If I am WOT and get above 4500 it starts to kinda feel like 2-3 cylenders are not fireing right. If I slowly bring and hold the RPMs in first at 4500-5000 it starts to pop out the exhaust.

Ive been trying to get ideas on what all I should be looking for here. The car is carberated. Recently all that has happend was I replaced a lifter, as I thought it was bad (wasnt) replaced pushrods, thought they might be bent plus they were stock. Went one stage rich on secondary side, one step lean in cruise, and .5 rich in power mode on the primary side. Drove with this mixture before I tore into the valvetrain and it was fine. It has been getting colder.

Obviously the distributer was moved. I had marked everything, and lined it back up, but couldnt find the timing light, so Im not sure if timing is spot on or not. I have turned the distributer an easy 25-30 degrees retarted to make sure it wasnt detonating up top causing the problem. I checked the plugs, and they look ok, besides a red tint to the porsoline.

Could it be that the plugs are causing a miss fire. They only have 3kmiles on them. The plug wires have maybe 500miles on them, and pass the dark time night test, and have a 1/4 of clearence between themselfs and anything metal. Everything was fine until I messed with the rockers/lifter. I have reran valve lash a few times, op temp, running, back off until ticks, tighten until ticking stops, then +1/2 turn.

 

In the order that i'd go over this problem:

1) Verify timing at 3000RPM with light. Use timing tape, or a dialback. Maybe try a run without the vacuum advance hooked up. Probably won't tell you anything, but it's an easy test.


2) Check plugs after a WOT run. Or after a few. Put in a new set of plugs for holes #3/4, and check those. Nice new clean plugs tell the most truthful tale. I like champion brand spark plugs as far as reading goes. $3 for a pair, hard to beat.

3) If hitting those two points to comforting thoroughness don't help (did that make sense?), then i'd verify the timing tab is matching the balancer. '87 firebirds didn't have carbed V-8's stock, so there's a chance eh?

Popping out the exhaust sometimes means you're lean, sometimes means too much timing. In a more direct way of saying it- too hot in the combustion chamber, (lean or too much timing does that). So after popping, you might have ash white plugs. If you know you've got the timing right, then it's mixture. Simple as that. (You wish right? )

 

 

Ill give it a shot.

Yep I know they didnt come stock with carbed V-8s. I did the swap

It has a fluiddampener with the correct pointer degreed, and the balancer has -10 - 50 timing marks on it, so its pretty easy to set the timing. Just wish I could find the dang light, oh well there goes another $35. Ill double check the timing hopefully tonight, and maybe pick up some plugs, change them, and get in some WOT passes through second and then check them.

There isnt a possiblity that its a groud or electricle problem is there? Last night at the track, I had my headlights off, at the line, when the bulbs started to light, I fliped them on, well the car died. I started it right back up, but when I was going through first, the lights would flicker inside. Im going to double check my power to the distributer, and double check the engine/chassy grounds as well.

Thanks for the tip on it being too hot in the chamber, thats kinda what I was wanting to know I really have a direction to go in now.

 

yeah im having the SAME problem that you are haave. mine pops after i let off the gas tho and anywhere above 4k rpm it wont accel. noting just no power at all... i have the 3.1l v6