Mechman Alt causing my car to jerk (misfire symptoms)

[zoeboi954 0]

i bought the alt like 2 months ago because of it not fitting my car bracket it took a while to get the right bracket. but anyways when i installed my alt i notice my car stated to misfire i thought it was my spark plugs so i took it to my mechanic had he told me it was the alt. when he unplugged the alt the car was perfectly fine and as soon as he plug it back in the jerking began. and it gets worst when theirs a load like a/c radio headlights

why is my alt causing my car too jerk is it a bad alt

watch this video to see

and it does charge 14.4v but when the car jerks it drops 14.0 - 13.7

Edited October 28, 2012 by zoeboi954

[Infinite913 381]

by chance did you double look at the belt to insure that its the same levels for all the pulleys. I just had my astro have almost this same issue and the a/c delete pulley was not sitting right and causing the belt to make noise and cause it to not charge in random spots and then lined that all up and boom no more noise and worked great. Im just throwing out a suggestion hope its that easy for ya.

[edouble101 314]

What is the resting voltage of your battery?

With the alternator plug connected does the belt squeal when you start the car?

[shizzzon 461]

Wel, you definitely have belt squeal so until you fix that, that's possibly the problem.

[zoeboi954 0]

What is the resting voltage of your battery?

With the alternator plug connected does the belt squeal when you start the car?

usually like 13.0 - 12.8

and yes it does

Wel, you definitely have belt squeal so until you fix that, that's possibly the problem.

do you think i need a smaller belt

[pmureika 31]

How thight is the belt? I see it is only going around about a 1/4 of the pulley.

[zoeboi954 0]

by chance did you double look at the belt to insure that its the same levels for all the pulleys. I just had my astro have almost this same issue and the a/c delete pulley was not sitting right and causing the belt to make noise and cause it to not charge in random spots and then lined that all up and boom no more noise and worked great. Im just throwing out a suggestion hope its that easy for ya.

i'm not sure how to do that. the alt is fun when its unplug and it spins great. but when it pluged in thats when it shake sometimes. but it still charges at 14.4 it just drops at jerks

[pmureika 31]

by chance did you double look at the belt to insure that its the same levels for all the pulleys. I just had my astro have almost this same issue and the a/c delete pulley was not sitting right and causing the belt to make noise and cause it to not charge in random spots and then lined that all up and boom no more noise and worked great. Im just throwing out a suggestion hope its that easy for ya.

i'm not sure how to do that. the alt is fun when its unplug and it spins great. but when it pluged in thats when it shake sometimes. but it still charges at 14.4 it just drops at jerks

I think he means are they all lined up straight.

[OuTLaWeD 110]

yeah, def. need more belt wrap. like said before also make sure you have a good belt on there and make sure the belt is proper lengh. a high output alternator is alot harder to turn than your factory alt so depending on the vehicle you may have to figure out a way to get another idler pulley in the vehicle so the belt wraps further around the alternator pulley so you don't get belt slip. if your vehicle has higher mileage on it or is "older" you might also want to change out the belt tensioner so you know that it's putting as much tension on the belt as you can possibly get. just a couple ideas to throw out there

[jonbearsmt 919]

raise your idle.