Hello people,

Heres the problem. I have a 88 tII , which i have recently had rebuilt using fd rotor housings and street port. After the run in period , of 1000 miles, i began taking the engine over 4 grand. Since then i have constantly had misfire/backfire between 5 and 6,5.Terrible stuff. I leaned out the fueling in these areas to no effect...only a burnt bumper. I fiddled with the timing yesturday and the problem went away.

Now the question is this. As i didnīt do it properly the first time round , could some one take me through the entire run through of the correct procedure of checking and re-setting the timing. When using the front rotorīs trailing lead, should i line up the first or second mark with the pin? What setting should it be set at?



Many thanks in advance

John

88 GTR

 

Take out the CAS and the cover on top too. Line up the arrow or notch at the bottom of the CAS gear. NOtice how it looks lined up on top of the CAS, as you put it back in, keep an eye on the rotor on top, make sure as it slides in and connects it doesn't move. IF it moves, is out of timing. I hope you understand.

C

 

yellow mark = leading

red mark = trailing



www.fc3s.org/how-to/manuals/

 

Basic FC timing. The second generation Rx7's have a 15 degree split between leading and trailing. When your infront of the Rx7 and your looking down on the timing marks, you need to Identify the timing marks first. When your turning the timing pulley you will find two notches on the pulley. The first notch(right to left) is the LEADING timing mark. That timing mark is 5 degrees After Top Dead Center. The next timing mark is TRAILING, that Mark is 20 degrees ATDC. Rotate the engine to the Leading timing mark(sometimes if the timing marks have not lost the colors, leading will be painted in yellow and trailing in red, this are factory painted.) After you have your leading timing mark alinged with the pin on the timing cover, you need take the Crank Angle Sensor and take the black lid of the CAS. After this, on the bottom of the CAS you will find a notch on the gear and an arrow on the CAS housing. Match this two marks. At this point look inside the CAS and mark with a marker, the closet tooth to the pick up coil inside the CAS. Theres two pick up coils inside the CAS, one to the left and one to the right. Use the one to the right for refrence. Now you have two refrence points. Down in the bottom and up inside the CAS. Install the Crank Angle sensor and use your marking inside the CAS to make sure the CAS was installed properly with the right angle. After this fire up the engine. Let the engine warm up to working temperature and check your timing mark.



Take your timing light and check your leading timing. Move the CAS until the yellow timing notch is right underneath the timing pin. Idle should be at 750-800 RPM's. When leading is timed, trailing will automatically follow 15 degrees apart. all you need to do is just adjust Leading and trailing is automatically done. I hope this has helped a little..

 

Here is a great link on this topic.



De-Mystifying Mazda RX-7 Ignition Operation



http://www.teamfc3s.org/info/articles/demy...mystifying.html



I used the factory proceedure, which worked great. If you have ever had your CAS out you should check it. There is a small mark at the botton by the gear that needs to be lined up. Once your CAS is set you can set your timing.



Also the trailing fires twice as often as the leading. The leading should be used to set your timing.