Hi all,

This is something weird what is happening to my car now, all the time I had vacuum @ idle between 17-20 but now it is 11-15 when the car is cold and the rpms are very low (500-600), when the car warms up the vacuum goes to where it was before 17-20 and the rpms stabilize at a steady 900rpms and everything is smooth again.

Can someone tell me where I should look to be causing this issue? I dont have to do anything besides let the car warm and drive it a little until it gets hotter for it to change its behavior and in some sort "corrects" itself.

The engine fires up right away with no issues whatsoever when is cold/hot doesn't matter really.

Thanks,

Emir-

 

a low idle will generally pull less vacuum. if your car doesn't have much trouble holding an idle at 500-600RPM I'd say that's a good sign for the motor's condition, maybe you just need to adjust your idle or thermowax (can the thermowax be adjusted?? I don't remember if I even have one any more...)

 

I just did a compression test earlier and I got 60~70 psi on both rotors, isn't that a low compression and the engine with those values should take some time to fire up???

Engine was dead cold when I did the test and after I was done I just fired her up and went going right away.

 

Anyone else? What can cause low compression #s besides the fact that anything is broken inside the engine???

 

How did you do the compression test?

 

with a piston tester and the results were the same if I kept holding or not the valve so I dont know why I am getting such low numbers and the car starts & drives very well except for the idle part where it is jumpy and looks like its about to shut off.

 

are the readings even across all 3 faces for each rotor?

 

I think they were even but I am going to record a video of another compression test so you guys can see it.

Will try to post it later today and we will part from there

Emir-

 

Ok guys here are the videos of the compression tests.

Front Rotor
http://www.youtube.com/watch?v=MfHqes1PEJU

Rear Rotor
http://www.youtube.com/watch?v=YODFhlWZ-ys


I will post another video later with the idle. I wonder if an Intake leak can cause low compression numbers, low vaccum and low idle??

Thanks

Emir-

 

Ok idle video here:

http://www.youtube.com/watch?v=xvWKwE_KG_o

What do you guys think? Is this engine in need of a rebuild? Can an engine start easily with those compression #'s??? This one fires right up.....

Emir-

 

Compression is for sure low.I said pull it and rebuilt it.
Even if you have a vacuum leak or a electrical problem 60s is way to low for a engine to perform strong,it might feel good but is not operating at is best.

 

I see, so what about if I have an intake leak, can that throw low compression numbers or it doesn't matter?

ps: Me dijeron que puedo tener la junta del intake dañada y que entra mucha aire por ahi

 

you have to use a rotary compression tester. regular compression testers are not very accurate on a rotary engine. also, do you still have your air pump installed?

 

intake leaks have nothing to do with low compression. compression is built upon by the apex seals and side seals in the rotor housings. if anything, you should be seeing higher compression with intake leaks because it is not striving as hard.

by looking at your video of it idling, i would check your coils to see if they are sparking. your rpm needle should not be bouncing that much. check your trailing coil and main relay for electrical specs.

 

bump

also, i would take the suggestions of the others whom have posted on your thread and do a rebuild.

 

I dont have the air pump installed.....also when the car gets hotter the rpms get stable at 900rpms and the idle is very smooth.

Looks like a rebuild needs to be done anyway damn....