Then

Ok so I searched for a few hours and didnt find what I needed. I bought my 86 Firebird with a 305 a few weeks ago and had some issues overheating (I made it 200 yards from the guys house), and it was running rich. Did some work at a gas station to make it home, but on the way sometimes it would just act up and start missing and sputtering. You could push in the clutch rev it up and it would run fine for a little while before the problem came back. Tuned with the carb which is a holley 4 barrel with electric choke and vacum secondaries, changed the oil, flushed the radiator and block, got AC delco rapid fire plugs, new wires, MSD Cap and rotor button, new front main seal, thought I might have everything fixed (besides the running rich) so I decided to drive it to college (46 miles away) encountered the same problem with missing and sputtering but not near as often, got to school and decided to work on the carb in shop tore it down put new gaskets in and primary diaphram, etc. found out the secondary diaphram was collapsed but no one around had one in stock and I needed a way home so I threw it back together. was going up a hill not far from the college and the missing was worse than ever, so bad that the jerking it caused broke my transmission mount. I gave up and drove back to the college and bummed a ride home.


Now

I tore into the motor after noticing the play there was in the distributor thought it could be the distributor gear or cam gear. So I tore into the motor was very surprised. Flat top pistons, 305 HO heads, COMP Cams High Energy Camshafts (COMP Cams 12-210-2). Put in a new distributor and cam, Aluminum intake, valve stem seals.

My Question

If none of this has solved my problem then WTF IS WRONG!?

 

Bump

 

Vacuum lines?

ECM/Computer if you have it?

Maybe someone else can chime in but I know there is a way of tuning the carb or setting the timing with the coil unplugged but I can't remember if it was HEI or non-HEI or both.

Overheating - do you have the air dam below the car? No air dam = overheating.

 

According to your info you never replaced the secondary diaphragm correct?

If that's the case then you need to replace it and it should help the misfiring and "jerking".

When you rev it up the problem goes away?

It's only at a low load setting in which the jerking occurs?

 

I assume you didn't change the thermostat.

How long had it been running before you left the guy's house?

Collapsed? They look kind of funny because they have to move vertically and the area changes with vertical movement, but as long as it is pliable and doesn't have holes in it, it'll be fine.

'85-'86 305's had flat top pistons stock.
No such thing. All '82-'86 f-body 305's got the same 416 castings.

What type/brand/model?

How are you setting the timing?

 

Ok I appreciate everyones input. I got the car home last night wasn't very fun. Could not get that Holley to do anything at all so I'm currently borrowing a Eldebrock,

Absolutely no power at all and it dont sound right, pretty sure I'm not firing on all cylinders

No I dont think I got an air dam but I didn't have a single problem with overheating.
the front of The Radiator had a good .5"-1" of cut grass covering it so after cleaning that off no problem, and yes I put a new thermostat in it

Distributor is just a stock GM HEI with vacum advance

I know the crank and cam are in time together, I think my motor may have be turned a lil while putting the crank pulley back on so I could have possibly put the distributor back in off by a tooth but I dont think so

I'm gonna make sure I'm getting a spark at all the cylinders if I am then I guess its either ignition timing or some of my exhaust valves may not be closing all the way, so I will do a compression test

 

Timing was off by alot so I'm firing on all cylinders, cant get my temp gauge to work so... idk what to do

 

Tim is probably going to kick me for this, but you need a "Holley" that looks like this:

 

That's a funny looking "Holley"! Kinda reminds me of the time I saw a freind of mine in his 1966 Porsche, a decent car but showing a little age and wear. "Nice car" I told him. "Thanks", he said. I say. "I've never seen a VolksWagon like that before!" I can't print his reply.

 

you can buy a cheap temp gauge at almost any auto parts store, i think the brand is sun something, anyways they are like 16 bucks, i have one in my car now.

 

Just in case anyone was wondering. I got it running still need to tweak a lil on the carb and valves and maybe timing slightly but right now it will roast a tire plenty good through 2nd and lay you back in third. Got my temp gauge working wasnt working due to sheer stupidity on my part but anyway thanks to all

 

Why would I kick you for that? It's my favorite street performance carb!

I haven't kept up with this thread, but sounds like you've worked through your issues.