I just bought an aftermarket ecu.first when i pulled it out of the box,something was rattling imside,sure enough the epromm fell out, so i re-installed it.second after i hooked up the adapter harness and installed the ecu,my car wouldn't run past 4000 rpm's,and a check engine light flashed,i didn't have time to run it because i had to go to work. so i put the stock one back in and it runs fine.so do you think the ecu is fried or not tuned properly,or is the adapter wired wrong.i have no idea and i am frusturated,because i waited 3 1/2 weeks to get it and it doesn't work.any info will work thanks

 

i would send it back if the eprom was completely loose in the casing, then most likely it got a little static to it from rattling around plus it may have scratched a trace on the circuit board. it sounds like the ecu is running in limp home mode. trust me send it back

 

Did you put the eprom in backwards?

There's a groove at one side of the chip which should match the socket and/or point towards where the harness plugs into the ECU...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HardLowrdRanger &raquo;</TD></TR><TR><TD CLASS="quote">Did you put the eprom in backwards?

There's a groove at one side of the chip which should match the socket and/or point towards where the harness plugs into the ECU...</TD></TR></TABLE>


ditto...

here's an image to help show which way the eprom should go:

 

If you're in limp mode it means it isnt reading the Eprom properly, make sure j1 is jumped otherwise it may see the Eprom but not load it, thereby going into limp mode.

 

ok,well what is j1.plus i sent the ecu back i'll get a new one next friday.but i'd like to know just in case

thanks