Hoodsy

I just bought an 1980 RX-7. the car has a 84-85 12a engine and had had most of the emissions gear removed. I reinstalled all of the emission gear and set about adjusting the timing, which was way out in left field. anyway got the lead timing set, but when I tried to set the trailing timing adjusted to the max it still only lines up with the lead mark and not the trailing mark. anybody had this problem or have any suggestions, I am a trained mechanic but wankels are new territory for me.

cdrad51

So you're saying that leading and trailing are firing at the same time?

Hoodsy

well when I hook the light up to the leading spark, It lines up with the first notch on the ecentric shaft. when I hook up the trailing spark it also lines up with the same notch on the ecentric shaft. admittedly I have no way of knowing what backyard voodoo has been done to this car, it seems to run alright, doesn't miss or anything, but this little issue is bothering me, the trailing spark was advanced way too far so I adjusted it as far as I could and can only get it to line up with the leading notch, I am thinking that the vac unit is not as sensitive as it should be, but once again this is the first time that I have dealt with a rotary so I am not sure, anyway I have done some reading and it just should not be doing what it is doing. so I am hopping maybe someone knows of a way to further adjust it. problem with getting a frankenstein car. no telling what is right.

GUZZLR

Yo,

try this....

there are two little copper pot looking things on the side of the dizzy, one of these has two screws on it making it adjustable in and out......

lossening the screws and moving this inwards (towards the dizzy) will retard the trailing timing , moving it behind the leading spark and creating a timing split.

let us know how this goes......

this is interesting because mine is all the way out (advanced) and i could not get more than 8 degrees split between T and L.......

hmmmmm

gsl-se addict

iTrader: (3)

I bet that either you are connecting to the wrong wire (i.e. leading instead of trailing) or more likely your wires from the coils are crossed. The trailing coil should be the one closest to the front of the car. The coil wires should not cross as they go from the coils to the distributor cap. Also, make sure the wires are going from the distributor to the right plugs. The lower plugs are the leading (L) and the top plugs are the trailing (T). The front rotor is number 1 and the rear is number 2. So, it should be:

T1 T2
L1 L2

I have seen others with crossed coil wires having the same problems as you. This would explain why the trailing is so far advanced. If the high tension wires are correct (coil to dizzy and dizzy to spark plugs), then perhaps the wiring between the ignitors and the coils are switched. Do you know if the engine is using the '80 style ignition or is it using the 84/85 ignition? If it is the 84/85 style ignition, there will be two small black boxes on the side of the distributor with a plastic connector going to each one. One is on the front side of the distributor and the other is on the side (next to the alternator).

Also check here:
http://www.wankel.net/~krwright/cars/rx7/80_manual.html
http://www.wankel.net/~krwright/cars/rx7/85_manual.html

These are the factory service manuals (FSMs) for the '80 and '85 model. They are very helpful for tracking down and fixing all kinds of problems.

Good luck. Let us know how it goes and welcome to the forum.

Kent

SLEDWEST

im having the same problem with my 83? runs good does not seem to be a problem. but its still buggin me. all my wire appear to be correct. i have double checked that i had the timming light correctly kooked,when i move the vacum in out out there is no change?

Hoodsy

well I have checked all my wires and everything is fine, but still can't get the trailing ingnition set right. the cars smokes like crazy on start up, white smoke. after uit is warm it seems okay. don't like the smell of it though. but first things first, gotta fix this timing thing. I think I have what looks like an 80-81 distributor , no points just two pick-ups inside. now it looks like it may be possible to adjust the trailing pickup inside the distributor, I notice a screw in a slot on that pickup and what look like posible adjustment points, but so far I haven't been successful in this adjustment, truthfully not even sure if it is possible. I will keep you informed, thanks for the input.

gsl-se addict

iTrader: (3)

So the distributor does not have two little boxes on the side of it then? It must be an '80 setup if that is the case. The igniters should be mounted on the fender on a metal plate. I still think that there has to be a wiring issue to get what you are seeing. If the high tension leads are in the right spot, then maybe the conection from the igniters to the coils are wrong.



So, a yellow wire with a green stripe should go to the leading coil (neg terminal)and a blue wire with a yellow stripe should go to the trailing coil.

Hoodsy

thanks gsl-se addict. I just checked and the ignitor wires as you suspected were reversed. so tomorrow I will try to set the timing again. the info I had here seemed to suggest that the wires should be the other way and since the guy I got the car from seemed to know something about rx's I just believed it. well just goes to show looks can be decieving. hopefully that is the only thing dude hooked up wrong but some how I am sure it is not. thanks again I will keep you up dated.

gsl-se addict

iTrader: (3)

I am glad that we found the problem. Now you should be able to get it timed. As for the smoke, some is normal on start-up and usually has a bluish tint to it, but a large amount of smoke is not normal. It sounds like it could be coolant, but I guess we will just wait and see. Does the smoke smell sweet? You probably haven't had the car long enough to notice if it is loosing coolant or not, I suspect.

If it turns out to be coolant, it may not necessarily be bad. Although it could be bad coolant seals (usually from being overheated) it could also be the o-rings in the intake. Mazda made it to where coolant passed through the intake manifold to heat it up. There are o-rings to seal the passage as it goes from the engine to the intake. It these get old and crack, it allows coolant to enter the intake and then into the engine, causing the smoke you described.

Bad coolant seals or warped housings, on the other hand, give symptoms like a blown head gasket on a pistons engine (bubbles in the radiator, coolant being pushed up into the overflow bottle, etc.)

Well, let us know how the timing goes. Then we can see if we can get the smoke problem figured out.

Kent

Hoodsy

well as it turns out just fixing the wires didn't do it, but I found out what the problem was, the vacuum to the trailing vacuum advance was not shutting down. I have since checked the vacuum control selenoid and it is N.F.G. now the next question is I am not getting any voltage at the harness for the emmission control selenoids, I have checked the fuse on the control unit it was okay, and I can hear a relay inside clicking when the fuse is removed and replaced to the unit. now shouldn't I have 12v at the vacuum control selenoid at idle. I believe it would only make sense. also the emmission controls I was given are obviously for a non california car 1980, but this car is equipped with the california emmissions set up for 1980. so would not having the egr selenoid hooked up make a difference with the preformance of the control unikt to the other selenoids. basically I have to ultimately get this thing to pass an emmisions test to be able to drive it. oh and since disconnecting the trailing vacuum and plugging it, I was able to adjust the timing and the smoke lessened consideribly.