Ive been having a intermiting miss with my 1992 5.2 dakota and it finally threw a check engine light this morning and i did the key trick and found these codes: 12,17, 23, 27, 51. any help would be apreciated on what could be linked between all these codes
Thanks

 

12* Direct battery input to PCM was disconnected within the last 50 key-on cycles (normal)

17* Closed loop temp not reached or engine cold too long

23** Intake air temp sensor signal outside acceptable range

27* Injector control circuit failure

51** Fuel system lean

Fault Codes with * - check engine lamp will not illuminate at all times if this code was recorded
Fault Codes with ** - Checking engine lamp will illuminate when the engine is running if this code was recorded

 

Sounds like you have a bad fuel injector. Not sure about the engine temp. Maybe a failing coolant temp sensor or IAT sensor? Check wiring and test the sensors. Someone else may be able to help more.

Check your wiring to the injectors and test your injectors.

 

Thanks for the explenation of the codes

 

It could be the temperature sensor or it could actually be your thermostat is sticking in the open position. Access to a scan tool would be helpful for more information on what the computer is reading while the engine is running. Good luck!

 

For an update i recently replaced cap, rotor, plugs and wires along with the injector #3 and still have the code 27 for injector #3 failure along with a miss that comes and goes it seems to be more often when the temps are 20*+ but its weird it does it every now and again some days it will miss from the first start and last all day or it just misses for a couple of seconds while crusing down the interstate at 70-80mph. also getting code 51. i will probably replace the 02 sensor and see where that gets me im thinking it might not help because of the injector code.

 

Another possibility that comes to mind, is the possibility you have low fuel pressure. You may have to get a gauge on the fuel rail to find out how high your fuel pressure is. It seems unlikely due to the fact you make it sound like you are only having the miss on one cylinder. Low fuel pressure, whether due to plugged fuel filter, bad regulator, line blockage, or a bad fuel pump would more likely cause a miss on more than one cylinder and would show up the most when you are loading the engine or trying to accelerate hard. An engine basically needs three things to run. It needs an air fuel mixture of 14 parts air to 1 part gasoline, compression of the fuel air mixture, and a spark at the right time to ignite that mixture. There are many factors that can effect it. A fuel injector not atomizing the fuel properly (probably will not trigger a code), fuel not injected in the proper amount (faulty injector), air restriction or dilution due to a vacuum leak or plugged air stream ( may or may not trigger a code), EGR system not functioning properly (should trigger a code), or it could be a weak signal from an oxygen sensor. It could be hard to diagnose without hooking up a scan tool and possibly an exhaust analyzer. Good luck!

 

One thing I forgot to mention. You will need to disconnect the battery for at least 2 minutes to clear your codes, unless you have a scan tool to clear them with. It could be the computer is not resetting after the changes you made, but it should regardless whether the codes have been cleared or not. Maybe someone else with more experience than myself could shed some light on that possibility!

 

I would say a scanning computer is out. its a 92 so its OBDI. also, for the injector problem, looked for a semi-broken wire somewhere along the lines of injector 3. if the problem is intermittent, then maybe the engine vibration is shaking a wire loose. that should solve the miss in that cylinder. now the fuel being lean, is likely from the o2 sensor. if the EGR is bad, it will throw code 32 like mine does. however my EGR has been bad for over 2 years and I've never had any running issues with it. it never misses, never backfires. runs fine. Closed loop temp not reached or engine cold too long means your thermostat is likely gone. may I recommend a 180 degree Hypertech thermostat from hughesengines.com. our motors like to run at 180 degrees a lot more than 195 degrees. and Injector control circuit failure proves more to my point of a broken wire somewhere along the lines of injector 3. I bet if you fix that injector problem, the majority of those codes will disappear. Good hunting!

 

I have a scan tool and I also have a 95 Dakota with a 3.9. I have used my scan tool on my Dakota many times. It does not show the detail that the newer vehicles do, but it can help with streaming data while running down the road during the course of investigating the problem. As far as EGR systems are concerned, I agree that it should generate a code as I stated before, but I have also had EGR valves stick in the open position and cause an intermitent missfire. I also had a problem with my 95 Dakota where I would put the scan tool on it one day and it would show 2 or 3 codes. The next day it would show 2 or 3 different codes. After about a week of seeing codes change, clearing them and different codes come back, I changed the PCM and that cured the problem. The other points you bring up, I agree are valid possibilities.