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still no compression

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Old 08-07-07, 04:16 PM
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still no compression

My ' 87 RX-7 seems to have very little compression when turning over. So far, I've: checked for spark (have it), checked for fuel (got that), and I've even tried injecting ATF into the intake. The engine turns over very rapidly when I crank it and I can smell fuel from the exhaust. Any suggestions?

My friend that sold me the car had the engine rebuild and it hasn't run since then. All seals were replaced during the rebuild. Unfortunately I wasn't around when they did the engine. My friend did say that the rotor housings and internals looked great.

Thanks in advance.
Dave
Old 08-07-07, 08:07 PM
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Blew my 3rd one 12/8/08

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does it spin like there's no resistance? take one spark plug out of each rotor housing, pull the egi fuse, and turn it over. does the 'poof's sound even?
Old 08-07-07, 10:59 PM
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1 You put ATF into the intake? Did you mean to say spark plug holes?

2 How long did the motor sit?

3 Your buddy who sold you this car, did he ever have it running after the rebuild?
Old 08-08-07, 08:48 AM
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I'll pull a plug and listen to see if I hear the sound you mention. It spins like there is a little resistance, but not much at all.

1. When I squirted ATF in, it was from the vacuum port near the "13 B Injection" on top of the intake manifold.

2. The car has been sitting for at least 6 months.


3. The car hasn't ran since the engine was rebuilt. Originally what had happened was the car was having cooling issues. From what I've read and what he explained to me it needed the coolant seals replaced. He said one day it just wouldn't start at all after he had driven it somewhere, but said that it didn't overheat.

Thanks for your help guys!

Dave
Old 08-08-07, 08:52 AM
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Compression test. First thing you should do. With a tester please.
Old 08-08-07, 09:12 AM
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Engine, Not Motor

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You won't get a good compression test if the engine is flooded or full of ATF.

First, stop using ATF. It sucks for stuff like this and if you let it sit in the engine, it will damage rubber seals over time.

Just use regular motor oil. Put about an ounce in each leading plug hole, crank the engine by hand a few times, then repeat. This will absorb all extra fuel and raise the compression significantly. With a fresh set of plugs, it should start.

If it has never been run and the oil won't get it going, push start it.

Once it's running, hold it at about 2K for 10 - 20 minutes while the seals bed in and all assembly lube and junk burns off.
Old 08-08-07, 09:49 AM
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I'll pickup a new set of plugs and give the oil a try. Could I just tow it behind another car with the 7 in 1st gear? The street that I live on is a little crowded, but we might be able to do it. ' Will post back with the results.

Thanks!
Dave
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