Running Lean - stumped as to why

[CrUZida]

Did some tests today.

Started with pulling the # 2,4,6,8 leads off one at a time, all 4 made a difference, so all injectors are working.

The pulled things apart to get down to the injectors. Noticed that #2 injector was all wet. Started fuel pump and wiggled injector, she leaked. So replaced that with a spare.

Then tested compression on 2,4,6,8 - all were ~ 220-225psi, so no issues there.

Started to put it back together and noticed #8 injector had same symptons to #2. So replaced all 4 with spares.

Put it all back together and took her for a drive. AFR's are much more realistic now, but still not quite what I'd expect them to be given the high fuel pressure.

I think the next step is to get all 8 injectors cleaned and put a stock sized fuel pump in.

[CrUZida]

Swapped the fuel pump out for a new MA70 aftermarket replacement (ie, not a high power one).

Started it up, evrything was looking good with 13:1 at cold start idle.

Took it for a drive, and she's now 18-19:1 on cruise on drivers side bank.
But at WOT I can get it down to 11.5:1 - go figure.

Looks like I need to do some investigating on the drivers fuel rail.

[oldcorollas]

where are the pressure regs?

[CrUZida]

Drivers side rail

[CrUZida]

More updates.

Replaced the drivers side fuel rail with my spare one to test the pressure. Gauge read 48psi static pressure. So probably gauge is a little wrong, but its closer to normal than the 54psi I was getting before. (didn't test with car running as its a prick to do so).

Put it all back together with original rail, ensuring all injectors were carefully placed and not leaking. (Tested for leaks prior to putting intake back on).

Started car up. Car ran at 13.8:1 on cold start. Got leaner as car got warmer. At about half temp (on gauge) it was around 19:1.
Got to about 22:1 at full temp, was barely able to keep itself running.
Turned key off and AFR's remained at 22:1. Its as if none of the injectors on that bank were working, but while it sounded like it was struggling, it didn't sound like it was running on 4cyls.

Tested injector current on CRO. Got almost identical results to this.
http://images.picoauto.com/sat-amps.jpg
All 4 injector drivers gave identical results.
Tested resistance at the ecu end, all the same.

Unplug either ignitor when car is struggling at >20:1 and instant stall.
Unplug AFM, no change
Unplug TPS, blip back to healthy, then straight back to struggle
Plug TPS back in, blip back to healthy, then straight back to struggle
Tested Coolant temp sensor at ECU end (ecu unplugged), gave 322ohms, which is roughly 70-90degC, which would be almost spot on.

I'm hoping to replace the capacitors for the ECU on the weekend, hoping that orks.
Apart from that, I'm pretty much out of ideas.

The only thing I have tested a dozen times is the voltage at the injector while running, but surely if the current is the same, the voltage HAS to be the same (assuming resistance doesn't change, which it doesn't)

I'll recheck the AFR's on the passengers side on the weekend, make sure they are as per factory.
I'm pretty sure they are, as when you check codes after a long run, it throws 'drivers side o2 sensor' (code 28) - which I'm 99% sure is caused when the ecu senses a 'lean condition' for a prolonged period of time.

[CrUZida]

I should point out that when its only just running, if you turn it off, and then back on again, it runs normal for a few seconds, then straight back to struggle land.

I'm guessing its running on the crank map for a few seconds after starting.

[oldcorollas]

checked TPS directly?

[CrUZida]

I know the IDL contact is working fine, but it may be worth replacing it with another one.

Although, doesn't explain on side being leaner than the other

[CrUZida]

Out of curiousity, could having the exhaust cam being 1 tooth out be causing this? (remember, FE head)

[RA35GT]

Cruz,

Haven't you already ruled out the electrics as being at fault here? i.e. changing capacitors shouldn't effect it?

[RA35GT]

Another thought, not sure how long the wiring is for the injectors, but can you swap the wiring for the passenger side to the driver sides? then test. both sides.

If driver side still lean, its obviously mechanical, if passenger goes lean its electrical. From all your other tests, I'm gonna guess it stays the same and is mechanical.

(You could also check the duty cycle of the injectors in each bank, reasonably confident that same duty cycle with the same injectors at the same voltage and fuel pressure should result in same fuel output, thus still leading to mechanical?).

If the cam timing was out and the ecu thinks its rich and is leaning mixture out, it should still revert to open loop in the high load areas though? (Not to cluey on the 1uz's but)

[CrUZida]

I've pretty much ruled out everything as being a potential cause.

Its now time to guarantee its not the problem.

Also, if I can't fix it, I'm taking it to an EFI specialist (coz they love playing with modded cars...), and this way I can tell them what it definitely isn't.

[oldcorollas]

can you easily check if the cam is out? sounds like it is worth a try..

[3sgte]

What is the history on engine repairs?

Have the cams been out of the engine? Are they timed wrong with respect to each other (at the scissor gears)?

Regardless if it is easy or not, cam timing ought to be checked.

[CrUZida]

I pulled the cams out about 4 months ago and redid all the shims.
I'm 99% sure that the inlet cam is right, because I've been told that the ecu will throw a code if the timing on the cam/crank sensors isn't right.
But before I do it, is it possible to cause this (I'm thinking not)
I'm also 90% sure the problem was there before hand.

Pulling the drivers side cams out is probably one of the hardest things to do on this car. (can't get cam cover off without dropping the crossmember 1-1.5")