PROBLEMS after cam swap, please help!!!

My cousin had an E -cam on his 89 coupe and the car ran and idled fine. The engine is stock except for the pullies and exhaust. He decided to buy an f -cam and swapped it in. Ever since the cam change, it won't idle steadily, then it dies. It runs rich because the plugs are all black when we check em. The only thing he did was swap the cam and nothing else. Since then he replaced the plugs, cap and rotor, new o2's, map sensor,tfi module,tried the air meter off my coupe, new tps,new iac,timing is at 14,new egr, and still it runs rich and has an erratic idle.If he floors it, the car runs strong but it wont idle and runs rich. The fuel pump is new and we tried a different fuel rail incase the old pressure regulator went bad.He tried different injectors that are all in good shape. It has no vacuum leaks either cuz we double checked those also.We just about gave up!! It's not the cam because I just installed an f-cam about a month ago and mine runs fine. I had an E- cam before too. Let me know if there is anything else we have overlooked. We are curently pulling codes.. Thanks for any help or advice you can give us.....

proxses said:

When you say you replaced the MAP sensor, that seems slightly odd to me. I wounder if it is currently plugged into a vacuum line. This would cause the computer to think that the incomming air that the MAF is reading is greater in volume than it actually is due to the lower pressure reading, and thus adds too much fuel.
I'd check to see if the MAP is reading open air, or if it is connected to vacuum.
Also, have you sprayed starter fluid or carb cleaner around the intake to see if there is a vacuum leak?
What is your voltage reading on you TPS?
How long is the car able to run before it gets too rich and dies?

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Well yesterday we replaced the injector harness with an extra one we had and tried another upper intake just for the heck of it. To our surprise the car idles fine now, all we have to do is replace the plugs since they were fouled out from running rich. I figure the harness was bad because nothing else seemed to fix the problem.. Thanks for your help....later!!