I have a car problem, obviously. Whenever I'm going say 45 mph or less, let off the pedal, and then press the gas down about half way, my car shakes violently until i let off the gas, or punch it to the floor causing it to downshift. Please help me!
Thanks

btw, how do you set the timing on an enging w/o timing marks?
thanks again

 

Is it only under those conditions of lifting the foot off the gasm then depressing it 1/2 way again under 45 mph?

Timing cannot be set w/o a timing tab. Well, it can be set by ear, but to accuratly set it you need a tab or some form of TDC indicator with marks showing BTDC.

 

pretty much just accelerating, letting off the gas, and then pressing on it again. It's horrible going behind a semi on the highway. speed up, coast, speed up, shake horribly

yeah thats what i thought, i was just hoping for some new way none of us knew yet to set the timing. we've been trying to do it by ear but so far we're unsuccessful

 

When you nail it, does the engine make a sound that sounds like bits of gravel being shaken in a glass jar? If it does, then the engine is knocking, and your timing is off.

 

does it shake when its in park and u give it the gas? if it is u have a cylinder missing

 

What motor do you have and how do you not have the timining tab? Ya sure it's not painted over or something? I assume you have an automatic? And does it only do this while actually moving or will it also do it parked? (If you test that, don't have your foot on the brake if you got an auto=bye bye tranny). My first guess would be you're being robbed of combustion, air or fuel. How's your gas mileage? Horrible below normal standards?

Another thing it could be, if it only happens at that speed, might be your cat. But I'm almost sure this is al related to timing.

 

We don't have to worry about this problem anymore. I pulled the engine about 2 months ago. I'm in the process of "restoring." I cleaned out everything from under the hood, fixed a rust hole and i'm currently waiting on money for paint. The car is white but I'm going to get it painted candy apple red so I'm painting under the hood before dropping a 327 with 2.02 double hump heads in it in place of that crap 305.