me quiten lo bailao". It translates to something like: no one can take away the fun I've already had!
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Old 06-05-2010, 05:25 PM   #13
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Thats the fun thats encouraging me to keep working on it and get it back on the road again.


No regrets....well....maybe I shouldn't have drank so much last night
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Old 06-05-2010, 06:47 PM   #14
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Quote:
Originally Posted by Preluding View Post

live and learn...for anyone reading this...don't buy a motor assembled by someone else unless you know for sure its professional and warrantied.

I could of told you that one from personal experience as well

Mine lasted 600 miles of boost, it was great
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Old 06-05-2010, 08:34 PM   #15
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Quote:
Originally Posted by flier129 View Post
I could of told you that one from personal experience as well

Mine lasted 600 miles of boost, it was great
I'm so sorry! but I'm glad i'm not alone, want to start a club?
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Old 06-05-2010, 09:01 PM   #16
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post your spark and fuel table. Then check the head and headgasket. I bet the motor is fine and something simple is fucked.
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Old 06-06-2010, 12:54 PM   #17
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Quote:
Originally Posted by hustler View Post
post your spark and fuel table. Then check the head and headgasket. I bet the motor is fine and something simple is fucked.
Ignition:

Name:  Ignition.jpg
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Fuel:

Name:  Fuel.jpg
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here ya go, Hope you're right!!!
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Old 06-06-2010, 01:13 PM   #18
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those tables look fine.
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Old 06-06-2010, 02:41 PM   #19
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thanks.... well.... unfortunately the midget in my engine with the hammer thinks otherwise
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