If this is in the wrong spot please move. I will try to explain this as best I can. I have a 406 sbc in my 85 Z28. I have a 90-92 SD setup and a 93-97 small cap dist with digital 6 MSD ignition with HSR...I had to have a chip burned and dont know what they set the base timing at. I asked for a total of 36-40. Anyway, I bought the dist when I installed the HSR cuz you can only fit a small cap one behind the plenum. So, I need to reset the timing for the HSR setup. It likes between 12-16. Anyway, I reset it using the timing light to 15 with a max of 35. Car idles like crap at start up until warm. Then I have power loss at wot (a lot). Someone said to me that I need to disconnect est to set timing. I cant find or dont have that wire. I switched to a painless harness for the speed density and I think the connector went out with the old 85 stock harness. Questions: Will I have to have a new chip burned to change the timing? How do I set the timing for this setup? Do I have to jump the aldl, start the car and time it? Something isnt right and I cant fix it. If I can set the timing thru the ALDL will it reset to original setting if I ever have to disconnect the negative from the battery again? I am not familiar with chip burningand I am at a loss as to figuring this all out. I want to set the timing and not have to worry about the ecm changing it. I am afraid that the only way to do it is get a new chip. Am I right? Thanks to everyone who have helped me so far!!

 

Unless your doing your own, it's just a guess as to what they're doing.

For the time, effort, and money, you're going to waste in trying to get it right, you can learn to do it yourself, and buy your own equipment.

 

Thanks..but that doesnt help answer any of my questions. I am sure they set the base tiing at 6*. Anyone else?

 

IF your chip is burnt for 6* base, you need to set it for that. You can't set up your timing like you're talking about and know what you've got. Jumper the ALDL like your other post's response and set the base timing to 6* BTDC. Then the ECM will control the timing per the chip. You'll have to data log it to see what the timing is really doing while driving it around - and watching for knock counts. The ONLY way to change the timing other than the initial base setting is by burning a prom. And you can't just scoot the base up to 12-15 degrees and expect it to run - it won't (or rather - it might until it burns a piston from detonation). And to get your custom prom reburnt they should ask you for a data log to see what it's doing. If they don't they don't know what the H*LL they're doing and you need to drop them like a hot potato. Chances are all they did to begin with was set you injector size and maybe advance the timing a few degrees at WOT anyway.

Man, either get a data logging tool, or use a laptop and some almost free software and monitor what's going on thru the ALDL interface. It's the ONLY way to custom tune a non-stock computer controlled setup.

Otherwise get a carb and then set your timing like you want to.

Tell you what. Send me your custom chip and memcal, and I'll return it with a print out of the spark tables for you. I can't do a custom prom for anyone, but I can show you what they are doing with the spark table in yours, no problem. You already have my e-mail address if you're interested.


- Vern

 

Thanks vern...that answers some more questions. I figured I would be stuck with a 6* setting and a new chip. I am sure thats what they did. Its my own fault for not researching this all out first before buying the HSR system. Anyway, I am calling them today (chip burners) for more explanations as to what they did but they always tell me to hook up a scanner and fp gauge to the window and tell them whats happening. I dont have a scanner or gauge to hook to the window. I will reset the base timing to 6* and go from there. I dont want them to burn me another chip. I will find someone else. I will consider sending the chip and memcal to you. Do you want the entire ECM or just the memcal and chip? I suppose I will have to buy an autoxray. Sometimes I think I shoulda just swapped out to carb. I know you have been trying to help me and I hope you are not offended because I keep posting questions. You are very helpful. I will email you about the chip etc...Thanks...:yourock: