vperalta

Hello MB World Members,

1 have 1993 400 SEL. I'm having a few issues but I think they are all related to a failing or bad ecu MODULE
part# 140 545 6832.

Runs good on some days. but when it acts up this is what happens or a combination

Rough idle , not smooth. TACH moves from 800 RPM to 1500 rpm. When I try to put in REV, engine will shut down.
Other days, I'll ride it with the rough idle, not smooth at light,sounds like it will stall any minute. Once on freeway for 10-15 min,
come to a stop and all is running fine.
Other days, it will start at high idle, 1500 rpm. Put in reverse and engine dies. Will crank but will not start. Let rest for 1 hour then starts.
Also burns gas rich but I can't adjust that.

What been replaced: Fuel pumps (both) and filter, both distribution caps and rotors, new MAS, UPPER and LOWER harnesses,
Spark plug and Spark Plug wires

I am on my SECOND ECU, not sure if the original was bad because car acts the same.


I know there are many out on EBAY but can these modules be reflashed back to factory specs?
Is there a flashing tool that you can buy?
I am assuming that the ECU loses it's setting due to shorts in the vehicle as wires age.

Any help or advise would be greatly appreciated.

Thank You
Vernon

oldsinner111

Check how your throttle body works,some have wires,and plastic gears that go bad.Used computers on ebay.One company that removes governor,and enriches fuel charges $1200.

vperalta

Oldsinner,

Thanks for the advice. I read many of your replies on other threads and enjoy them.

About ECUs...I just want my car to run right and purchase a good ECU, no need for modifications.
Throttle body gears and plastic clips are good.

BTW..how many Crank Shaft sensors does the 4.8L engine have?
I know of 1 by the back by firewall but I hear another in the front but cant find loaction?

Thanks in advance.
Vernon

oldsinner111

4.8,or 4.2? I think one,buy a hella brand,better than bosch.They usally let engine run good cold,then crap out with heat.Heard they like to break off on v8 models.pay someone to change it on my motor a cam sensor will affect idle,sometimes the magnet part need replaced too.

antose9

What about O2 sensors - did you look at that? Just replace them, they are not expensive and can make a heck of a difference

alexanderfoti

Have you checked the wiring loom for insulation breakdown?