beaten by a 1uz

[taka21]

i think ive tried everything folks and to no avail
my summer project is still kicking my butt
i have replaced cats, ecu's, maf's and vacum hoses
and i still have the same issue of the damn thing will not rev past 4k and is kicking black smoke from running extremely rich, i just have a few final questions before i totally give up , as this project has me to the point where i am doubting myself and what little mechanical skill i thought i had gained.
1 can the idle air control valve be completely removed without harming functionality of the motor?
2 if the fuel return line is too large would that cause a rich condition in the engine
3 what would cause the maf and iacv to not communicate with the ecu?
im officially stumped with this project daily driver please anyone, i really need a direction to go in
thanks

 

[cribbj]

I run my Supra at the moment without an IACV, but I have a standalone EMS. No idea what effect it would have on a stock EMS not to have the IACV there.

Have you disabled the cold start injector? If you're constantly rich, I'd give that a try. Is the motor throwing any codes?

 

[taka21]

i dont think my 1uz has a cold start injector my motor is from a 97. im getting the maf wiring code now and thats a bout it but i cant find a breach in the wiring

 

[cribbj]

Right, no cold start injector for a '97.

An oversized return line won't make the engine run rich - but the inverse is true - an undersized or restricted return would cause your fuel pressure to go up, and it would run rich. Have you hooked up a gauge and monitored your fuel pressure?

Have you disabled any emissions controls, such as your charcoal canister or the vapor pressure VSV? If you've dumped the canister and plugged the lines, the fuel vaporising in the tank will put it under pressure, which will have the same effect as blockage or restriction in the return line.

Have you inspected or tested the injectors? Sticking injectors are fairly common and will cause the engine to run rich. You can check to see if the ECU is firing them OK by purchasing a "noid" light and plugging it into each injector connector and confirming that it pulses. If you're not getting pulses, only a steady glow, then you probably have a short to ground on that injector lead. All injectors have +12 continuous on one side, once the ignition is on, and the ECU switches the other side to earth to fire the injector.

A faulty coolant sensor will cause the EMS to think that the engine is not warmed up, and it will run rich.

A bad lambda sensor could make the engine run rich, that it should also be caught by the 2nd lambda sensor, and it should throw a code.

A fouled MAF sensor should result in a lean, not a rich condition

 

[spf_lexus]

fuel return ID wont affect richness but capping it off would (or a severely restricted retuen line). Can you verify that you have an 8 gauge ground from the rear of each head to the chassis, an 8 gauge ground for each motor mount to the frame rails, 1 ground per side of the bellhousing and a solid ground for the main harness? Start with the grounding b4 throwing any more at it.

 

[spf_lexus]

Actually a 12 gauge will work fine too, I tend to overside my grounds just from habit.

 

[taka21]

i did ditch the charcoal canister a while back and the line for that is blocked off, also im not running the secondary o2 sensors. (maybe thats why im not throwing the o2 code.)
and what could cause me to throw a code for the maf wiring im not sure how that works

 

[spf_lexus]

Like Cribbj said, capping off the vapor purge line will cause a high fuel pressure issue and thus the rich black smoke. As for the oxygen sensors, I have deleted all my cats and my engine runs fine w/ the exception for a dash light... but I also leave my secondaries plugged in but zip tied to my floor. Maybe having them unplugged is messing w/ ecu? About your MAF codes, did you manually wire this up?

 

[taka21]

which vsv is the vapor vsv i have them still but i have two on the intake manifold.
i dont have a fuel pressure guage but i did test the injectors they all pulse properly.

if the coolant temp sensor is faulty will the guage still rise up to temp on the dash cluster?
ill jump on those grounds first thing in the morning as im fairly sure ido not have that many connected.
also without putting the charcoal canister back in is there any way to keep pressure from building up in the return line?

 

[spf_lexus]

I had an issue where my 1uz would not start until a random 12 gauge line from the firewall to the head was attached, then it fired up 1st try. This was with 4 grounds already. I think the 1uz is a pit picky with grounding.

 

[spf_lexus]

is this a motor swap/conversion?

 

[taka21]

my secondaries are phisically in the exaust system but the arent connected to anything they are ziptied to the framerails lol
my first two cats are deleted as well the third cat is still there though.
yes i wired the swap with the help of a friend (electrical engineer) the motor and ecu and wiring harness all came out of the same car at the same time so its all stock wiring on that end

 

[taka21]

yes its a swap the motor is in my 87 supra

 

[cribbj]

i dont have a fuel pressure guage but i did test the injectors they all pulse properly.

I think we went through all this during the summer didn't we? Fuel pressure is one of the fundamental things you should look at. If you don't have a fuel pressure gauge, break down and get one.

Are you sure the injectors are pulsing - did you listen to each one with a stethoscope, and did they all sound alike? Good solid clicks when firing?

if the coolant temp sensor is faulty will the guage still rise up to temp on the dash cluster?

No, the coolant sensor for the dash gauge is separate from the coolant sensor for the ECU

also without putting the charcoal canister back in is there any way to keep pressure from building up in the return line?

You can run the vent line to the air intake. I would tie it in after the filter, but before the MAF.

 

[taka21]

I think we went through all this during the summer didn't we? Fuel pressure is one of the fundamental things you should look at. If you don't have a fuel pressure gauge, break down and get one.[\QUOTE]

yes we did and im still fighting with it, thanks again for all your help and input it truly is appreciated, the fuel pressure gauge is next up on my list of tools to pick up

Are you sure the injectors are pulsing - did you listen to each one with a stethoscope, and did they all sound alike? Good solid clicks when firing?[\QUOTE]

yes i picked up a stethoscope and i listened to each injector and they are all giving solid clicks when firing

No, the coolant sensor for the dash gauge is separate from the coolant sensor for the ECU[\QUOTE]

that must be the sensor right next to it then
i honestly didnt know that. THANK YOU

You can run the vent line to the air intake. I would tie it in after the filter, but before the MAF.

I didnt think of that ill do it first thing in the morning and report back

 

[taka21]

wow those quote tags didnt copy over the way i thought they would

 

[taka21]

heres a vid of what its doing now
<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/WjRpHaA64sY?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/WjRpHaA64sY?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>

 

[taka21]

fail heres a link to the vid
http://www.youtube.com/watch?v=WjRpHaA64sY

 

[gloverman]

What supply voltage do you have to the MAF? What supply voltage do you have to TPS? and the fuel pump?. Do any of these voltages change when you open the throttle? Cheers

 

[gloverman]

Whats the primary resistance of the blaster coil?