OK guys I need some help here, this is really starting to make me mad. So I recently got the new t56 in and since then I have noticed my car pings quite noticably in 3rd and 4th gear while cruising or going up hill. It also does it during light throttle, but not so noticably. I cannot figure this one out. I have always used premium, so thats not the problem. Could it be a bad tank of gas? I am almost out, so I will fill it up sometime this week to see if it makes a difference. But I have retarded the timing almost to the point of stalling it, and that seemed to help a bit, but it still pings. So I tried richening the mixture screws, but no help there. So by turning down the timing, I had to raise the Idle screw, and now when ever I shut off the car, it has done this previously, just not to any great extent, it diesels and keeps running for 2-3 secs, and just tonight when I just got home, it did that and it gave a very solid sounding thump, which is the first time this has happened. Do you guys have ANY ideas on how to help me? I am almost to the point of taking it to the shop and letting them deal with it. Also I pulled a few of the plugs the other day and they looked like it was running slightly rich, but not badly. One more thing which could be related to this, between 1800 and 2300 rpms, it starts bucking so horribly it almost makes you sick. I was told that this was just because of the cam, but I dont know, since it seems to be getting worse.
IF it helps here all all the cam specs I know of.
302 duration total 536 intake and exhaust lift
If anyone has any ideas I am listening, so dont be afraid to speak up. I dont know if this has anything to do with it, but back when I had the auto tranny and this motor, it shifted around 6500, right after the power dropped off, so thats where I usually shift, and one time instead of third, it was a th350, I accidentally put it into neutral, and it revved past 7k, but only for like half a sec, until i let off the gas. I didnt notice anything bad that had happened, so I thought it was all ok, but could this have something to do with the problem? Sorry for being so long, just trying to give you guys and gals enough info to help me out and trying to be complete. Thanks for all the help in advance
Chris

 

TTT, anyone have any ideas at all????
I just got done putting gas in it, and i think i might have just had a bad tank of gas, it is definately less but still there between 2-3k rpms
Chris

 

Carburated engine? What kind of carb you running, and which/what distributor are you using?

 

sorry, its a Edelbrock 600 CFM performer, and just hei from msd, i cant recall off hand

 

mm...make sure you have selected the correct heat range on the spark plugs, maybe try a hotter plug or something. Do you still have a factory ecm in the car by chance? If this car is a computer controlled carb car originally, it has knock sensors, either one or two, and a ESC module that gets the signal from the knock sensors to have the timing retareded.