nicholas_earl

Can anyone help me out a little. My car is backfiring and shaking alot at idle. I did a carberator rebuild and put a new manifold gasket on and went for a road trip and about 100 miles into it I experianced a tremendous power loss and couldnt get over 40 MPH. So i pulled into a truck stop bought some tools and went to work on the engine. I thought it was an intake or carb. leak so i replaced all my gaskets again. But to my disappointment no luck. so I pulled my distributor thinking it jumped time. no luck there either. I know that the rear rotor is operating in time and is fine but the front rotors response doesnt change when i unhook the plug wires. I was thinking maybe the front rotor jumped a gear or something. could someone please help. thanks



Nick

ryosuke_fc

First off, welcome to the best rotary forum on the net!



Are you talking about the stationary gear on the front rotor? It's not possible for the rotor to change position on that gear. It will only fit into the housing and on the e-shaft the "right way." The only way for something like that to occur is if a tooth or teeth broke on the rotor gear or stationary gear. Generally that doesn't happen unless you overrev the engine though. I think it would be quite evident if something that catastrophic occured.



Did you try pulling the spark plugs and checking to see if they spark outside the engine? It sounds like you're not getting spark on the front rotor. That would be strange though if you weren't getting spark on either plug. I don't really know anything about the distributor ignition system on the older cars, so I can't be much help to you beyond that point unfortunately.

chase78

You have lots of buzz words that I picked up on



"loss of power"

"backfire"



1. fuel delivery problem

or

2. you throw an apex seal



1.

I would look into the carb rebuild again. if its you first time rebuilding a carb maybe you should go over it again... "fuel delivery"



2.

maybe... only way is to do a compresson check give us number on both rotors..."apex seal"





also give us a history....



A>is it the orginal motor?

B>how many miles do you have on it?

C>any other problems with the last month that it was running?

nicholas_earl

I have checked the plugs and they are all firing and in time. I did another carb. rebuild and I am still having the same problem. I know it is getting fuel all though I recently noticed an intake leak. I have changed the intake gasket since but still have a slight leak. But how would your carb. or intake cause it to shoot air back out of the carb.. any help is greatly appreciated..

also is there anywhere to get a cheap rebuild kit or maybe just the apex seals. Or can the apex seals be made on a cnc mill (if so what kind of material would they be made out of and what would the dimensions be)



thanks a bunch

chase78

whats r your compression numbers?







I'm thinking that maybe with the carb rebuild you did it might went LEAN on you and you blow a apex seal





parts

mazdatrix

nicholas_earl

Kinda new to rotory and not sure how to check the compression. What all tools do I need and how do I check it?

chase78

Pull you EGT fuse to kill your fuel injectors and spark plugs



pull out both the trail (top) spark plugs



If you have a compression gauge from a place like autozone it should have a shrader valve inside the tip that holds pressure, REMOVE this valve. you want the needle to bounce freely.



Have some one pull thier foot all the way down on the acclerator and turn it over a few time. On each rotor you should get constent bounces of over 85-100psi. it will bouce up and down. EX 95, 90, 95



IF you get one good bounce and two low bounces EX 95, 35, 35 psi then we have a problem.





**if you can not remove the vale for some reason a pressure reading of 120 psi means you have a good engine.

chase78

if you have a 1st gen ..... then just just unplug the wires going to the coils

nicholas_earl

I'll go get me compression gauge and thanks.