petershen

So I bit the bullet and bought the whole fuel pump assembly from Megazip... I've got 3 kids now and have limited DIY time so I'll pull the rear seat and try to swap out the damn thing tomorrow.

It was hideously expensive.. the local Toyota stockists don't keep many parts for the GS450h
https://www.megazip.net/zapchasti-dl...?q=77020-30221

petershen

Thanks to @Lwerewolf and @hybrid450
The fuel pump solved the idle wobble... I can't believe the solution to this after doing all that troubleshooting... I'll post more pics later in my build thread. The fuel filter and sock were so caked up, I don't know how the car actually ran like this... with the new pump the car drives much smoother, seems stronger when overtaking.

I thought I ordered the wrong part but the GS450h's pump is really held down by a compression steel ring with 8 M6 bolts.

hybrid450

Nice, happy to hear that it solved the issue! Also nice that you could get yourself a whole new thingy, I wish I could do that too back then, maybe it'd be even better, but I think it runs smooth and the performance is great, so until this pump gets somehow clogged, I am not changing to a new one. I am curious what were your long fuel trims before and after replacement, but I guess you didn't check? Currently I am having +7% max when full throttle, ~+3/5% when driving with half throttle, and ~ -5% when idling. Just to remind - before fuel pump replacement, trims went as high as 15/17% when it was knocking, so it's a lot better, I just wonder if it would be closer to 0 with a whole new pump assembly.

petershen

Before replacement I was +8 @ WOT thereabouts I think... I do remember checking some months ago but haven't been as diligent as you both in datalogging I had no codes, just a stumbling idle from time to time which really annoyed me.

Maybe it's my driving style as I live on an island so I hardly have any freeway driving, it's mostly around the city with occasional sprints.

This is such an amazing car, I plan to keep it for another 10 years if possible. I'm glad I found a few of us who actually know this car well.

Lwerewolf

I just replaced my filters, disassembling this thing is a bit annoying.

Note that I have NOT replaced the pump itself.

Trims didn't really change, "weird" idle still happens whenever it likes. My trims don't go above 7-ish long term, though, so... they weren't irregular to begin with.

I still haven't done a smoke machine intake/exhaust leak test, which should've been the first thing.

Xenith

Interstig i was thinkling of changing the fuel filter as well hoping to 0 out my fuel trims .( how much was the filter they are like $90 here in aus)

petershen

After a few good days of driving, my cold start RPM is higher by about 150rpm, hovering around 1050-1150, previously used to be just under 1000.

I'm getting a slight wobble again but this time it feels more engine/transmission mounting related... which is fine with me. At some point I'll need to replace the transmission mount, it looks massive!

petershen

Long term fuel trims are finally coming down... I didn't reset the ECU when I changed the pump (but I don't think long term fuel trims are cleared by that?)
First few days after the pump went in the fuel consumption was horrible.

Now I need to replace the 90Ah battery on my wife's old BMW E70 X5... that thing eats batteries, though I must say it drives very well for such a truck.