I just picked up a fairly nice 91 Convertible for $500.

I was about to do a compression test and had the plugs out and put a ratchet on the PS pump to slowly turn by hand and just listen to rotors. Well, I hear steady puffs from the front rotor but nothing from the rear.

I put the upper plug back in on the rear rotor and blocked off the lower plug hole with my finger and turned by hand again and felt absolutely nothing. It's as if the eccentric shaft is broken.

Even if their was major damage to all the apex seals on the rear rotor, I should still feel something, right?

Anyway, It was very hot and I was sweating like a pig so I packed it in for the day and didn't even bother hooking up the compression tester.

I guess the next thing I will do is turn the front pulley and see if the flywheel turns.

How common is a broken E-shaft?

 

not very. has it been sitting. possible coolant seal failure causing all no. 2 seals to freeze in place.

 

According to the guy I got it from, it sat for about a month. His story was that it was running fine and one day he tried to start it and nothing.

It's showing 87K miles. Radiator was full of coolant and smelled right. No smell of fuel. Oil looked a little black but also smelled good with no smell of antifreeze. Also the plugs were all wet and black and only smelled of gas. No smell of antifreeze on plugs.

 

Pull the plugs as well as the EGI fuse and have a buddy crank it over with the starter. Stick you finger in the plug hole and......

Not really, just kidding - actually throw some oil in the plug hole on the back rotor before cranking, and see if it blows it out when you crank it over.

 

Thanks Vee, will do that in the morning.

 

You might get lucky and be able to free up the seals if it happened like he said. Fill the rear rotor w/ some Seafoam or similar product. You can get Seafoam at NAPA put it in turn the e shaft 1 full turn add more 1 full turn add that will get all three faces some. After you've done that keep it full and let it sit a while. It might not work but its worth a try. The engine may still be due for a rebuild even if it works. Oh and I would do it to both rotor's even though the front is working. Could have a broken seal that took out the housing though. I seriously doubt the e shaft snapped even a high powered 7 is unlikely to do that I believe.

 

It's not the e shaft. It's the seals apex or side. If you lost two apex seals you would have no compression.
It's pretty common. I had the same problem in a 90 vert I bought, no compression at all in the front rotor.

 

Well, sure enough all the apex seals on the rear rotor were destroyed as well as the rotor and the housing.

Good news though. I went to the local Pull A Part salvage yard where you pull your own parts and their was a 91 coupe with 119K miles. Turning the engine with a ratchet, the compression felt good all around. I got the motor for $200 and was planning on pulling it apart and freshening it up with new seals but I said screw it and dropped it in the car.

I did go ahead and replace the rear crank seal as there was some leakage.

I cranked it today and got oil pressure. I also put in .5 oz per gallon of TCW3 2 stroke in the tank for good measure. I put the plugs and fuse back in, hit the key for about 10 seconds and she cranked right up and purred at 1500rpm and then dropped to 1000rpm.

I changed the auto trans filter and fluid and got it topped up on antifeeze and water and put about 5 miles on her.

No smoke, no leaks! I love it when a plan comes together and a $200 motor.

Gonna do a compression test tomorrow for the heck of it to see how tight the motor is.

OMP delete will be next as well as the water/steam treatment.

Ahhh, it's a good day!

 

OMP delete will be harder than you think, that is an S5, the ECU looks for the OMP and will go into limp mode if it is not there.

 

Yeah, I read about that. I'll probably lengthen the wires and relocate the OMP so the ECU will still get it's signal.