MPFI problems

[Mrich0908]

SO I already swapped over to mfi few weeks ago.
I dont drive my truck that much . I took a longer drive today. Car stalled on me in a parking lot . Was missing cruising in 3rd at 40mph.
Im getting o2 codes , bank 2 lean . I hooked my scan tool up bank 2 was running extremely lean while bank one was very rich. Cylinder 4 and 6 were miss firing.
I decided to pop of my upper intake to make sure I routed the new mfi correctly . I did .
When I opened it though there was allot of gas like something was leaking . I hooked up the fuel lines , tapped into the fuel pump diagnostic power line ran the system at full pressure for few secs. Nothing was leaking .
Any thoughts? O2s are new. I even had old ones swapped em out they were fine codes still pops up. New distributor gear , cap rotor , plugs , wire have under 10 miles , did the lower intake . Cools fine.
Im not sure what vacuum should be on the sbc l31 but mines -10 at idle. CMD on the distributor is set to a little over 0 but under 1 . Cleaned my Maf , EGR(is there a way to ohm the egr out) . Inspected vacuum lines . Ran propane over the motor with no change in rpm. I dont hear a vacuum leak.
The truck surges at idle also but seems to run better at open loop . I usually pretty good with this stuff but this has me stumped.
I didnt buy the update bracket for the mfi Conversion what does it exactly do?
Edit , im sitting here thinking why would I have fuel polled in the intake but the ECM say Im running lean?

 

[someotherguy]

Probably a vacuum leak (think intake gaskets) - looks lean, so PCM richens up the mixture more than necessary.

The -10 vacuum reading - is that MAP or BARO?

Richard

 

[Mrich0908]

I think its map scan tool shows map , I didnt hear any hissing . I did run propane around the intake with no rpm change. But there was so much fuel in the intake who know.
Its the only gauge I dont have. 10 is what the ecu see , my scan tool sees.
Im readjusting my lifters . Month ago I found the previous owner installed the distributor gear up side down so at this point everything is game. Looks like the motor is used or at least the heads are. I pulled my motor last week to do a rear main seal and noticed grease crayon on the castings on the back of the head were the humps are to identify the cylinder heads. I didnt think they came like that from GM.
I pulled the upper intake and reinstalled it , maybe I made a mistake .
I happen to have a junk gm car with the same coolant temp sensor(the 2 wire for the ecu) and map . I pulled them . If nothing improves I will install each one separately to see if that changes anything.
Valves look good doesn't seem like weak springs , nothing was broke.
EDIT
............
I put it back together . Swapped out the map, egr and cts sensor still doing the same thing. spayed the wires with water there not arcing.
Has to be something stupid.
The o2 do look a little better though. Bank two doesn't show a lean condition at 0mv it fluctuates up and down now. Bank one is still pig rich.
Maybe just because I let the intake sit out in the air to dry over night . May be the valve lash was re adjusted.
Who knows 4-6 are missing terribly though.
I cant find a vacuum leak for the life of me .

 

[Mrich0908]

Im starting to think my ecm is bad or a short. Ecms are 20 bucks on ebay. I I find one from a 97 1500( I have a 97 yukon 1500) do I have to have it re flashed.
This really bad I keep gas washing my oil. No lie I have 15 gallons of oil on my porch.

 

[someotherguy]

Replacing the PCM should be pretty much dead last on your list of suspects, but do what ya like.

Richard

 

[aaronb]

Check the firing order to the cap. Sounds like you have a wire crossed.

 

[Mrich0908]

Nope checked long time ago.
What else besides grounded injector wires or ECM could it be.
Ive bought , cleaned , retimed everything . Valves are good I personally looked at them.
Ive Become so frustrated Ive began throwing parts at it.
Im going to do continuity tests today.

 

[Mrich0908]

I checked my injectors with a probe light. Some of the Positives have grounds going to them . My test light lights up dimly.
I probed were the spider and harness meet on the harness side.
Im going to disconnect the harness from the computer to see If I can isolate the problem.
Does any one have any suggestions. Ive never chased down electrical gremlins before.
Edit... I feel stupid . My arm was touching the air conditioner , thats what was grounding out the circuit.

 

[Mrich0908]

The plugs I was given when I did my tune up last week are wrong. I hate people at auto part chain stores. There so incompetent. They gave me the shorty style sbc plugs.
Gas washed my oil .
I been given the wrong part at least 4 times this year. Every thing from starters , to a vss. I had my whole injector harness ripped apart over this .

 

[aaronb]

That sucks, went through the same the last week and a half with mine. Damn truck wouldnt throw a code. Threw money at stuff it didn't need, ended up being the cam position sensor causing my miss.
Then I get it running and take it out and the transmission isn't shifting right. Find out last night testing fuses, sensors and realized my rear lights aren't working. I'll be replacing the brake light switch tonight.