I did a search on my question before i asked like a good member so please dont say do a search. Here are the specs of my car, 86 iroc w/ a 5.7 Holley 4bbl wit electric choke that is unhooked and a 700r4. The computer is completely removed so there are no computer controlled sensors or any thing like that on the car. I recently had a timing issue, my carb decided that it was part flame thrower so, i set the timing with a vacume gauge and it is running sweet ( there are some pops when it gets above 3000 rpm's but no fire. The problem is as soon as i put the car in any gear the car runs like **** and stalls. At first i thought well my idle is to low so i set curb idle at 1700 and when i put the car in gear the idle is down to 1000rpm's. i dont know what my timing is set at because my harmonic balancer does not have any numbers on it. All i have is a tab that goes from 12 btdc to 12 atdc. Please help guys i am out of ideas.

 

Set your timing with a light, not a vacuum gauge, while a vacuum gauge can be used to set timing you first need to know what the vacuum is at idle with proper timing (or have a VERY good ear for it)
Your harmonic balancer won't have any numbers on it if it is stock (other than part/casting numbers). The tab you have with the numbers are what you go by, the balancer had a groove on it that is aligned with the proper number on the tab using a timing light.

 

I had the timing set off the tab right now so i know it is advanced over 12 degres and the car is running awesome when it is in park or neatral the problem is as soon as i put it in to reverse drive 2 or 1. Are you saying to put the car in gear and adjust the timing that way?

 

are you sure the vacuum and mechanical advances are working? where are you getting vacuum from?

 

My ole Q-jet w/ electric choke in my 87 T/A used to pop and spit gas and smoke outt of the carb over 2500rpm, so I disconnceted the wire thats goes to the computer to your distributor and it idled fine, plug it back in and wouldnt even run.
after timing this car like 60 times I decide to pull the distributor and VIOLA! .. the culprit

turned out it was a bad rotor that mysteriously broke.

could be anything, hope this helps!

 

Well, thats how every GM vehicle I've owned is set. Block the back wheels on BOTH sides, set the parking brake, get the engine up to temp and drop it in gear and hit it with a light and adjust as required.

 

A couple of questions come to mind. You are running a holley, do you have the powervalve blowout protection crap? Have you checked on the carb since the "flamethrower" incident? You are fine with the tab, thats how almost every vehicle I have ever owned has been, you just need to line up the mark on the balancer with the proper point on the tab. The real thing is, it idles OK, but when you rev it it pops, and when you put it in gear it runs kinda poopy. That sounds a lot like some crossed plugwires. I would double check the wires, and then have a friend check them too. Trust me it happens. My brother has been doing engine work for almost 20 years, and he miswired his truck a couple of weeks back, sometimes you just miss it.

 

i had this same thing happen to me... my q-jet decied to become a flamethrower also.. it needs a rebuild.. once i did that.. it ran like it was brand new.. just a thought. a rebuild is never a bad thing on a carb

 

thanks for all the help guys, i dont know any thing about this carb as it came with the car and i never tore it apart. i have a 750 double pumper that i just rebuilt so i think i will through that on there and check my wires change the plugs cause i'm sure there crappy. Does any one know where i should set my base timing at cause the catalyist sticker shows 0 but that is for a computer and i dont have one.

 

Depends on what the engine wants. 6-8 degrees will usually do it.

 

Ok thanks i'll try that and get back to ya. i was in the neibor hood of 12+ and was getting no where.

 

If I'm not mistaken, isn't there a brown wire that you have to unplug in order to set the timing on the car? I know on my 90 RS there is one.
If you don't unplug that wire you can time the motor all you want, but it won't make one bit of difference.

 

He has removed his CC setup, and went with a holley and HEI. No plugs there now

 

duh, my bad. Maybe I should learn to read before I post?