Ali SC3

iTrader: (10)

I am not even sure they make vvti style injectors or odb2 in larger sizes, and only in the pictures do they seem similar, I am not positive even those 2 are the same as one is plastic and one is metal but I think they are more similar than odb1 vs all the others.

Really what I think most people do is get odb1 lower runners and that takes care of the problem.

BuffNStuff

I just noticed that the vacuum line my MAP is tapped into is the line that goes to the VSV that also has another line going to the fuel rail. I assume this is a fuel pressure control vsv. Could this be the reason that I am running lean at idle? The shop I had my car at rigged this up, and I know that the MAP should have its own source of vacuum. I figure this could be my issue because it involves a fuel pressure component that might not be getting a good clean vacuum source.

I am also looking for a OBD1 lower intake manifold, but I figured I would check to see if anything else fixes my lean issue first, and then install the lower runner later for safety against a fire from leaking injectors.

Ali SC3

iTrader: (10)

as long as the map sensor is connected before it goes to the vsv then its fine.
that vsv only turns on on a hot start and generally makes it run richer. IF it is not working correctly it could affect other things, so if you want to test it simple remove the line going to the vsv and run a line direct to the FPR which is how odb1 is setup.
so line would goes from intake to FPR, and you can tee the map into that line.

what that vsv does is it is normally open to allow the FPR to see manifold pressure, but when you hot start the car (car was at full warmed up operating temp and was then shut down and then restarted in a short period of time) it will normally run lean for a minute with no vsv, so what the vsv does is it closes and the FPR can no longer see vaccuum or the load from the intake, and instead sees ambient air (from the bottom of the vsv there is a filter looking round thing), and ambient air is about 9 psi above what you idle at generally, so that basically bumps up the fuel pressure 9 psi which takes care of the lean problem. Personally I would just disable this on a turbo car because if you start boosting in the first minute of a hot start the FPR will not adjust up the fuel pressure more than ambient air to make up for the boost, and you could run lean in boost until the vsv decides to open again.
Remember the fuel pressure is dictated by the manifold pressure, hence the vac line running to the FPR. the more load it sees, the more fuel pressure, so thats why they did that for the n/a because you wouldn't need above ambient air which is the max fuel pressure an n/a would normally achieve, but when you add a turbo, that ambient air is no longer your max and it would swing lean in boost if you got in after a hot start and boosted away. I would think the GTE does not have the vsv or if it did it would open again if it saw boost, well we can hope at least but I would take it off and not risk it.

This is most likely not your issue but could be messing with the ecu so just bypass it for now. With how fast the gte ecu adjusts with a heated o2 sensor its not needed on a hot start mine will show 16 for like 30 seconds and then the o2 kicks in and its 14.8 again. you do not need that vsv there at all. leave the connector on it to avoid a CEL, but just don't run the vac lines through it, you can just use a connector to join the 2 lines together for now. I would disconnect the connector and see if a CEL even comes up though, that will let us know if the gte ecu is looking for one of those, and hey it might even control it properly where it opens up in boost again if it has a code for it it likely was handled by toyota already.

You do want the black vsv working next to it that goes to the charcoal canister, if the gas tank is not venting properly, then that can cause all sorts of wierd lean conditions that you cannot get rid of. If you open your gas tank and it sounds abnormally loud when the air is wooshing out then I would look at the evap system/canister/black vsv. If it sprays fuel at you because of the pressure then there is def a problem.
If it sounds normal a little noise then its probably ok, seeing as how stock your car was if you didn't mess with it its likely ok, just need to make sure the gte ecu uses the same pin for EVAP control. since there is no code I would think its working fine but worth a mention.

I am pretty sure the lower runners are your problem. spray some soapy water and look for bubbles or you can try the other stuff that will make the idle increase when you spray it on a leak.

Did you cap off both ends of the hose yet going from the IAC to the lower runner, its just one hose I hope you have capped it off at least by now as a test.

