1984 Buick Grand National Hot Air Code 42

[Gn.Cal]

Hi Everyone,

First and foremost thank you guys for the help and support.

Also, I will inform that I am a complete noob to these cars so bare with me as I will still have trouble on some of the acronyms.

Ive searched on the forum for guidance on this issue ( Code 42) and I've tried some of the responses and I couldn't pin point it so I decided to start my own thread to see if there is something I'm missing.


I have a 1984 Buick Grand national with 64K miles on it. The car sat for 20 years (1st owner and now I'm the second) and ended up replacing all the essentials ; Water pump, spark plugs, wires, gaskets, standard stuff etc to ensure the car would run well for the time being before doing upgrades.Finally a year passes with no issues and decided the time has come and now I've run into a lot of issues that maybe some of you can help.

These are the modifications to the car that have been done ;

1. Upgraded Stage 1 turbo (Not sure which "turbo" it is, but from work turbochargers)
2.Stainless Steel headers.
3.G-body parts 3" down pipe
4.2.5" pypes exhaust
5.Maf Translator w/3.5 LS1 Maf
6. Scan Master
7.86/87 ECM with T.T Chip ( Burned to all the above specs etc, ECM is from oreillys, not sure brand )
8.86/87 ICM (Ac delco)

Recently, I had a high idle at 3K RPM and the team directed me to a "sticky" throttle. After Some review, I noticed the outside throttle body cable blade was bent and after some adjustments, car ran back to normal. (Set screw was not touching because the blade was bent causing the throttle blade to stay open)
The only code that was displayed was "code 24" which was fixed.

Once fixed, took the car for a drive around, drove great, parked the car and then it rained for 2 weeks.....I didn't cover it since it needs to be repainted and thought it will be fine...once opened I noticed water in the car.

Finally got some time to "clean" the car to enjoy and then.... Code 42...

So here are some things I checked ;
1. EST wire on the ICM - Making contact
2.Cleaned the A/B connectors to the ECM - Looked clean
3.Removed and cleaned the Chip on the ECM -Looked clean
4. Swapped the ESC on the firewall - Stayed the same
5.Checked the firing order on the ICM to ensure it was correct and looked fine(Still unsure if I have the firing order correct)
6.I didn't do the casper adapter for the ICM, I moved the wire to there "correct" spot and checked to confirm it was correct like 20x
7.Did the "pink" wire from the ICM to the Firewall fuse box to D4?

I do want to mention that I noticed since the car is parked in the driveway (will be in the garage soon) and since it rained, I swept my fingers on the carpet floor near the ECM and felt water and seen condensation and I assume that maybe the moisture might of effected the ECM?

Once again, thank you for the help and so sorry for the run on sentences and so much or little information. Trying to detail as much so you guys can picture maybe what was done. I also wanted to mention that I am located in California in the valley and willing to pay someone with the knowledge just to fix it just in case I can't figure it out.

Thanks

 

[Gn.Cal]

To Add on to this that might help, It does smoke a bit from the exhaust. I Did not upgrade the fuel pump and I have the 30 lb injectors.

 

[HotAirWH1]

Is the car running with the code 42 or is it a no start ?

 

[Gn.Cal]

Is the car running with the code 42 or is it a no start ?

running with code 42, but extremely bad.

 

[HotAirWH1]

Have you read through this: --> DTC 42 Diagnosis

 

[Gn.Cal]

Have you read through this: --> DTC 42 Diagnosis

Yes, going to try and see if I can do this. I’m a little st**id when it comes to electrical and using the tools properly. Lol

 

[Gn.Cal]

I want to add that I reset the ECM and started the car, and let it run for 40 mins with no issues. Once I turned it off, and turned it back off, code 42.