7mgte stumble HELP

[cre]

D'oh.... I didn't remember that this was a swap. Please put your truck's details in your signature so people reading know what you're dealing with.

I would definitely check the AFM's wiring, especially if the TPS wiring was the fault in your last thread. Is the fuel pump resistor and relay in place? From what I recall, on the 7M's setup bypassing the fuel pressure up VSV would cause issues with warm starts and warm, low load performance so you may want to try running the vacuum line to bypass it for diagnostic purposes.

[ccguy]

if i remember correctly i did not run the fuel pump relay or resistor.
http://www.cygnusx1.net/Supra/Librar...ection=FI&P=70
if i remember correctly i did not run them because i (at the time) only had the inline pump. and i read that it dropped down to like 6v or something like that so i just ran the cor.

i also got a bunch of info off of supracharged.com as well. i will check the volts going to the fuel pump during the stumble and see if they are 12v.

http://www.supracharged.com/tech/wiring/c1.shtml

i will go back over the wiring and let you know how i 100% wired it.

[ccguy]

the fuel pump is running and wired correctly.
i found some real wiring diagrams specifically for the 87 7mgte. so i need to check my wiring and see where i missed something.
http://www.turboninjas.com/mk3supra/
feeling good about it now.
thx for the encouragement. i will let you all know what i find. thx

[cre]

FYI, the absence of the resistor and relay for the fuel pump is a positive in troubleshooting this. The reduction in power to the pump that it provides at low loads isn't a negative and helps low load operation. If its absence were the problem though you'd know by checking with a wideband for an overly rich mixture. It will not hurt the fuel pump to leave it in place and no, it doesn't reduce the power to the pump to that significant of a degree... most of the negative commentary you see concerning that device comes from ignorance spread through old wives' tales or is misinterpretation from feedback from people who've had to tune after market engine management components around it... Sometimes it's just easier to delete.

[ccguy]

i have a feeling it is in the HAC.
when i have it connected, the tps at the ecu it is 2.8 k ohms.
when it is unplugged it is 4.8k ohms.
with it plugged in it runs worse and with it unplugged it runs like in the video. so?????????

there is 4.8 volts from the ecu going to the hac with the ign key on. as well to the tps and afm.
does anyone else know what their vta k ohms is with the hac connected?

[ccguy]

my hac ohm measurements is
vc-p = .786 k ohm
vc-e2 = 2.89 k ohm
p-e2 = 3.67 k ohm

so the vc-p is not in spec. does anyone have one they can test and see what they get? i am using a 114 fluke digital meter

page 121
http://www.turboninjas.com/mk3supra/...-EFISystem.pdf

[cre]

Try using a voltage divider/resistor network to bypass the HAC and see how the engine operates with a static signal. You'll want between 3 and 3.5v for sealevel.

See here for some more detailed instruction.

[ccguy]

so my hac is reading 3.04 volts and i am at 6500 ft elevation.
would that sound about right for what it should be?
i am going to do another video and show you guys what i mean by when it acts worse with the hac connected.

[ccguy]

there is NO difference if i unplug the O2 sensor. nothing.....?
if i unplug the tps or the afm it wont run for crap.

here is a video driving. notice at the end where it accels when i barely have the throttle cracked.....could that be my iacv sucking in air past the tb?
when i say it "bucks" it feels like as if you would pop the clutch or wot then let off. feels like it is going to break a u joint or motor mount

http://www.youtube.com/watch?v=eDLr4...ature=youtu.be

also i was thinking about the hac. as the altitude gets higher it tells the ecu there is less o2 so it reduces the amount of fuel sprayed (right?) so in theory if it is a lean fuel issue pluggin in the hac would farther confirm that due to it cutting the amount to be sprayed.
hopefully the fuel pressure gauge will get here within the next 2 days.
with the pressure gauge could i put it on before the fuel rail? basically just before the dampener or should i try it on the rail like off of the cold start inj?
i will probably try both just to see how it fluctuates

[cre]

I'm stuck typing one-handed for a while so this will be brief.

If you supply the HAC input with a static signal for sea level and the car runs better the it's likely running a bit lean normally. HOWEVER, leaning out or enrichineng can also compensate for other issues such as bad timing (mech and ign). Just unplugging the HAC may put the ECU in a failsafe mode (just as far as the sensor in question's input is concerned) causing the ECU to add a little more fuel on top of the trim for sealevel. Use a resistor network to provide the ECU a true sealevel signal, it's only a matter of sticking two resistors in the harness connector.

O2 sensor won't make any difference except for after warm starts with it disconnected (you'll run rich) and during closed loop operation at normal operating temp.

Before the damper is the fuel rail. If you're referring to the return then no, that's not a pressurized hose. Yes, use the CSI's port on the rail.

Have you tried another AFM?