Hard to diagnose 5k bogging issue s13

[keegan0103]

89 s13 with a ka24e

Car can be started and driven normally, but at some point during the drive it will start to sputter and bog out at 4 to 5k rpm. USUALLY if I shift at 3k rpm its fine and drivable, however I have had it bog off of a light occasionally.

Motor was rebuilt prior to me buying the car, had about 12k when I got it, has 13k now
Aftermarket gauges include narrowband o2 and oil pressure

When this hesitation happens, the car shows to be running super lean, almost not even on the gauge. Usually if I get off the gas and ease back in, it will clear up (until I hit it again) Now the weird part is if its really bad and is refusing to stop acting up (or if its ever bogging at all), I can cycle the key while still in gear and rolling, and it will clear up, every time.

It will also start randomly acting up while im cruising on the highway, and an ignition cycle will also clear it up temporarily

Things I replaced this weekend as per bogging thread in the s13 section:
2 Mafs
o2
Battery
2 ecus
2 fuel filters
fuel pump
fuel sock
drained and cleaned the gas tank
fuel pressure regulator
cleaned air filter
spark plug wires
spark plugs (gapped at .44)

Ecu only pulls code 41, which is due to the intake air temp sensor missing

Im honestly out of ideas at this point...

[sx moneypit]

First off,welcome to NICO!
On your running problem i would take a real good look at all of your grounds.They can cause all sorts of weird problems.
Also get your IAT sensor hooked up.

[Riedell]

Get the IAT in there, it works with the MAF Sensor which is am important component for the car. On ka24de's, they stopped using an IAT separately in the intake system so they converted to it being in one piece which is part of the MAF sensor.

As far as your bogging out hesitation, one of two things: speed limit governor or MAF. Try going WOT from a start off. If the car bogs or attempts to die out: MAF.

At idle, see if the car revs past 5k RPM's. If not, MAF. Check the voltage and ground on the MAF.

I would even go as far as checking resistance on the injectors (between 11-12 ohms and consistent numbers on all four). Make sure the plugs are clean and connected.

Keep us posted.

[keegan0103]

http://www.youtube.com/watch?v=hC-cue5N ... e=youtu.be

Video if it helps

[moso]

how are the rubber fuel lines on your car? I have seen them collapse internally and stop fuel from flowing.

[keegan0103]

UPDATE:
Well ive had a long weekend diagnosing the car. Finally hooked up a fuel pressure gauge and there it was, I was loosing fuel pressure (it would start to fluctuate, and just dump to 0 randomly). So we assumed wiring harness. Jumped the fuel pump to run straight off of the battery, and it STILL happens.

As far as fuel lines, They appear fine, and I replaced the rear 2 when I dropped the tank, however fronts are untouched.

Who knows which are inlet/outlet on the fuel rail? Maybe somehow the lines are reversed?

[moso]

the fuel system should run Pump - Filter- Fuel Rail - Fuel Pressure Regulator - Fuel return line to tank (as in the regulator is connected to the return not the filter)

[keegan0103]

Thats exactly how my lines are routed. Any way a vac leak can cause this? Jumped the posts on the fuel pump to positive and ground, still didnt help sadly, however I did bump up overall fuel pressure by doing this.