Help! My 84 is not running! Have a code 51 and more...

[87GN_ponykillr]

Ok, What I have to sum it up... Yesterday we had the 84' on her first "road trip" (left town) it was very hot and she got up to 70 75 mph on 95 when the SES light came on and started the stumbles and power loss. We get the car to the side of the road and pop the hood and hot as hell about sums it up. No boil over just ton of heat upper rad hose was to hot to even get near. We let her cool down a bit then started back up no problem but not running that good. It went about half way back home easy driving then pulled over for another cool off stop. The car did make it back to the house SES light on the whole way. We checked the coolant and had some crud in it (no milkshake) the oil was fine, clean as can be. I'm sure nothing blew in the motor gaskets seem good etc. So today I came back to look into it a bit more after work and started it to back up a bit no problem starting but she was not running right. I put the code scanner on and found nothing the scan tool said all is fine, well far from the truth. So I disconected the battery then reconect and that did not fix the problem. I then try to start, and notta this time I have fuel but no spark, I did get it to run for a few seconds put with the gas down. So time for the paperclip trick.... That came up with a code 51 ; ECU so...... Anyone ever pull a 51???? I'm not even sure what that code can mean? After that I pulled the rear driver side plug and that thing is BLACK fuel feed bad... A very small spot of oil but not covered just smells like a fuel truck. I checked all the basics wires, connections for loose ends or burns but everything is all and well? Any ideas guys? Thanks in advance. -Adam

 

[Boost231]

CODE 51

Trouble Code 51 indicates that the ECM sensed a fault in the PROM.

When the PROM was initially created, a checksum number representing the total of all the cell values was also stored. The ECM uses this checksum as one way to determine if the contents of any cell has changed. A Code 51 causes the ECM to enter Back-Up mode which uses the CALPAK for default sensor values.

The conditions for setting this code are:

power has just been applied to the ECM, and
the calculated checksum does not match the stored checksum.
- or -
the engine was just started, and
either of two specific PROM locations do not contain the expected value. (One location should have 1's in the odd numbered bits and the other has 1's in the even numbered bit positions.)

Typical causes for this code include:

1) Incorrectly installed PROM module
2) Defective PROM module
3) Defective ECM

could be one of three. i have had and ECM go bad. i would try a different chip then swap the ecm.

 

[87GN_ponykillr]

I'm going to change the plugs this week and borrow a good ECM to see if that works. If it is bad should I do the 87' swap? How much is involved in doing that?

 

[Boost231]

87 swap isnt bad. just need an 87 ecm and a MAT wire and sensor. well you dont have to have the MAT wire and sensor but its cheap.

 

[87GN_ponykillr]

87 swap isnt bad. just need an 87 ecm and a MAT wire and sensor. well you dont have to have the MAT wire and sensor but its cheap.

So the short of it..... Could I just plug in a stock 87 ecm I think its dead. I checked all the connections and they were fine it does smell burned. I just want to trouble shoot my problems for now.