I am new to this site, but like it very much.

I was welding the door hinge on my Cherokee and I had got it all back together and I tried to start it; crank over fine but wouldn’t start. Could the electrical current from the welding machine damaged something? This is the only thing I can think of since it was fine up until this point.

 

If you didn't disconnect the battery, the computer was probably toasted...not good.

 

Welding has nothing to do with your problem. Its eather crank sensor or neutral safety switch. Nss can be bypassed by looping the blk wire in the gray harnis on the fire wall near the heater core lines its # 7 I think.

 

Thanks for the replies, I figured out I'm getting power to the plugs: does this helpls any.

 

Hmm, because that makes more sense than running massive amounts of surging voltage through the computer. If you don't disconnect the battery when welding, you risk destroying all those expensive electrical parts in the path of the electrical current.

 

If the computer is toast, will I still get spark to the plugs?

 

I gave it partial throttle and it started, ran smooth, but it won't idle. Do you have any suggestions. Thanks

 

You could've fried any of the electrical parts. If it won't idle, it could be the Idle Air Control, Throttle Position Sensor, or (possibly)MAP Sensor. I would check to see if all of those have voltage going to them.

 

I would check the MAP sensor on the back right of the intake if you look from the front. its that little screw it 2 prong plug sensor I had a canadian 94 do that ran great wouldn't idle. and I've welded everywhere on mine with battery hooked up with no prob. but still a good idea to disconnect I just always forget to.

 

If you have the ground clamp RIGHT next to where you're welding it shouldn't be a problem. If it's anywhere near electrical parts, it's not a good idea. For example, if you ground it at the front and weld in the back, the electricity has to travel through the entire vehicle to get where you're welding meaning that it's passing through all those high price electrical parts in it's path.

 

I had the ground clamp connected to the hinge below where I was welding.

My nephew reminded me today that I did disconnect the neg. terminal before welding.

I need to get a repair manual so I can locate some of the things you guys are suggesting to check.

BTW thanks for the replies.

 

mine had this problem and all i had to do was clean all the corrosion off the terminals and all the connections. also make sure the fuel pump makes that hummmm sound when you turn the key on.