Hot air in need of help!!!

[87GN_ponykillr]

I posted this in the tech area also... I figured maybe some hot air guys might catch it in this section. Thanks guys!


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.

 

[leehatten]

ecm

i have i think
three ecm two unopened

 

[87GN_ponykillr]

Lee, I might need to take you up on one of those. I'm waiting to see if I can borrow one from a local to make sure it is the ECM thats bad. I checked all connections and they were good but the thing does smell burned.

 

[leehatten]

You Can Have It For Free Just Pay Shipping
Im About To Part Out A 84 T Type I Have A Whole Car That I Cant Get The Paperwork For It

 

[87GN_ponykillr]

You Can Have It For Free Just Pay Shipping
Im About To Part Out A 84 T Type I Have A Whole Car That I Cant Get The Paperwork For It

Oh man that would be great Lee!!! Just tell me how much and how you want it. Whats the deal with your 84?

 

[leehatten]

well the 84 i got from a friend he was suppose to give the the tittle for it but he deployed to iraq and i talk to him once but after that i have heard from him the car is complete and runs on lil smoke but has plenty for power. but since i cant regitster it it no use to me just a parts car as for as the ecm its yours i wil have to chec to see how much is shipping tomorrow give ma a zip and how do u want it shipped.

 

[87GN_ponykillr]

Thats a shame! I hate to see a good car get parted but with out the title not much you can do. Thanks again for the ECM!!! You saved the day!! My zip code is 21157 I would guess 2-3 day mail would be fine?

 

[Boost231]

file for abandoned car. you can get a title that way.

 

[87GN_ponykillr]

Any luck Lee?

 

[leehatten]

my friend who gave me the hotair send me an email yesterday and said that he will send me a power of attorney so i can get it tittle

 

[87GN_ponykillr]

Still no luck guys.... Today I changed the plugs and 02 sensor and ECU and still code 51 pops up and she wont run.... Ideas???????????

 

[BRAD_PADGETT]

Code 51- Recheck the install on the main chip on the ECM. Look for bent prongs on the chip which precludes proper contact. If the chip is installed correctly the ECM is dead. This is from the GM shp manuel. If you have an 85 ECM now is the time to upgrade to the 87. Good luck- Brad

 

[87GN_ponykillr]

Code 51- Recheck the install on the main chip on the ECM. Look for bent prongs on the chip which precludes proper contact. If the chip is installed correctly the ECM is dead. This is from the GM shp manuel. If you have an 85 ECM now is the time to upgrade to the 87. Good luck- Brad

Brad,

This is the second ECM that is KNOWN as GOOD what are the odds of haveing two bad ECM's when both were AOK? I had a local guy who is good with ECM's go over the old one and it was fine inside. I guess I will go over the prong connections again tomorrow... Thanks!

 

[BRAD_PADGETT]

Is he orange wire buy the batterry connected? Another thoight. Brad

 

[SloGN]

sounds to me like it's time to upgrade the electrnics to 86-87 style with a 148 ecm. the hot-air ecm's are kinda of a diffrent breed in the gm world as it is. It's acting like something has affected the Prom itself and its running on the calpak. if the injectors are larger than the stock ones this will explain the rich condition the plugs are showing you as the cal-pak is calibrated for the stock sized injectors.

 

[87GN_ponykillr]

Yes the orange wire is connected I just went over all the wires and they are snug. Now.... Could the chip be / go bad???????

 

[BRAD_PADGETT]

Yes- The chip can go bad. Thanks- Brad

 

[87GN_ponykillr]

Thanks Brad... Now I just need to find a good stock chip. You dont happen to have one do you?

 

[BRAD_PADGETT]

When I fried my 85 chip I decided to upgrade the ECM and ignition system. It is easy to do but it does cost more. Eric at Turbotweak can burn you a new 85 chip if you want to stay stock. Good luck- Brad