cannot run a KOER test on my efi

[marty]

ok so i have been trying to figure out why my engine does not run well upon cold start but i also am having another problem on and off. i am getting a solid check engine light even after the engine is warm. sometimes it goes out quick sometimes it stays on for 10 plus minutes. what it is code 66 vaf/mass air flow sensor fault below minimum voltage. i have tested the sensor and it comes back as saying it's good. i have days where i can run this thing for 25 plus miles on the highway and it runs great come home go back out 15 minutes later and boom light comes on for either a few seconds or stays on for a length of time. but now comes the other issue which is i can run a koeo test come up with codes clear them and then run the same test and get the ususal codes 67,81,82,85,84, and then code 11 system pass which you need to get to run a koer test. when i run that test the engine sucks in some air through the mass air and you can hear the engine rpm change up and down a bit but it never lets me see any codes or such. i have even tried doing a cylinder balance test and it does the same never comes up with the results. these test are being done with 2 different scanners also so it's not the scanners. i have tested the dlc plug as per the test in the snap-on scanner book and it comes up good. this is driving me crazy. i have checked grounds on the rjm harness also checked power cannot seem to find anything. anyone have any insight to help a brother out before i roll this thing out on the highway and light a match. i am at wits end here. any help would be greatly appreciated.

 

[Viperwolf1]

What harness and ecu is it and how is ecu pin #30 wired?

 

[ransil]

How is the RJM harness grounded??

sheet metal screws make shitty grounds.

I will second the pin 30..also what computer do you have.

 

[marty]

rjm harness grounded at the back of the aluminum cylinder head and a heavy ground from the block to the battery. also have a ground wire i added from the radiator harness to the battery for the body. eec is a a9l. and i tried another and the same thing happens. what is pin 30 wire is that the small purple wire that they tell you to wire to start only signal on the starter solenoid.

 

[Viperwolf1]

The RJM harness has a selectable plug for wiring pin #30. It's the auto/manual plug. You need to plug it into the manual configuration with your manual ecu. Actual transmission type does not matter, ecu type does.

 

[marty]

ok so i went out to check the large red wire which is exactly where they tell you in the rjm instructions on the starter solenoid heavy battery terminal. the small purple is on the smaller terminal along with the factory harness wire colored red with a blue tracer which is only hot when cranked i checked it with a volt meter. there is not much more to hook up on the harness that does not have a plug on it. give me a little more insight on pin 30. like what color and where it goes or what it does.

 

[Viperwolf1]

ok so i went out to check the large red wire which is exactly where they tell you in the rjm instructions on the starter solenoid heavy battery terminal. the small purple is on the smaller terminal along with the factory harness wire colored red with a blue tracer which is only hot when cranked i checked it with a volt meter. there is not much more to hook up on the harness that does not have a plug on it. give me a little more insight on pin 30. like what color and where it goes or what it does.

#5 in this diagram

 

[marty]

The RJM harness has a selectable plug for wiring pin #30. It's the auto/manual plug. You need to plug it into the manual configuration with your manual ecu. Actual transmission type does not matter, ecu type does.

ok so now i understand and cannot believe i missed this when i put this all in. does this wire need to always stay hooked up or is a one time deal. the instructions do not say whether or not.

 

[Viperwolf1]

They need to stay hooked up. Only change it if you install an auto type (A9P, etc) ecu.

 

[marty]

alright i feel like a total ass for missing that. is this what could be causing all my issues with cold start and the mass air issue. and i guess the wires do stay together.

 

[Viperwolf1]

Check it and see. It'll definitely cause the 67 code and the ability to runs tests.

 

[marty]

ok you where indeed correct. it does the tests now. i will now see how it runs when it is cold started. geez if that was it i will be extatic. will this make it high idle now when it's cold. it never seem to do that so maybe this was part of that circuit. i will greatly appreciate it if this all works out. i owe you one big time.

 

[Viperwolf1]

Don't know about the idle speed. You'll have to see. Please let us know.

 

[marty]

will do for sure.

 

[marty]

viperwolf and ransil i owe you guys big time. my problems seemed to be solved. my truck starts and runs like a new car when cold. that is amazing. i can drive off now and no farting or backfiring through the intake. i cannot believe i drove it this way for a few months now and i feel like a dumbass i missed it in the instructions no less it was right in front of me when i hooked up the scanners duh. it seems to make a difference in driveability too but that could just be me who knows. thank you guys again so much i am a happy camper.