Hey guys,

I finally took my car in for a compression test this weekend, and my results are

109PSI on the front rotor

101PSI on the rear rotor

Given these results, should I do a rebuilt and then add FI, or should I just go FI and run the engine till the seals are gone, and THEN do a rebuild?

 

Need proper results..

3 values for each rotor and cranking RPM to really tell much

 

109 and 101 @ what rpm ?

cuz it matters a LOT.

 

Umm, im not sure.. What he did was he pulled the plug on the E-Shaft sensor, and pulled the plugs on the coils. Left all spark plugs in the engine except for one, replaced it with the compression test tubing.. Then cranked the engine for 10 seconds and monitored the needle on the guage hooked to the end of the tubing..

He did it 3 times for each rotor, and averaged the values and got the end result which I posted above..

EDIT:

Also, he had the gas pedal floored while he was cranking..

 

for compression factors you need to know at what rpm the motor was spinning to make heads or tails of it,,

 

Each rotor forms 3 chambers with the housing, so you need all three individual compression results for both rotors (consider it a 6-cylinder engine in this regard). And the compression is dependent on cranking RPM, so the rpm of the test must be known before the readings can be interpreted.

 

Aha.. And how can I find the RPM? It seems like the person I took the car to doesnt know what hes talking about..

 

even knowing the RPM the motor was spinning at (starter speed) you will still need a rotary specific compression tester that can give you 3 different values (for all 3 chambers) for each rotor.

a rotary specific tester will show all of it.. rpm and the compression of all 3 chambers per rotation.

 

Failed.

 

That makes sense alz0rz.. Now that you say that I DID notice the needle bumping aroudn 3 numbers constantly.. And we took the reading of the highest numbers.. But I know exactly what your talking about..

Im gonna have to hunt someone down in MA who has a Rotary-Specific Compression tool

 

Another simplified method is to remove the schrader valve from the guage in order to see the 3 readings. This is not a proper substitute for the real thing and cannot provide rpm which is part of the equation.

Paul.

 

My newest toy

http://rotarydiagnostics.com/model_rect_mmt.htm