SiskMan

I recently did a swap to a LQ4 that I built and everything went pretty smooth. Car started right up. Drove it a little to break it in and it had great power. I drove it over 200 miles before today. Now i started it up a little while ago and its really down on power. Took it to the auto parts store and scanned it and it has 10 codes.

PO301 cylinder 1 misfire
P0174 BANK 2 LEAN
P0171 BANK 1 LEAN
PO102 MASS AIR FLOW LOW INPUT
P1637 GENERATOR L TERMINAL CIRCUIT
P0530 AIR CONDITIONING SENSOR A CIRCUIT
P0300 RANDOM MISSFIRE
P0174 BANK 2 LEAN
P0171 BANK 1 LEAN
P0102 MASS OR VOLUME AIR FLOW A LOW INPUT

seems like a lot for just an engine swap. I just replaced the intake gaskets, new map o ring gasket, and i did reconnect the little hose on the back of the intake. The booster hose is good. both pcv hoses on the valve covers are good. it has brand new plugs. and the MAF is not that old. The manager of the parts store let me borrow the scan tool that streams live data, just for the night. He said he will bill my account if I don't return it

What does all this point to? Im stumped. The scan tool says .70 ish on the maf while the map says 10.0 or more always. I don't know what the readings are suppose to be

subeone

iTrader: (5)

you sure you dont have a vacuum leak? id check that first.

SiskMan

i checked all the hoses and even took the intake off and put new gaskets. The FelPro intake gaskets are much thicker and i know they are sealing better than the old ones. new grommet thing on the MAP sensor, and reconnected the little vacuum hose on the back of intake. both valve cover hoses are new and connected. throttle body is tight. booster hose is good and connected. Im stumped. I know it sounds like vacuum from all those lean and MAF codes.

Ill throw it on the vacuum guage tomorrow, then the fuel pressure guage. Maybe crack in intake? doubt it but who knows

subeone

iTrader: (5)

If you're sure the manifold doesn't have any leaks, and the MAF is connected then..
squirt some water in the manifolds, does the water evaporate quickly ?
if they don't, your injectors or plugs arent firing..since you have lean codes, check for injectors functioning.

at the end, verify proper fuel pressure.

Won-Ton

Check your connectors.

SiskMan

Everything has been plugged in from the git go. I erased the codes, drove it around for a while, and scanned again. Nothing. Zero codes. Odd.

It has 18 in/hg at idle and goes up to 20 with even the slightest bump in throttle, up to a certain point of course. Wish i had a smoke machine to rule out vacuum all together though. Fuel pressure was 58 PSI

sreve

iTrader: (3)

Your map 10psi at idle you do not have any vacuum leaks to worry about.
.7 gps on the maf is way low and why it is running lean. The misfires are most likely caused by the lean fuel. Unplug the maf and see if there is a big mprovement.

SiskMan

i guess in the process of trying to find the issue, i fixed it without knowing what the problem turned out to be. cleared all the codes and the car ran great after that for weeks. now starting to tune using HP Tuners