Broken Torque Converter
 

My S/S car will normally leave with the wheels up about 3 feet. This year, when I let off the transbrake button, the car stumbles out about 3 car lengths, then runs strong to the finish line. MPH is about normal, but et is off .5 seconds. I tried leaning the primary, leaning the secondary, float height adjustment, different rpm. The car responds to the changes, but both mph and et adjust together. The same .5 delay remains. One racer described it as sounding like it stays on the 2 step for awhile after the leave, but I can't see anyway that is possible. Does the broken torque converter idea fit? Any other ideas?

Re: Broken Torque Converter
 

If it's a Q-Jet car, make sure the secondary rods are sealed. Sounds like a spill-over problem. Regards, Danny.

Re: Broken Torque Converter
 

If it drives off like a STREET Car,then runs strong to the finish line, I would definitely change converters. Been there ...Done that.....M.J.

Re: Broken Torque Converter
 

A converter will not cause a stumble. At least I haven't seen one do it in about 35 years or so. It will make one lazy, but not a real stumble.

As Danny said, it sounds a lot like a carburetor problem, both the Q-Jet and the Holley carburetors do it, but for different reasons.

It can also be one of any number of electrical problems, a connection, a loose ground, I've even seen a battery do it because a plate came loose. I've seen an oil filled coil do it, too.

Re: Broken Torque Converter
 

Hold the T brake on or put it in manual 3rd and hold the foot brake, and flash the converter.
If it goes up to near where it should be.. most likely not a converter issue.

Re: Broken Torque Converter
 

A few years ago when we had my wife's stocker we had the same issue. Started stumbling real bad. Changed everything but the MSD two step module. Took the one out of my car problem fixed. Put her's in my car same problem. Just a suggestion if you have one of these modules.

Re: Broken Torque Converter
 

Could be a broken stator support.

Re: Broken Torque Converter
 

Owen ,Not if it stalls up where it should be.

Re: Broken Torque Converter
 

Thank you for the responses, everyone. A couple more pieces of information: The engine is a 400 Chrysler with a Thermoquad. The carb had set for virtually 15 years while I ran a different combination in the car. Last fall, we ran it on Jeff Roell's chassis dyno. I would bring it up to 3000 rpm, then stab it and hold it to 7000. It seemed to run well. I took it to the track and on the first run, it was about a tenth slow in 60 feet, ran hard to about 150 feet from the finish line, and nosed over. The next run, I turned the two step (dial) up from 3400 to 3800. It ran about .3 slow in 60 feet, then ran more strongly to the finish line, and nosed over again. The last run, I put it up to 4400 rpm. It pushed through the beams, ran .3-.4 slow in 60 feet, ran strong again to about 150 feet from the finish line, and broke up a bit.

Over the winter, I raised the float levels and made a few other changes that the small T-Quad liked on the 318. That puts me to where I am today. I can't say that I watched the tach off the line, but I would say that the rpm stays low (3500-4000) before it comes to life. I DID watch the fuel pressure, and it remained steady.

Re: Broken Torque Converter
 

After further review, I would definately change the carb....Been there ..Done that...Lol.!! M.J.