Ok so I have my new engine set up and everything pretty close and I have it to where it will start and idle great but I’m having a few problems. When I try to put it in gear it sputters and dies and I can’t keep it running, and not sure if this is related to it but when I hook up the vacuum advance it revs up to like 2700 rpm and will not ever come back down to idle. Help please because I really have no idea what this could be.

 

Vacuum advance? On an '87 Firebird? That sounds like a non-stock arrangement. A lot more information will be necessary to describe the system before meaningful advice can be offered. The stalling on gear engagement is sometimes a lean condition.

 

Is this according to the wavy-pointer "sporty" trim package in the dash? Or is it from an actual instrument of some sort? If it's the dash trim package, have you verified its accuracy against a known-accurate instrument?

 

not sure exactly what you’re talking about but I’m using the same tach that’s always been there and it always worked fine. Also I can hear it rev way up. Not 100% sure the number is accurate but it seems accurate to me based on what it sounds like

 

its a new engine and very far from stock lol, I could tell you everything I’ve put on it if that would help. I’ll try messing with the fuel-air ratio on my carb and see if that makes a difference though.

 

The factory "tach". Or I should say, the factory "tach-shaped object".

They are well and widely known, notorious even, for failing, by reading WWWWWAAAAAAAAAAYYYYYYYY high. I had one in my possession at one time that read 3 times the true engine RPMs. They're never particularly accurate to begin with; the chip's specs is like 5% accuracy or something.

The point in your case being, if you're setting the engine RPMs to, say, 600 on that thing, but the REAL RPMs are, say, 400, then it's no wonder that the engine dies when you put it in gear, and it goes to 300 or whatever.

Another thing to consider is, whatever you have your "timing" set to before you apply the vac adv, and how you set it. Like the factory tach, the "timing" marks are NOTORIOUS for being inaccurate; most especially, when there's a mismatch between timing cover and crank damper (say, stock damper, and aftermarket "krome" timing cover & pointer). They also suffer from the fact that the "mark isn't on the part of the damper that's actually bolted to the crank, but rather, is on the outer inertia ring, which is only loosely associated with the crank by a BLOB OF SPOOOGE. The inertia ring frequently can move around on the damper hub, taking the "mark" with it; making any kind of "number" you pretend to read with a "light", TOTALLY out to lunch.

You might start by advancing the "timing" to the point at which the engine just begins to ping, then backing it off until it stops pinging; and seeing how far that is from wherever you "thought" it should be. That won't necessarily be exactly "right", in fact probably not although it should be somewhat close, but is often a real eye-opener as to how far off the whole "mark" deal is. You may even find that it's retarded SO far now, that it's almost to the point that the engine won't even run if you retard it any further, which would be a clear indication that it's way wrong.

 

so I’m not completely sure about my timing currently but it used to be spitting fireballs out of the carburetor because it was so off lol. But now it starts up and idles perfect until I hook up the vacuum advance. As for the balancer thing, everything on this engine is brand new besides the crank and pistons so I don’t think it’s a balancer thing. I know the vacuum advance is revving it way to just because I can hear it, it sounds like it’s revved wayyyy to high. Honestly I’m not a timing setting expert, currently I’m at about like 10 degrees advanced but I’m not sure if I even set it right because all the videos I watched confused the hell out of me. But the tach always read good for me, at least pretty close just based on how the engine sounded.

 

OK, so did you read about

What happened when you tried

 

I’ll give advancing it a try and see what happens