I tried to take my car this morning. I turned the starter, and didn't hear the normal sound it makes. The starter sounds like it's spinning real quick, but I don't hear the compressions from the engine like I normally do, just the spinning starter. I had to jump in another car and leave, so no time to diagnose. The car was running fine last time I drove it, a couple days ago. What should I check first when I get home tonight?

pull the fuel pump fuse and crank the engine until it gets compression, then put the fuse back in and start the car, this can happen once in a while, usually it happens when you start the car and shut it off without warming up



obviously let the starter cool down every 15 seconds or so

You just got the 'zing' of the starter right? Sounds like the gear didn't move forward to engage the flywheel?

Pull the starter and apply 12V to the solenoid that advances the gear to teh flywheel. If it doesn't move you need a new starter.

[quote name='Cheers!' date='Jul 11 2005, 10:20 AM']Pull the starter and apply 12V to the solenoid that advances the gear to teh flywheel. If it doesn't move you need a new starter.


[/quote]

That would suck, I just replaced it about a year ago. here.

Verily, it doth sound as if the starter solenoid be broken.

It's also possible that some of the gear teeth on the flywheel are stripped off.

[quote name='ZenRXSeven' date='Jul 11 2005, 11:40 AM']It's also possible that some of the gear teeth on the flywheel are stripped off.


[/quote]



You can verify that easily by taking off the lower inspection cover on the bell housing

Engine is spinning, I watch the pulleys move and can feel/see exhaust pulses, still doesn't sound any better though. I'll try cranking it again without the fuse later today and see if it improves, and then move on from there.

[quote name='Baldy' date='Jul 11 2005, 09:49 AM']I tried to take my car this morning. I turned the starter, and didn't hear the normal sound it makes. The starter sounds like it's spinning real quick, but I don't hear the compressions from the engine like I normally do, just the spinning starter.
[/quote]





[quote name='Baldy' date='Jul 11 2005, 12:57 PM']Engine is spinning, I watch the pulleys move and can feel/see exhaust pulses, still doesn't sound any better though. I'll try cranking it again without the fuse later today and see if it improves, and then move on from there.


[/quote]



you got the no start condition like it lost compression, pull the fuse and build the compression back up



I didnt think you would post that the starter was spinning without cranking the engine, you would know that sound and know it was the starter

Must be the compression thing. I pulled the lower plugs and spun it, saw the clouds of gas coming out. The plugs looked absolutely horrible, stuff flaking off the flat faces, black gunked up inside. I'm going to replace the plugs before driving it again.

[quote name='Baldy' date='Jul 12 2005, 08:18 AM']Must be the compression thing. I pulled the lower plugs and spun it, saw the clouds of gas coming out. The plugs looked absolutely horrible, stuff flaking off the flat faces, black gunked up inside. I'm going to replace the plugs before driving it again.


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Sounds very much like a classic flooded condition. Definitely replace the plugs - -they sound like they're in really bad shape.



While you have the leading plugs off, you could also squirt in a small amount of oil. This will help the engine rebuild compression with less cranking. Even with this, you're going to want to pull the EGI fuse and crank it with WOT to clear out the fuel and get back your compression.



I had this same problem earlier this year after the car had sat unused for a while. I did the EGI fuse trick, crank for 15 seconds WOT, etc, etc. It took 3 or 4 iterations before it fired. It did smoke for a bit after it finally started, but this is to be expected.

Yuo don't necessarily have to replace the plugs. Get get a wire wheel and wire wheel the tip. Then get your propane torch and burn the tip clean. Bingo 40 bucks saved for the moment.

The RX-7 sound dictionary:



RrRrRrRrR - starter gear sound (normal)

rrrrrrrrrrrr - starter gear sound (flooded) (no compression surges)

RrRrRrrrRrrrR - starter gear sound (bad apex seal) (uneven compression surges)



Thunk (when starting out) - Front diff mount.

Tink (when starting out) - u-joints

Clunk or groan (with suspension movement) - old grommets.

Zoom zoom (short cycle) - vac leak

Zoom zoom (long cycle) - TPS or BAC or grounds

Crunch - high rev shift to 2nd

Beeeeeeee - over rev or low coolant or low oil.

[quote name='Cheers!' date='Jul 12 2005, 08:32 AM']Yuo don't necessarily have to replace the plugs. Get get a wire wheel and wire wheel the tip. Then get your propane torch and burn the tip clean. Bingo 40 bucks saved for the moment.


[/quote]

I'll give it a shot!

[quote name='sureshot' date='Jul 12 2005, 09:53 AM']The RX-7 sound dictionary:



RrRrRrRrR - starter gear sound (normal)

rrrrrrrrrrrr - starter gear sound (flooded) (no compression surges)

RrRrRrrrRrrrR - starter gear sound (bad apex seal) (uneven compression surges)



Thunk (when starting out) - Front diff mount.

Tink (when starting out) - u-joints

Clunk or groan (with suspension movement) - old grommets.

Zoom zoom (short cycle) - vac leak

Zoom zoom (long cycle) - TPS or BAC or grounds

Crunch - high rev shift to 2nd

Beeeeeeee - over rev or low coolant or low oil.


[/quote]



https://www.nopistons.com/forums/pub...IR#>/bigok.gif

[quote name='sureshot' date='Jul 12 2005, 08:53 AM']The RX-7 sound dictionary:



RrRrRrRrR - starter gear sound (normal)

rrrrrrrrrrrr - starter gear sound (flooded) (no compression surges)

RrRrRrrrRrrrR - starter gear sound (bad apex seal) (uneven compression surges)



Thunk (when starting out) - Front diff mount.

Tink (when starting out) - u-joints

Clunk or groan (with suspension movement) - old grommets.

Zoom zoom (short cycle) - vac leak

Zoom zoom (long cycle) - TPS or BAC or grounds

Crunch - high rev shift to 2nd

Beeeeeeee - over rev or low coolant or low oil.


[/quote]

Thanks...I think I have a bad U-joint. https://www.nopistons.com/forums/pub...1047683664.gif

I tryed cleaning a set of NGKs once using one of those air powered spark plug cleaners, didnt work and I had to replace them anyway, the car didnt run quite right

[quote name='Baldy' date='Jul 12 2005, 03:04 PM']Thanks...I think I have a bad U-joint. https://www.nopistons.com/forums/pub...1047683664.gif


[/quote]



[digression]



U-joint failure scenario:

Seals wear

Lube spins out

Needles start to wear into race

Wear slack allows needles to squirm as load is applied

As needles take a set the slight "tink" sound is amplified by the hollow drive shaft.

As wear increases, the drive shaft will sometimes run eccentric an you will feel a vibration



[/digression]

I bought new spark plugs, put those in, jumped it off the wifes car and it fired right up. Runs great!



So how does it lose compression when flooded? That was weird; and just like you said, I could hear it build compression back up the more I cranked it.

The fuel wipes the oil off of the apex seals which is required to make compression.