Running rich

[tandangerranger]

I hust started having issues with my 94 the other day. When i let off the gas the engine stalls, but it will runs erratically if I keep on the gas with black smoke from the exhaust. I changed the fuel pressure regulator, just assuming it was the problem but no help. So I pulled codes and this is what I came up with.

117 - temp circuit below min. voltage indecates a45 deg F
122 - throttle position sensor below min. voltage
112 - intake air temp. sensor circuit grounded above 245 deg. F
513 - internal voltage failure in PCM
565 - canister purge circuit failure
556 - primary fuel pump circuit failure

I am assuming it is the pcm since all the others are not likely to fail at once. I have already checked all the wiring about a million times. If anyone has any suggestions please help, I need my danger ranger.

 

[sholzy]

Did you check your grounds?

 

[feellnfroggy]

Unplug the MAF then replace it. I will almost guaruntee this is the fix. Mine did this, Both of them did.

 

[tandangerranger]

I have checked all the grounds and I did pull off the MAF and clean it. Are you saying I should get a new MAF? I am thinking of putting in a different PCM that I have. It is not the right one but if it makes a difference then I know it is the computer. I had it in the truck before and I know it will run with it.

 

[kimcrwbr1]

Fix the lowest number first when working on codes one sensor can throw multiple codes. Clean/replace the IAT first and erase the memory and reset the computer. Once you get that to clear then work on the next always erase the memory and reset the computer by disconnecting the batt for 1/2 an hour then run it at least 20 minutes at medium speed to set the new values. Then run the codes again while the engine is up to temp to confirm the repair then work on the next one. Did you pull the grounds apart and sand them metal to metal.

 

[tandangerranger]

I have not sanded down all the grounds, but I will do it this morning when I get off work. I will also clean the IAT and reset the computer. I will let you know if it works. Thanks for the help.

 

[tandangerranger]

Well, I cleaned all the grounds and reset the computer. I could not find an IAT sensor on my truck. The book says my truck is equiped with one, but there is nothing on the intake tube except a MAF by the box. So after reseting the computer it was still running the same. I then decided to put the other PCM that I had in the truck and now it works great. I just have to get the right PCM for the truck but this one will do for now. Thanks for all the help.