[FIXED]1jzgte issues

Hello all. I'm working on a Toyota MX83 with a swapped 1jzgte vvti engine. I got it as a cranking no start, got spark, injector pulse and adding carb spary made made little difference. I decided to inspect spark plugs and confirm good compression and found oil and carbon fouled plugs. The fouled plugs and rocker cover gasket were replaced, car started but had idle issues but this was even before it reached the point of a no start because the idle valve was blocked off.

I returned the next morning because the owner's helpful son-in-law removed the alt and drive belt before I got there. Anyhow, got back there and confidently cranked and the idle was in the toilet, start, run, stall with little to no response to throttle input unless carb spray is added. I decided to ramp the fuel pump because Toyota fitted this car with some lovely crimped fuel lines and fittings, no room for my ghetto fuel gauge.



With the settings on my clamp it would be around 5 amps. Would you say this is a slow turning pump? This pump has been in this car from as long as the owner could remember and before it was a no start the car had running issues, stalling after running hard or when hot sometimes and would need to rest to start again.
Any advice would be appreciated.

Would you say this is a slow turning pump?

To calculate RPM's, pick an identifiable hump. Count how many humps until the identifiable hump repeats. This is one revolution. (usually 8 humps, I think). Set your cursors to see how many milliseconds in 1 revolution.

1000ms = 1 second
60000ms =1 minute

Divide 60000 by the milliseconds indicated by your cursors to determine pump RPM's.

What is the amplitude of the wave? All in all, that wave doesn't look terrible, to me. But, I'm sure some others will be chiming in, soon.

Would you be able to post a higher quality version of that photo?

Trying to pick out some points on the waveform... If that's a 1ms time base, then it's a 10ms screen. Eight humps takes about 9/10's of that screen, so it's about 9ms/revolution. This works out to a pump speed of about 6600 RPM, which is pretty normal for a fuel injection system.

Five amps isn't amazing, but not horrible, either. Does this engine use a MAF? Wonder if it's skewed enough to cause this poor fueling issue. Most Toyota engines I've seen rely heavily on the MAF, and don't always have good back-up strategies. :lol:

Update:

*Fuel pressure is 35 psi @ idle and 42 psi on snap throttle.

*I observed a liquid was present in the PCM plugs. I used MAF cleaner (also used for cleaning MAF) to clean it off but made no difference.

*With KOEO the PCM actuates the solenoids of the transmission and the vvti continously. I was thinking maybe it was seeing an input when it shouldn't. Checked CKP, CMP with scope at the time but they were not sending and MAF (unplugged it) but it continued doing it. Loooked for information for if this is normal but I never saw a jz do that.

*The pin designated for CEL (W) #3 on 16 pin jack will not ground the circuit (checked with scope). Even jumped TE1 to E1 to cause the light to flash but got no response. Power grounds checked good.

*Engine starts, run, stall but sometimes it can be kept alive with throttle. If it stalls it's a PITA to start

*Recommended a replacement PCM and I'll rewire. Sorry for being parts changer but that liquid residue concerned me. Thank you for input as usual everyone.

First I would hook a scan tool up and check fuel trims, codes, other data. It sounds lean just from what you said about the carb spray. But it could also be ignition timing, mechanical timing, restricted injectors, bad gas, throttle cable adjustment, etc. Gather some more data.

Also, judging by the waveform that pump might be pulse width modulated, and if its not at 100% duty cycle its impossible to pick out unique humps for an RPM calculation.

Here are the engine control wiring diagrams for a 1992 cressida. Granted I'm not sure how far in depth the engine swap was, but the fuel pump's speed is controlled through a five pin relay with a resistor on one side of it. I only quickly glanced at some of the wiring, there is some interesting cold start controls, and also the air meter seems to be tied to the fuel pump through a "circuit opening relay"

lol this is some strange 90's wiring man that i'm not to familiar with. plus how much of the harness had to be swapped with the engine?

read the fuel pump portion on page 59

Issue was solved with PCM replacement. Owner can carry his grandchildren to school under boost once more.