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Thanks in Advance to any help or opinions given resolve this issue.
First I have a 99 corvette 5.7 with ported stage 2 Tsp heads
running about 10.8 cr with a 227/234 .600 cam
Upgraded my ls6 intake to the atomic msd and a nick williams 103mm dbw
Second, I'm getting the p0107 code
I have replaced the MAP with ac delco brand
After removing the intake like 8x literally trying to resolve this issue
I finally extended map sensor wires so i could mount the map sensor at the front of the intake
Next I have tested the plug am getting the .5v on org/blk wire
There green wire
Then gray faded wire
However when i perform a continuity test it buzz between the gray/orange wire
I'm thinking the gray and green wire is flip because if the gray wire is ground does it need to be in the middle?
Or could it be the computer?
I looked it up up online under " 1999 Corvette MAP Sensor Wiring images " and found several different wiring combinations However you will see that most of them show different colored wires --- and on the opposite side of the pigtail the wires are again different colors and don't match
Thank you so much! I pull the intake off and verify my right wiring and everything is consistent with what wiring was so it is what it is I'm thinking that there is an issue with my computer or maybe some vacuum issue someplace else I'm a little dumbfounded at this point.
Last edited by mickfree; Apr 13, 2021 at 10:15 PM.
The Gray wire is your 5 volt reference and you should see this with connector unplugged key on...the Orange/Black is your sensor ground and you should see less than 100 Mv key on with that one and the signal wire is your light Green...the way to check the signal wire is with a scan tool where you can read the MAP sensor voltage...you jump the Gray wire to the light green and you should read 5 volts on the scan tool or connect the connector and you should see roughly 4.5-4.8 volts on the signal wire back probing it key on...you always check for circuit integrity before you start shot gunning parts !!...if you are seeing .5 volts on the Orange/Black that is 500mv...too high !!
Okay I'm thinking I'm understanding you correctly but with the ignition on and the engine off my orange black wire is giving me .5 bolts the gray wire which is on the opposite end gives me nothing and so does the middle wire when I perform a continuity test is buzzing between the orange wire and the gray wire that's on the opposite ends.
You should see less than .1 volt on the orange/black...the gray is your 5 volt reference...you won’t see anything on the light green...it is the signal wire !!..if you do not understand how the circuit is designed you can’t troubleshoot it or test it...why are you performing a continuity test on a power and ground ???...I have NO idea what you mean by its “buzzing” ?????
Thanks for you response. However this is whats happening in my setup. The orange/black is giving me 5 volts. During my whole dilemma my engine light has gone out with the engine running for 20 minutes.. Then I've turned the engine off/on and the engine light comes back on. But if my grey should have the 5 volts then it seem that my volt wires are flipped. Could this probably be a computer issue? Now as far as testing for continuity I was checking on youtube on how to resolve this error by checking the connector to make sure i have voltage. Once again thanks for your input. The " buzz " was from my multimeter that indicates continuity.
I’d find where the original wire harness ends and recheck each of the wires with your DVOM...5 volt ref and sensor ground...if you didn’t have any issues prior to this rewiring job I’d look there !!
Yes I am for some reason now when I was telling you I was getting it on the orange and black which is correct and to your point that's the second part that I'm trying to figure out I got to see where that wire goes I'm assuming down to where the computer is and try to take a reading from there but I haven't gotten to that part yet. The part that I don't get it is suddenly I'm getting the 5 volt reading on the gray wire when all this time it's been coming on the orange and black wire like originally stated I've checked it twice again today and it's still showing up on the gray wire but I'm not getting the for volts that I think I'm supposed to be getting on the signal wire I'm not getting anything on the middle wire.
Last edited by mickfree; Apr 15, 2021 at 08:34 AM.
C5, thanks again for your help!
I'm stlll trying to locate the MAP wires at the "end of the hardness " which I think you mean at the PCM connector,
He is were I am. At the plug Im getting .5v on the orange/blk, 5.06 v on the grey and .05 on the green signal wire with key on engine off. It seem at one point a got a 4.5v reading on the signal wire but after double triple checking I only getting the .05 v. I'm not sure if I'm right but his is what happen. I have stripped back the harness and resoldered the signal wire but still getting the .05 volts. I plan today is to open the fender well can check/clean the connections. I have a downloaded a wiring diagram i just need to figure out which pins are which. Thank for any additional input you give.
I'm finally resolved this issue I basically relocated my net map sensor to the front of the manifold and then I did a continuity test all the way down to the PCM to verify that my wires were good then I discovered I have some tape on my intake poured which was probably a result of me taping up the porch when I pull the manifold off afterwards the engine light turned off and has not come on for over a week so that part is resolved I still need to have the cartoon which I will get done this week but I can feel more power thanks for all your help and input.
P0107 Code After Atomic MSD Intake Intake Install
