96CK
Newbie
Alright, here we go.....
**Edit #2 - Solved**
So, I got to reading and read a post that reminded me of something. Keep it simple stupid.......
I went back under the hood with a spot flashlight and started looking around.
I immediately found a vacuum line (one of the small, like 1/4" hard plastic ones) broken. I fixed that.
I took off the whole intake assy to get a better look around at connectors, hoses, etc.
I noticed that the top connector for the spider injection from my MPFI swap didn't look to be 100% seated, I took it back off, ensured it was 100% in place.
Took off the MAF, inspected it and corresponding connections, nothing seemed amiss.
I did notice that where the intake seats against the throttle body, the rubber seal seemed to be a little wonky, I fixed the wonk and put it on nice and secure.
All. Codes. Gone.
My assumption is either
A - the fuel harness wasn't connected 100% or making intermittent contact, enough to throw fuel off.
B - The gap where the intake seats against the throttle body was creating a lean running condition (more air than the MAF said was there) causing everyone to read "wrong" (O2, MAF, TPS) they couldn't make sense of the extra air.
Moral of the story, sometimes you need to start at the basics. Close the book, manuals, procedures and start looking around.
**EDIT** (Forgot to put the dang truck information here)
1996 GMC Z71 with the 5.7
Soooo, truck was spitting and sputtering, hard starts, fuel pressure leakdown (immediately), etc, etc.
After some going back and forth, I swapped out the SFI to the MPFI - truck ran great! Fuel pressure leakdown went away, immediate start, ran good (enough).
Oh, it's worth nothing my fuel pressure is still at about 55psi, probably fuel pump at this point, maybe......
Now, fast forward about a week and she fell flat on her face going into work yesterday (plus side, work from home day)
Just got back from the parts house to get my codes pulled -
P0102 - "MASS OR VOLUME AIR FLOW A CIRCUIT LOW INPUT"
P0122 - "THROTTLE / PEDAL POSITION SENSOR A CIRCUIT LOW INPUT"
P0175 - "BANK 2 SYSTEM TOO RICH"
P0300 - "RANDOM MULTIPLE MISFIRE DETECTED"
P1122 - "THROTTLE POSITION SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE"
P1153 - "HEATED OXYGEN SENSOR CIRCUIT INSUFFICIENT ACTIVITY BANK 2 SENSOR 1"
P1351 - "IGNITION CONTROL CIRCUIT HIGH VOLTAGE"
P1380 - "ELECTRONIC BRAKE CONTROL MODULE DIAGNOSTIC TROUBLE CODE ROUGH ROAD DATA UNUSABLE"
So, my thoughts are as follows - P1380 - That's it's own isolated problem, I'll do some digging into that one on my own (unless someone has thoughts on that)
But, I feel that all the other codes have to do with each other and could possibly be being caused by 1 maybe 2 failures. But damn, where do I begin with this one!
I feel like the O2 sensors could cause everything else, but also feel that everything else could cause the O2 sensor codes.
It seems that the TPS might effect them all in some way, but so would the MAF.
I really don't just want to toss parts at the ol girl, she's had enough....... But, if I have to buy a big ol bucket of parts, I suppose I will.....
**Edit #2 - Solved**
So, I got to reading and read a post that reminded me of something. Keep it simple stupid.......
I went back under the hood with a spot flashlight and started looking around.
I immediately found a vacuum line (one of the small, like 1/4" hard plastic ones) broken. I fixed that.
I took off the whole intake assy to get a better look around at connectors, hoses, etc.
I noticed that the top connector for the spider injection from my MPFI swap didn't look to be 100% seated, I took it back off, ensured it was 100% in place.
Took off the MAF, inspected it and corresponding connections, nothing seemed amiss.
I did notice that where the intake seats against the throttle body, the rubber seal seemed to be a little wonky, I fixed the wonk and put it on nice and secure.
All. Codes. Gone.
My assumption is either
A - the fuel harness wasn't connected 100% or making intermittent contact, enough to throw fuel off.
B - The gap where the intake seats against the throttle body was creating a lean running condition (more air than the MAF said was there) causing everyone to read "wrong" (O2, MAF, TPS) they couldn't make sense of the extra air.
Moral of the story, sometimes you need to start at the basics. Close the book, manuals, procedures and start looking around.
**EDIT** (Forgot to put the dang truck information here)
1996 GMC Z71 with the 5.7
Soooo, truck was spitting and sputtering, hard starts, fuel pressure leakdown (immediately), etc, etc.
After some going back and forth, I swapped out the SFI to the MPFI - truck ran great! Fuel pressure leakdown went away, immediate start, ran good (enough).
Oh, it's worth nothing my fuel pressure is still at about 55psi, probably fuel pump at this point, maybe......
Now, fast forward about a week and she fell flat on her face going into work yesterday (plus side, work from home day)
Just got back from the parts house to get my codes pulled -
P0102 - "MASS OR VOLUME AIR FLOW A CIRCUIT LOW INPUT"
P0122 - "THROTTLE / PEDAL POSITION SENSOR A CIRCUIT LOW INPUT"
P0175 - "BANK 2 SYSTEM TOO RICH"
P0300 - "RANDOM MULTIPLE MISFIRE DETECTED"
P1122 - "THROTTLE POSITION SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE"
P1153 - "HEATED OXYGEN SENSOR CIRCUIT INSUFFICIENT ACTIVITY BANK 2 SENSOR 1"
P1351 - "IGNITION CONTROL CIRCUIT HIGH VOLTAGE"
P1380 - "ELECTRONIC BRAKE CONTROL MODULE DIAGNOSTIC TROUBLE CODE ROUGH ROAD DATA UNUSABLE"
So, my thoughts are as follows - P1380 - That's it's own isolated problem, I'll do some digging into that one on my own (unless someone has thoughts on that)
But, I feel that all the other codes have to do with each other and could possibly be being caused by 1 maybe 2 failures. But damn, where do I begin with this one!
I feel like the O2 sensors could cause everything else, but also feel that everything else could cause the O2 sensor codes.
It seems that the TPS might effect them all in some way, but so would the MAF.
I really don't just want to toss parts at the ol girl, she's had enough....... But, if I have to buy a big ol bucket of parts, I suppose I will.....
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