Heater core replaced, now wTH is going on..

[KyngofPop]

Had the heater core replaced on my 94 MTX yesterday and now the danged car won't run right. It has a hard time starting and when it starts the rpms automatically shoot up to around 2k then slowly come down. The check engine light comes right on, and the cooling fan comes right on. While idling if I push the gas pedal the car bogs and starts misfiring and popping thru the intake.

The car never did any of this before, and was actually in fantastic shape with ALL maintenance up to date.

Tried pulling the codes but I couldn't get the computer to blink off any codes at all. When I used the paperclip method the only thing that happened was the engine light itself going off?

What the **** could this mechanic have done to cause this by replacing a heatercore? I've checked everything underhood and there's nothing appearingly disconnected.

Between work and school I personally haven't much time to do any wrenching on the car and for that reason is the ONLY I let another person lay hands on her. He and I are gonna go thru it Wednesday when I have a small window of 2 hours in my schedule to check whats going on. Please help with some suggestions.

For the record the heat at least blows warm without fogging up my windshield...mad:

 

[AREA 91]

Was the battery disconnected before any work was done?
He may have fried the computer.

 

[KyngofPop]

He just sent me a text stating that disconnecting the battery was the first thing that he did.

 

[Sarge1400]

Does the car have an aftermarket chip in it?

 

[Irish Pride]

Was it running like this when you picked it up? I would have left it there and told them to fix it. They know how it was running when you dropped it off.

 

[sperold]

I would check the far side to the engine at the cowl (where the heater hoses are). Especially the ground wire octupus on the cowl.
Is there any antifreeze in the far side plug wells (left over from slicing the hoses off and tipping the core to get it out.
Sounds extreme, but as a last resort, you may have to lift the intake out of there to get a real good look at the stuff in that zone, but last resort if nothing else makes an improvement.
Your spout connector is back there, make sure the jumper is still installed, and pull it out to see if it changes anything.

 

[KyngofPop]

@Sarge no aftermarket computer. Chad it was a side job by one of the guys at the shop who used their facilities afterhours. He's gonna go thru it on Wednesday, I'm just weary of letting him tough it at all now...

 

[rubydist]

good chance the pcm is not connected properly or not grounded properly.

disconnect the big connector at the pcm, check all pins to make sure none are pushed back, and reinstall carefully. then double-check grounds in that area.

 

[jelloslug]

Check the vacuum lines and other things in the area where the work was done.

 

[KyngofPop]

Checked everything and it's looking to me like the computer is *****'d. Idk, it's really making me not want the car anymore after all of these years.