I recently had my speedometer fixed and now my car starts to tug when nearing 55 mph. I read other threads and figured my tc was locking up, I already unplugged it and it's still tugging. I have 350 TBI with a 700r4

 

Iunno about "tug"; not a description that means anything to me.

However if what you mean is that the car seems to reach a plateau and just can't accelerate any further, and feels like it's surging or running only in bursts, then that's usually fuel related.

Try a new fuel filter.

 

Both fuel filter and pump were replaced 3 weeks ago but it could be a faulty pump. As far the "tug" the car won't accelerate past 55 mph and feels like it's running out of fuel. I'll change the filter and hopefully I don't have to drop the tank.

 

Yes, it could, at that.

Problem with TBI is, it's tough to measure the fuel pressure. Which of course you would want to do, WHILE IT'S IN THE ACT OF SCREWING UP, i.e. at 55 mph while the car is struggling to run as opposed to sitting idling in the driveway w the hood up. Can be done of course, just not real eeeezy.

Might also want to try tearing down the injectors and soaking em in lacquer thinner overnight, and putting em back together w new paper & rubber. Might or might not "fix" it but sure can't hurt, and it's cheeeeeep & eeeeeeezy, and most of em seem to usually need it anyway.

 

I'm going to replace my fuel pump relay (have a few laying around) and the filter today, if that doesn't fix it I'll park it for the night and pull the injectors.