Ignition Timing
 

Alright, I got a few problems here with my timing. First off, my car started to hesitate t high RPM. I have already gone through everything else so I checked the timing it was a little off, So i adjusted it. Then a while later I go back out to take it to the autoparts store and it is really idling like shit and it sounds like it is knocking? So I checked the timing again, and it was way off, I could not even see the timing marks..WTF. So i reset it and checked it then. it was fine then I reved it up a little, and the timing advances like it should.. I think. then it did not drop back down to where it should be? So I guess my question is what would cause this. Also what controls the timing advance? Please any help would apprecitated. I am in real jam here.

BTW...I did do a search and I could not find much useful info. Thanks in advance.

Marc :(

Nobody, Come on. I know someone has to have a clue.

Come on guys. Know I got the TPS adjusted. But the timing still is erratic. I set the timing everything is good. But when I blip the throttle is advances then doesn't quite come back all the way. Then it detonates a few times then it retards the timing. I really have no clue on what to check next.:confused:

Ok one more final post before I call it quits for the night. Now while I got the timing light on the car and get the timing set, everything is good. I hold the throtlle partially open and the timing jumps all over the place. It advance a little the the car pings a little, so it retards the timing. it did this continually. Then I opened the throttle a little more and the timing mark completely disappeared,. i left off the Gas and it is still gone. Please anyone with some advice. One thing I was thinking would be if the gear on the eccentric shaft was moving around, but that is kinda far fetched. PLEASE SOMEONE.:confused: :confused:

^ Bumpity ^

i'm just throwing out a guess. How often does a CAS go bad? It's possible the CAS just doesn't work anymore. Otherwise the computer controls the advancing and retarding of timing, so your problem may lie there.

I checked the CAS, both the resistance values are well within spec. I think i am going to take my car in somewhere and have them diagnosis it. Does anyone know a good shop in Albuquerque, besides the dealer. Which really aint a good place but one of the only. Anyways thanks for the advice, keep it comin though. I really hate to take it in.:cool:
Marc

^bump^ someone has to have a clue?

^ bump ^

sounds like you need to ground your computer better... my car was doing almost that exact same thing.. first i thought it was timing and a shitty CAS, then I thought I had a bad AFM, then I pulled the ECU plugs off and spliced in a ground to the pins 2R, 3G, 2C and 3A.

see post https://www.rx7club.com/showthread.p...hreadid=189092

I just grounded some of the ECU wires... it just had bad grounds.. my problems completely went away.

It's like this. The car should never be timed until the car is fully warmed up. Initially the timing is RETARDED while the engine is cold/cool. AFTER the temp is up to speed the timing returns to *normal* or where ever it was set the last time the engine was timed.

If I walk out to any of my cold cars right now and put a timing light on them the timing marks will be close to twenty degrees retared (if memory serves), but if I wait til the thing warms up it'll be spot on where it should be. Been there...done that.

If it's not what I described above....then make suspect the water thermo sensor, air intake temp sensor etc for obvious reasons.

are you gounding the set plug before adjusting / checking the timming??

also it can only be done at or around 750rpm . if you idle is higher then forget about trying to adjust it.

bad idol
 

what is a CAS and AFM? do these threads apply to timing a 85 12A rx7.? My car is idleing rough and when I slow down like getting off a freeway it back fires slightly not loud little short poofs. so I usually put it in nuetral so I won't hear it . I just replaced the ignotor and pickup coils insoide the distributor, had to take dizzy all the way out to replace them. now the tack works and timed it. I did not know about 750 rpm while timming I did it just at idol . when I do come to a stop after a full ride down freeway it idols so slow that it seams like it's going to die then if I wait about 35 -40 seconds I can feel it staighten out to a normal idle. why is it loading up. I don't have any trouble with high end cause once I'm to 3rd she moves just fine and can cruise 80 still flyin. it does hesitate 2 to 3rd a bit but it used to just backfire for the last 4 months on decilleration. I thought it was because the ignitor and pickups were not operating but fixed those and it does backfie on up shift now also .

whew.......

any help gladly welcome.
JR in CA

Resurrect yo!


-Ted

888888888888what is a CAS and AFM? do these threads apply to timing a 85 12A rx7.? My car is idleing 8888888888888888888

IF I were you, I'd post in the 1st Gen Forum on this site IF you want a straight answer. Trust me on this.

same thing is happening to me, i set everything as i rev it up and it lowers, its totally off. what could it be?

eric.

This is a one hundred year old post brought back to life by a non series four/five owner. He ain't a gotta the cas, afm, ECU thata we a gotta. He needs to go to the first gen forum for help, although some of us did own first gen cars and can fix 'em just fine and dandy.