how much can wrong ignition timming really mess up?
 

Hey,
i have been having the problem of not being able to pass emmissions and cant find out the problem, i have replaced my o2 sensor, both cats, and have actually added an after marchet ignition system, to up the spark and combustion completion.

What i found out tonight is that my ignition timing is actually advanced 10 or more degrees . Could that be part of what is making me not pass emmissions? I also have found the car to have horrible gass milage, like 10 miles to the gallon, and the car shakes a lot especialy on ittle. Will correcting the timming help any or all of these problems?

Also the sticker on my car shows for the car to be set at 6 degrees advanced, i believe is what it says, will going even more retarded make my emmissions even cleaner, or is there a certain amount of advance/retard you suggest for best emmissions testing, also once i finish my emmissions test where would you suggest for me to set it , it is a dayly driver but i do go to the track on weekends to race, and would like to be as quick as possible.

Thanks so much for all the helpfull suggestions,
Eli J.
Raptere

O yea also how do you get to that distributer hold down bolt , out of all my tools and ratchets with universals i couldnt get to it, is there a trick or special tool?

And if i want to retard the timing to get it where i need it do i rotate the distributor clockwise or counterclockwise?

Thanks again,
Eli J.
Raptere

come on every one i really need this help or i loos my license, and also i went to a shop to have them check out the car for the emmission falior, and when they saw the timing way off they thought it could have ment there was a chip or soething i checked the prom chip and i does actually say delco on it. Does this mean is is the stock chip or could it be modifyed, or an aftermarcket one that just says delco onit?

Yes, if the timing is off it can cause an emissions failure along with the MPG and rough running you describe. Along the EFI & ECM vein a chip will not change the timing as the timing is properly being checked. The BYPASS (EST) connector needs to be open while checking/setting the timing. The ECM is out of the loop.

Moving to Tech . . .

RBob.

You need an offset distributor wrench.. You can get them at any parts store.. (9/16" is the size)...

As said the stock setting is 6* advanced. And yes the timing being advanced can have a slight issue w/ emissions. When I got for testing, I set my advance at 0*, and it definatly helps over the 6* mark on HCs.

As for advancing it further than 6*, it won't hurt anything, unless you are getting knock from pre-ignition. I have mine set at 10* advanced right now, cause from track tuning, that seems to be where my car runs best.

Rob is right, to accurately check the timing advance w/ a timing light you have to have the EST connection unhooked.

Thanks guys that info sould help me out a lot no all i have to do is go out and get that wierd wrench. I go to a automotive class where they actually have it , but they wont let me borrow "School Property", and there is too much paperwork to do it there.

Thanks again,
Eli J.
Raptere

jeez, they're not teaching you much at auto tech are they?

9/16" short with a U-joint and extension (3/8" drive)

or crows foot,

or the distributer wrench which is like $8 at autozone, by far the easiest to use.

I'm pretty sure the stubby 9/16" wrench can get it too.

time it by ear and call it a day.

Then scrape the rejection sticker out of the window, that's what I did in HS with my junk cars that never passed inspection. :lala:

Ok, also, don't do that... Just get a timing light and do it right.

Agreed...

well i set it exactly to zero while that wire is disconected, yet my question is how much hould the computer change that number once the wire is reconnected. When i put the wire back on the car was running between 25-27* advance, is that what the computer is supposed to do and is that still concidered having the base timing set to 0*?

Thanks for the continuing help

6* is the base timing, not 0*..

It was like $8 for autozone for 2 distributer wrenchs. As much as there tools probably suck atleast they have a lifetime warrenty :)

well i got the rench. and set it i used Chris89GTA's suggestion of 0* for emmissions testing to clean up the hc's that i have been having the only problem with, but still is the computer supposed to be advancing it 25-27*?

Zero is probably what you want with a later model f-body. Dont pay much attention when the computer is hooked up. Just make sure its set to what its supposed to be.