72 1st gear lagging

[Eric Fairclough]

Hello, I have a 72 454 engine,400 trans,308 gears. When pulling out from a stop it has a lot of torque and then it seems to be slower pickup until it hits second then it has a noticeable power increase. This car is all stock. The previous owner said it was like that since he first got it too and he had it for 15 years. Is this a normal? Thanks in advance. Eric

[Gerry Proctor]

Re: 72 1st gear lagging

"Normal" is relative to how much you tell us about the particulars, Eric. Like: how hard are you accelerating and at what rpm does power seem to drop off?

With a stock '72 LS5, you can fully expect power to start falling off above 4,500 rpm.

Remember, you're not being charged by the word so don't be shy about telling as much as you can, even if you're not sure it's relevant.

[Eric Fairclough]

Re: 72 1st gear lagging

This happens when i accelerate in normal driving (not kicking in the 4 barrel). The power seems to drop off about 1800 rpm. Then when it goes into second gear it has a lot more pickup. When i punch it you can still tell the little lag in 1st but not as much because the 4 barrel kicks. Thanks Eric

[Duke W.]

Re: 72 1st gear lagging

If you're talking about part throttle acceleration, it could possibly be due to leaness as your car has ignition and carb calibration for emission standard achievement. Increasing the main jets a size or two might eliminate the problem.

Duke

[Patrick H.]

Re: 72 1st gear lagging

I'm no expert on the 72 system (vs. my 71) but Eric may have a TCS system similar to my car, whereby vacuum is NOT applied to the distributor in first gear. This would cause the exact problem he's desribing. I haven't driven a 72 in a while, so I can't tell you what/where it occurs. See that little solenoid on the passenger's side of your intake, Eric, for what I'm talking about.

Needless to say, this system is disconnected on my 71, and full vacuum run at all times.

Patrick

[Terry M.]

Re: 72 1st gear lagging *TL*

1972 TCS with M40 allows vacuum to distributor only in direct (third) gear and reverse. If the system is functioning properly first and second should be the same as far as vacuum advance is concerned.
It would be worth while to check the system function.