BuffNStuff

Yea i capped it off a few days ago. I didn't notice any changes in how the car ran unfortunately. I will tee the map somewhere else and bypass the VSV and see what happens. I tried looking for leaks earlier but did not find any. Couldn't get to all the injectors, but the ones I did spray were not leaking.

Ali SC3

iTrader: (10)

I see, yeah I can't really think of why it would still be having issues. maybe you can take a video from cold start as its warming up or when having the problem since we have progressed so far on it now.
The map sensor on the US gte ecu does not affect the fueling at all, so it shouldn't be that unless the vsv was doing something funny. as I said leave the map teed in but just bypass the vsv. that is how mine is connected and mine only runs off the map.

Ali SC3

iTrader: (10)

I updated post 1, I undid the extra 2 cam sensor grounds and it runs the exact same still, so I took out pins 5 and 6 and only have the factory wire going into 7. Just as I thought after seeing the diagram they are all connected to ground inside the ecu anyways so this is pretty pointless they only did that on the gte cause it came from 3 different places. updated a few other things but I still need to update the picture to not show the jumper for those pins but its on other computer.

BuffNStuff

Here is a video I took of the cold start up. I took this video right after bypassing the fuel pressure vsv. No change, just as you said, it wasnt the issue.

Ali SC3

iTrader: (10)

Well its got me a little stumped because it starts great and goes right into closed loop almost perfectly. then it gets a little warmer and the problem comes up. Usually adding load like putting it in gear or turning on the a/c will help cover alot of issues so I am not surprised its more stable in drive. I am guessing playing with the TPS did not stop it from doing the hunting in park? If its not the runners then it could be an ecu issue, but that is just a guess.

Maybe next time before you start the car unplug the IACV and see if it still surges. want to know if its Iacv or something else.

BuffNStuff

I unplugged the IACV before a cold start today, and right off the bat the rpms went up to 2400 - 2500rpm. I shut it off after about 5 Seconds of that because I don't wanna get complaints from the neighbors. Is the IACV supposed to be open all the way if it's unplugged?

Adjusting the tps helped with the surging when it was warm because that is when I adjusted it. I am looking to get a whole intake and throttle body from a 93 that still has the tps on it so hopefully that will clear it up since it most likely hasn't been taken off.

ashtray

iTrader: (12)

@BuffNStuff It seems fine in drive...does it actually drive around okay? is the only issue it is neutral and in park? where exactly did the ecu come from?

BuffNStuff

Yea if the transmission is in drive or reverse, the A/F ratio is good including while actually driving. Driving issues are just the 2 transmission codes that I explained in an earlier post. Also I seem to be having an issue with boost. It falls on its face and breaks up bad after 5psi. I'll worry about that when I get it idling correctly.

The ecu is out of a 1997 usdm tt auto supra. The guy who sold it to me was in Canada but since obd2 is working, it definitely is a USDM ecu. Plus I looked up the part # on it to confirm what it is.

Ali SC3

iTrader: (10)

yeah I would think if the injectors are just barely sealing its not going to hold up to boost very well.
I did see that they do sell injectors for the IS300 online in 550cc that look like they can even work with the odb2 runner with the air assist, although I would still cap that off. If you change the injectors you wont have to go through the hassle of changing the lower runner, maybe that would be simpler.

ashtray

iTrader: (12)

@ali where did you find these injectors? I have a set of RC 550cc's that I'm not thinking will not work with my OBDII lower runner.

SCereal

iTrader: (4)

everybody's favorite auction site has them. Search for IS300 550cc injectors and the first one that pops up looks like the ticket. They have the funky size/shape to them.

FWIW I ordered my injectors from the same seller and was pleased with the transaction. They were all flow matched within a couple CC and shipped out pretty quickly. Labelled and all the orings were intact. I'll be running Ford injectors on my setup so no experience with these particular ones but hopefully helps at least with a positive review of the seller.

BuffNStuff

Only thing with going that route is that we don't know for sure if they fit. But we do know I can switch out manifolds. I don't wanna risk it and end up with 2 sets of injectors I can't use. I'll just bite the bullet and swap manifolds. I found one from a 93 including throttle body and tps for $85 shipped so I am going that route