Tools & Fabrication - Welding take out my PCM?

97 trans am in sig...

I had a shop do some welding on my air pump holes in the exhaust manifolds, now they car won't start (well I got it to start ONCE and it died after all of 5-10 seconds and ran real rough). It hasn't left their shop yet. I have no idea if they disconnected the battery while welding but I'm betting they didn't.

I tried a new battery same thing... in fact it only started when I smacked the starter with a hammer.

Could depend on where they hooked the ground cable....

Nope, mufflers shops don't disconnect batteries....TIGs high frequency is what destroys PCMs. I'm sure they MIG'd it. There's a difference. MIG doesn't have high frequency. MIG is what every Joe Blow muffler shop in the country uses.

If ya keep whacking the starter enough maybe you'll break enough magnet matter inside of there to get it to stop turning over at all!

Hitting a starter is NOT the right way to get your car to turn over.

97 trans am in sig...

I had a shop do some welding on my air pump holes in the exhaust manifolds, now they car won't start (well I got it to start ONCE and it died after all of 5-10 seconds and ran real rough). It hasn't left their shop yet. I have no idea if they disconnected the battery while welding but I'm betting they didn't.

I tried a new battery same thing... in fact it only started when I smacked the starter with a hammer.

Well if smacking the starter did it it isnt the pcm, and you most likely need a starter.... Just sayin...

I had a car in my shop once, sat for 3 days, went to start it didnt start, spent about 25 minutes checking wires, then decided well, I'll just see if I hook up a spare starter it might just be bad. Started right up. Just like that, a starter went bad, sitting 3 days, untouched.

Nope, mufflers shops don't disconnect batteries....TIGs high frequency is what destroys PCMs. I'm sure they MIG'd it. There's a difference. MIG doesn't have high frequency. MIG is what every Joe Blow muffler shop in the country uses.

Dont think he specified a muffler shop.

Well if smacking the starter did it it isnt the pcm, and you most likely need a starter.... Just sayin...

I had a car in my shop once, sat for 3 days, went to start it didnt start, spent about 25 minutes checking wires, then decided well, I'll just see if I hook up a spare starter it might just be bad. Started right up. Just like that, a starter went bad, sitting 3 days, untouched.

Well, if it was the starter it should stay running...

check for loose batt or starter cable.

High Frequency from TIG is usually from AC welding. DC only uses it for a split second.

Well, if it was the starter it should stay running...

If you disconnect the battery the car usually will run rough no? It sometimes stalls, unless you pedal it, shut it off and start it again. Well if the starter goes bad and you cant start back up there is a great possibility.. If the pcm was the prob, hitting the starter would not solve it.

If your crank position sensor is bad, or they cut the wire when they were in there, the car would not run at all, but it would crank. Really there are endless possibilies, I would almost bet my life that the pcm isnt fried.

Dont think he specified a muffler shop.

That obviously went over your head. The relationship was welding hurts computers??? No, if it did every muffler shop in the country would be disconnecting battery/removing pcms before welding or going out of business from not doing that. AND, he said welding to a manifold which would lead me to believe MIG welding which is the same as muffler shops. I threw in the reference for TIG as clarification and for an "in case".

So what were you saying? :eyes:

That obviously went over your head. The relationship was welding hurts computers??? No, if it did every muffler shop in the country would be disconnecting battery/removing pcms before welding or going out of business from not doing that. AND, he said welding to a manifold which would lead me to believe MIG welding which is the same as muffler shops. I threw in the reference for TIG as clarification and for an "in case".

So what were you saying? :eyes:

No, it didnt, and maybe you shouldnt assume anything. :bang: Since when did you become a moderator anyway:eyes::bs:.....

Most muffler shops us mig guns as stated above. I am unsure if they dissconnect the battery or put the ground close to the area where they were welding. But those are both 2 very good rules to obey. Everytime i do any sort of welding on a car. I always dissconnect the battery and leave the ground on what im welding.

a good welding/exhaust/whatever shop should be using a battery surge protector when welding on the car... they are a simple, relateively cheap tool that you hook up to the cars 12v and ground and you get an idiot light that says it's good

This is not the first time i have come across this .We have had all kind of car come in with this after having welding jobs on there cars .ECU'S DO NOT LIKE ANY WELDER 'S

You know you need a starter so start there. Are you getting any codes?