[steve25]

As I recall what was the 360 hp motor in the GTO was down rated to 345 in the Firebird by means of limiting the secondary throttle opening, but that being the case 345 Hp will not feel like a Turd, nor will even 300 hp.

Oh, and if it has not been posted yet confirm your firing order.

[Stan Weiss]

Originally Posted by Lidpainter

Why is my Firebird such a gutless turd? 1969 Firebird, 400 ( .030 over), M-20, 3:73 rear. Engine has strong, even compression, #62 heads, long branch manifolds, Gardner stock-type exhaust, stock 1969 intake, correct 1969 M/T recalibrated Quadrajet, Summit 2802 cam, 1.65 rockers, DUI HEI with 24 degrees @ 3000, Delco 44R plugs gapped to .050 (as per DUI instructions). Runs cool even in 90 degree weather. Total timing is/has been 32, 34 and 36 degrees while trying to find the sweet spot. Still looking for it. Sadly, it pulls about as hard as the Saginaw 3-speed V6 ’81 Malibu I had as a kid. None of that pushed-into-the-seat power I have had with previous cars. It’s embarrassing. What am I missing? Could this still be some kind of timing/ignition problem? Slipping balancer? Is the quadrajet insufficient? Way too mild a cam? Has Greta Thunberg put a curse on me? I’m stumped.

What is your CR?

A couple of people have asked. So why not do a cranking compression test?

Stan

[NeighborsComplaint]

Cam timing is retarded.

[Lidpainter]

Mystery solved. I picked up a TDC piston stop tool. Seems the balancer has slipped/is bad.
According to the TDC tool, my balancer reference mark is off by about 11 degrees. Top line is original mark, lower line is correct according the the TDC tool. If I’m not mistaken I’ve been running 10-12 degrees retarded.

[grivera]

Excellent news - please update after you swap in a new balancer.

[steve25]

Good news to hear!

That much retard is right on the edge of the motor backfiring when you mash the throttle which would have been a more definitive clue to your issue assuming your firing order was right.

Now get a new balancer and go make some rear tire smoke.

[kyle_blake]

Right on!

[Formulas]

you can go by the new mark and time it presumably correctly and enjoy how it is supposed to run while waiting on new part (sanity check)

[steve25]

You might want to take advantage of this service if your balancer is not cracked in the keyway area.

[GOAT8U2]

Well that could've gone bad if it was 12 degrees advanced, I smoked all 8 cylinders on a fresh engine all because they didn't mark true TDC on the balancer and it was 4 degrees advanced.

[steve25]

Who's they?

In that case how did you even set the initial advance on the motor?

[Formulajones]

That's a very small detail that is commonly never checked.

Easy fix though.

Even with a new balancer I'd still verify the mark and remark new balancer if necessary (usually is) as I find new stuff is even off a couple degrees.

[geeteeohguy]

My gut is telling me the cam timing could be retarded. What does the vacuum gauge say? Where are things at TDC? Have seen timing chains installed off a tooth give the same symptoms. Engines that should run strong run like yours.

[Stan Weiss]

Originally Posted by Lidpainter

Mystery solved. I picked up a TDC piston stop tool. Seems the balancer has slipped/is bad.
According to the TDC tool, my balancer reference mark is off by about 11 degrees. Top line is original mark, lower line is correct according the the TDC tool. If I’m not mistaken I’ve been running 10-12 degrees retarded.

No Updates? All you need to do is advance the timing to see if it fixes the problem.

Stan