hotshot0602

hey i have an 01 gt 5 speed all stock except for k&n. i recently had a problem with bad hesitation when accelerating. i changed the plugs and the car ran great for 3-4 days. now when the car is cold it shakes real bad at lower rpm's and when the engine is revved from idle it hesitates to rev up and it shakes. the past couple of days this has been happenening when the car is warm as well the iac was changed a few weeks ago so im pretty sure its not that. also the car was ran for codes and nothing came up. any ideas?

tbirdscwd

Maybe a bad COP? Sounds like you have some sort of misfire.

Also, have you checked for vacuum leaks?

hotshot0602

No I have not checked for vacuum leaks yet, I will go do that now. As for it possibly being a misfire. I will take the car to the same friend who ran the codes on tuesday since that is what he said. I was just fishing around for any other ideas on what it could be. Thanks

Obsequious1

Maybe coil over plugs, maybe MAF moisture. I clean my MAF meter with a little starting fluid and use contact grease on the wire harness. That solved my problem once.

ottos

hotshot, here is what i did for my hesitation problems, maybe you can try it.

https://mustangforums.com/m_4511996/...tm.htm#4511996

buwaleed

I think a COP going bad would trigger the CEL wouldn't it?

I had the same problem, and just couldn't figure out what was going on, but got it fixed eventually.

Things to check for:

1- Vacuum leaks
2- TPS <--- this was my problem. Check the voltage on it and make sure it's between 0.85 and 1, if off then adjust, If it's broken then replace it

hope this helps

ottos

Btw COPs don't go bad that often. It might seem like it but its usually not the culprit. Just test it, check the resistance. Spark plugs dont even go bad that often but they are easy enought to check.