16 valve TPS Question

[fixkick]

your mod valve cap , number end in 60b00?
60b00 means for Suzuki G16 engines and not the common toyota that use same looking mod valve.

[fixkick]

covering more bases here.

[fixkick]

we will find it, !!!!

[Oscar]

The live test on the EGR is good(I did have to lift a wheel though). It is still running rough at idle and low throttle input. It seems to run fine above 2500-3000 RPM, especially when under acceleration. But if I attempt to accelerate from lower RPM(2,500 RPM and lower) it stumbles and then cleans up after 3,000 RPM, then runs strong. I unplugged the O2 sensor and it didn’t change. Also, I have to push the gas pedal to get it to start in the morning, which I know is a sign of a problem on an injected car.

[fixkick]

ok, High NOX.
engine misfire hot at idle? not good.
the pushing gas pedal in A.M start ups means its staving for air.
the IAC is not open. is my guess. for cold starts. In fact the ECu assumes it is open and injects cranked based on the modeling of IAC open.
or its over injecting (ECT reads wrong (too high ohms) and overfuels and you need even more air to start engine.

so is fuel pressure at spec.? at ide and at WOT , (gunned pressure increases about 6 PSI from idle.)
Make sure the MAF is clean (from 8' afar clean it with cleaner spray)
injectors not leaking,

oddly....
nox happens the most the better the combustion, nox is by product of too much heat (and max power) in the combustion chamber, all normal and is why they inject EGR gasses to cool it down a bit the the remainder is via the 3 way CAT removing the NOX last.
but if car misfires, nox is less. (so must be only some conditions NOX happens, speeds and load,)
so there are 2 problem so solve.
it seems

I can assume tuned up, spark ,wires ,cap rotor and fuel &air filter, less that say 30k ago.
Id check fuel pressure first if not already done.
The FPR on this car is too old now if original.

[Oscar]

Yeah, it will stumble coming off idle, when it’s just idling with no throttle input it doesn’t misfire. It idles up to 1200 rpm when cold and then comes down to 800 when warm...all good. Could be that it’s over injecting like you mentioned...ECT ohms? I’ll check
Might be why it only does it until I get the butterfly open and start adding lots of air. Fuel pressure is spec, maf clean, fpr testing perfect. Brand new tune up with rebuild, less than 1 K miles. And the numbers on the egr mod valve are 60b00(in response to your previous post...took me a minute to see we moved on to page 2, lol)
Thanks for all the help!

[fixkick]

the ect must be like 300 ohms hot, 180f, is that,
pull connector hot read sensor with any ohm/dmm meter made

the TPS must work , this signals the ECU that you tipped in the throttle fast and prevents TIp in bog.
the the MAF wakes up (air flow is slow and delayed) and the ECU goes to enrich mode at tip in via TPS early warnings.
also if the idle switch opens late the ecu does not see the tip-in until too late and bogs (hesitates)

this stumble is this hot or cold engine or both?

[Oscar]

It does it hot and cold. ECT checks good. I’ll recalibrate the TPS just to be sure. Would that explain the cold start issue where I have to pump the accelerator pedal? Thanks again for your help!

[fixkick]

cold start and hot are 2 different things

the ECT is next.
it must read correctly
the ECT sets the fueling rate, cold. it must read correctly for cold then 300 ohms hot.
the yellow back ground is spec. for ECT (suzuki)
the IAC sets air flow, cold cranked, and the at cold idle.
the ECT sets the fuel rates cold adding fuel to the known rates of air above. cold.
when the ECT report coolant is over 150f, the ECU switches to hot running mode. and the IAC is 100% closed now,. hot.

http://www.fixkick.com/ECU/temp-sensors.html

[Oscar]

So, long time since last post...during all the tests I decided to do a compression test even though the motor had less than 1K miles. Two cylinders at 130...not good! Pulled the motor and sent it back to the shop that built it. He said it looked fuel washed and he re-honed the cylinders, replaced the rings and that’s all he found. Finally got it back and in the car. Car is still acting the same- have to push gas pedal to start it(in the morning, cold only) and it stumbles off idle then seems to run fine above say 2500 rpm, accelerating and cruising. I’ve got to figure this out before I ruin the motor again. Any help would be greatly appreciated. I’m ready to load it up and send it to anyone that can fix it! And in response to above...ECT is reading correct for cold and hot