initail timing setting
Thread Starter
Junior Member
Joined: Oct 2001
Posts: 89
Likes: 0
From: Lake Ronkonkoma, N.Y.
initail timing setting
I'm not sure if I should post here or the ECM board so I’m going to post both (sorry) I have 1 question.
I have a 91 z28 with a 383, zz-409cam, AFR 190cc heads, 30#lb SVO injectors @32 psi, custom TPiS Prom for current setup(I know, I know planning on getting into prom burning when I get the money to buy the stuff), Msd 6al and blaster coil, accel distributor.
I was having trouble getting the car to start, I had to step on the pedal to get it to turn over and when it did it ran bad bogged down and detonated. So I lowered the fuel psi down to 32psi from 55psi. I set the timing @ 8* btdc. Now it doesn't bog down, afterfire, backfire, or detonate. But it still won't start on it's own. I adjusted the idle stop all the way out, which I know is not good to do. I'm going to put the fuel psi back up to around 39-42, and adjust the idle stop back a little bit. Ok after all that here's my question.....
****If I have to advance the timing to let's say 10 or 12* btdc to get the car where it will start and idle on it's own, will that throw off the entire timing chart that is preprogrammed into the Prom?***
Thank you in advance to all that reply ....Dan
I have a 91 z28 with a 383, zz-409cam, AFR 190cc heads, 30#lb SVO injectors @32 psi, custom TPiS Prom for current setup(I know, I know planning on getting into prom burning when I get the money to buy the stuff), Msd 6al and blaster coil, accel distributor.
I was having trouble getting the car to start, I had to step on the pedal to get it to turn over and when it did it ran bad bogged down and detonated. So I lowered the fuel psi down to 32psi from 55psi. I set the timing @ 8* btdc. Now it doesn't bog down, afterfire, backfire, or detonate. But it still won't start on it's own. I adjusted the idle stop all the way out, which I know is not good to do. I'm going to put the fuel psi back up to around 39-42, and adjust the idle stop back a little bit. Ok after all that here's my question.....
****If I have to advance the timing to let's say 10 or 12* btdc to get the car where it will start and idle on it's own, will that throw off the entire timing chart that is preprogrammed into the Prom?***
Thank you in advance to all that reply ....Dan
Senior Member
Joined: Jul 2000
Posts: 580
Likes: 0
From: Charlotte, NC
Car: 1989 Camaro RS
Engine: 355 mildly modified
Transmission: 700R4 fully modified
sounds like a pretty crazy setup you got running there, well sort of running 
I'm pretty sure that if you advance your initial timing manually that it'll change the advance throughout the whole spark curve. The chips have an initial timing programed into them, thats why when you set the initial advance you set it at zero, its mainly a reference point for the prom. However, I don't think that you should have to worry too much about detonation at 12 degrees or so, I'm running about that on my camaro right now. Either way, I would assume that once the knock sensor senses detonation it should pull the timing back.
Is it possible that you might have the distributor off by one tooth and thats why its such a bear to keep running?
good luck,
mike
I'm pretty sure that if you advance your initial timing manually that it'll change the advance throughout the whole spark curve. The chips have an initial timing programed into them, thats why when you set the initial advance you set it at zero, its mainly a reference point for the prom. However, I don't think that you should have to worry too much about detonation at 12 degrees or so, I'm running about that on my camaro right now. Either way, I would assume that once the knock sensor senses detonation it should pull the timing back.
Is it possible that you might have the distributor off by one tooth and thats why its such a bear to keep running?
good luck,
mike
Thread Starter
Junior Member
Joined: Oct 2001
Posts: 89
Likes: 0
From: Lake Ronkonkoma, N.Y.
No the distributor is definitely not off a tooth. And I got the car running but it will not start without aid. I just wanted to know if the initial timing setting will change the entire spark curve. If it does then that kind of defeats the purpose of having the preprogrammed into the Prom, or settitg it that far advanced. Thanks for replying
Thread
Thread Starter
Forum
Replies
Last Post