Within the past week or 2 my car has started backfiring a little when its cold. Nothing major, just some pops once I start driving around when its cold. Once it warms up, its fine.

Today something else happened...

I feel it most in 4th-6th gear but when I gun it at low RPM's (between 1.5k-2.5k) the car starts hesitating and jerking all over the place. It almost seemed like my tranny mount broke there was so much movement. In 1st and 2nd the car "feels" fine when I drive normally, but it runs like crap WOT. Any advice or suggestions on what it could be?

 

yes! someone with the same problem! lol. mine starting doing it about a week after i put on my headers and true duals. except it pops at wot. but i thought i broke a tranny mount as well, but i looked at it and it looked ok. http://www.fbodycentral.com/forum/sh...threadid=21537 thats a link to the thread. if i find out anything, ill post, and if you dont mind, do the same

chris

 

sound like you have some bad spark plug wires. when they go bad it is usually felt as a miss under a load.mine were shot and they only had 10,000 miles on the car

 

well, if it matters, since were having pretty much the same problem...i changed plugs/wires, and it still does it. ive tightened the clamps that connect the headers to my true duals to make sure there wasnt a leak causign the o2 sensors to dump more fuel, and the problem is still there. im leaning to a coil going out or needing bigger injectors.

 

oh, and as for the shaking at low rpms, check the torque arm bushing. mine is bad, and thats what was cause my vibs at low rpms.

 

If you don't have autotap or efi live you should consider investing. It's difficult to diagnose without some data and replacing parts can get very expensive, time consuming and frustrating. Under load, weak plugs or wires are more likely to misfire, but it would help if you also gave us some background on the work you've done recently.