Engine Swap Help
 

I have a 1997 C230 on which I performed an engine swap. I put everything up, started the car up and it idles fine. But when I accelerate the rpms go up to about 1500 and then drop down and goes back up. The engine keeps osciallting like this until I turn of the car and try again. Again it idles great but when i hit the gas the same thing happens. The car is in park when i do this. I didn't have this problem with the old engine. Could you guys tell me whats wrong and how i could fix it? Thanks

Additional info
 

Also the whole time this is happening the check engine light is on. I called the dealership and they told me its something with the exhaust but they couldn't be sure without a diagnostic test.

why no go on engine swap
 

sounds like the electronic throttle system is in 'limp home' mode. It resets every time you turn off the ignition, but apparently there is a persistent failure in it. Gotta pull the codes--it may be the wiring harness (main) on the ETA harness itself.

After an engine swap triple check conectors.Even the best forget something.
Ground wires and MAF sensor could cause this problem.:)
Good luck
Rich:eek:

thanks olpos you were right