just got my lexus afm and 550s in and it's running rich. I set the fuel pressure to 28 with the vac hose off just wondering if I'm doing it wrong or have it to low. it's gonna be getting a tune this week. any suggestions on where I should set the screw on the afm and the fpr?
Lexus afm and 550s
- Thread starter BryanDyer
- Start date
Just being curious, how do you know it's rich unless you have a wideband?
The point to lex afm and 550cc injectors is that they don't need tuning. Both are 25% bigger than their counter parts.
Keep your fuel pressure set to stock, 33-40 psi with no vacuum. As for your afm screw location, hook up a multimeter to your vf/e1 ports in the diag box under the hood, your goal is to get VF to read 2.5 volts. You will have to play with both, the afm set screw and the fuel pressure.
Since you're able to adjust the fuel pressure, I'm going to assume you've also done a walbro 255 fuel pump swap and bypassed the j-tube under the intake manifold?
What other mods do you have done to the car?
The point to lex afm and 550cc injectors is that they don't need tuning. Both are 25% bigger than their counter parts.
Keep your fuel pressure set to stock, 33-40 psi with no vacuum. As for your afm screw location, hook up a multimeter to your vf/e1 ports in the diag box under the hood, your goal is to get VF to read 2.5 volts. You will have to play with both, the afm set screw and the fuel pressure.
Since you're able to adjust the fuel pressure, I'm going to assume you've also done a walbro 255 fuel pump swap and bypassed the j-tube under the intake manifold?
What other mods do you have done to the car?
well I'm saying its running rich based on the exhaust
i messed with the fpr a little and have it at about 38-40 with the vacumm
i was just assuming it was running rich becuase of the idle and exhaust and it has sort a sputter sound like a skip I guess while at idle
i messed with the fpr a little and have it at about 38-40 with the vacumm
i was just assuming it was running rich becuase of the idle and exhaust and it has sort a sputter sound like a skip I guess while at idle
Wideband is a pretty cheap thing to run. I almost skipped it on mine, but very glad I have it now.
I am planning on going standalone later on, but I have the same mods as you are listing and did a thread that has a lot of discussion regarding this that you may find helpful...
http://www.supramania.com/forums/showthread.php?171661-Planning-2014-Standalone-Upgrade-Question...
I am planning on going standalone later on, but I have the same mods as you are listing and did a thread that has a lot of discussion regarding this that you may find helpful...
http://www.supramania.com/forums/showthread.php?171661-Planning-2014-Standalone-Upgrade-Question...
If you just changed out the AFM and injectors, reset the ECU, then let it learn in closed loop mode. Until it does so, your AFR is going to be all over the place, and rich by default.
Once the ECU has spent an hour or so in closed loop mode, it will run much better. My '90 runs like crap for the first while after an ECU reset, but does quite nicely once it's had a chance to learn.
Once the ECU has spent an hour or so in closed loop mode, it will run much better. My '90 runs like crap for the first while after an ECU reset, but does quite nicely once it's had a chance to learn.
IndigoMKII;1917404 said:
This would be at idle correct?
OP, I swore up and down that my car was running rich at idle. Every time I would try to take off it would stumble and not accelerate. I have a used AFPR and gauge. That gauge isn't accurate at all, and it's losing its fluid. I installed a wideband and found that I was running really lean, and it wouldn't accelerate like that. I would have known this if I would have at least hooked up my multimeter and read it. Fuel pressure gauge was already showing 34psi, but the gauge was faulty. I cranked up the fuel pressure, and idle smoothened out, car started accelerating normal.
I still need to hook up the multimeter and see if I'm at 2.5v. It's so easy to do, but I don't get around to even looking at my Supra but maybe once a week. Then I forget all about doing it. It runs good though.
Like mentioned earlier, drive it around for a while and let the ECU figure out closed looped operation. Then hook up and multimeter, check and adjust it accordingly.
1. Pull EFI fuse.
2. Wait 30 seconds.
3. Install EFI fuse.
4. Start and drive (nicely.) Let the car warm up to operating temperature, and drive around for an hour or so. The engine should settle down and idle better. As it learns throttle response will get better, too.
2. Wait 30 seconds.
3. Install EFI fuse.
4. Start and drive (nicely.) Let the car warm up to operating temperature, and drive around for an hour or so. The engine should settle down and idle better. As it learns throttle response will get better, too.
Nick M;1917533 said:
He doesn't know if it's rich nor lean, that is speculation because he doesn't have a wideband.
Suprapowaz, you would want vf/e1 at or near 2.5 volts all the time throughout the rev until it switches to open loop, then you can adjust the afr with a safc or similar. The vf being 2.5 means the ecu isn't having to make as many corrections to keep the afr within the range it wants to be in.
Depends how far off from the ECU's fuel model you are. On my car, I really don't feel any difference between a fresh reset and after some driving time because I am very close to what it is expecting. This ECU doesn't have much retained memory (only 16 bytes) so there isn't much to learn, and half of those bytes are used for storing codes.
And that's the trick.
I get no noticeable correction in my '89, but the '90 doesn't like to idle until after the ECU corrects itself. The '89 has the Lexus AFM and 550cc injectors, the '90 is stock AFM and injectors. Go figure.
I get no noticeable correction in my '89, but the '90 doesn't like to idle until after the ECU corrects itself. The '89 has the Lexus AFM and 550cc injectors, the '90 is stock AFM and injectors. Go figure.
3p141592654;1917689 said:
^ This. The whole "resetting the ECU to fix problems" thing needs to die. If doing so has any effect there's something else wrong with the engine.