Horribly degraded performance

Lol! You really need to grow up.

 

Do you always make a point to argue with people that are trying to help assist members? Last I checked you were the one attacking and you want me to back down. This thread is from a person requesting guidance in solving a problem. We are all here taking our time to help the person without compensation assist in providing a solution. We are all here to help one another. You appear to want to attack for some reason. Lets stay on topic and stop the nonsense.

 

So interesting thing happened yesterday. I was parked on a slight incline of a driveway. I get in the truck and turn the key and the engine kicks off on the first turn. It usually takes like 4 or 5 turns to get going and FINALLY I get a check engine light. Bank 2 system too lean. I'm not sure how that could have made the engine kick off on the first turn but it only happened that one time. Another interesting thing is that the truck seems to be running a little bit better. I say running better meaning it seems to be more responsive than how it was. If anyone has anyone has any input on that, fire away.

 

https://autoservicecosts.com/obd2-codes/p0174/

Error code P0174 is described as System Too Lean (Bank 2). This means there is incorrect ratio of air and fuel on the car’s engine system

Going further:

The oxygen sensor then relays the information to the computer and uses it to determine how much fuel is needed. The computer will then set the fuel flow (and even other related operating characteristics of the system) to maintain the right ratio of air and fuel combination. This loop goes on and on as the engine runs. The error code P0174 appears when the computer can’t maintain the right ratio of air and fuel

You may want to check those items. Good luck and ignore the noise.

 

Not arguing and not attacking, kid. Making sure the OP doesn't follow your bad advice in your first post. Moving on - the OP has been sufficiently warned.

 

Thanks for the compliment.

 

The pump and filter could cause a lean condition.
Guys running the TRD Supercharger have had issues with the filter.
Yes, the filter can restrict flow in as little a 30k miles. Enough so, it can cause a lean condition.
Sine the truck in this case has 330k miles, I don’t think it would be unreasonable to suspect fuel pump and filter issues could be a cause. Especially since we know the pressure was low when tested.



You can read about it below.
https://www.tacomaworld.com/threads/fuel-pump-question.536535/

 

Question about the fuel pump upgrade. Do you use the same housing as the previous fuel pump?

 

Pretty much. The filter housing is removed with the old pump. The new pump is stainless zip tied to the plastic housing.

 

Once again I am eternally grateful for yalls help and support. I will order the part sometime in the middle of the week and I will let yall know how everything goes.

 

This mean that you perused through the It's website and ordered a fuel pump kit?

 

I've been running two nylon zip ties to hold the pump in place, I ran them because I didn't have any stainless zip ties and because nylon is impervious to petroleum. No problems for the last 5 years.

 

well Yotacoma08? what was the outcome???

 

DAMMIT…. Lol this guy has the exact same issues I had, but a LOT more support…

did my vacuum test no issues,
replaced MAF WITH OEM
replaced throttle body with new OEM
REPLACED VVT SOLENOID + Screens with OEM
Plugs are new URD
A/F sensors are new DENSO
O2 sensors are new DENSO
Replaced Fuel pump with walbro 255
Checked that damn connector in the driver side kicker for high resistance issues, looked clean.
Ordering a new fuel pump resistor since mine looks like it’s 40 years old.
Replaced fuel pump relay
Need to run a fuel pressure test when the thing is running, but even if the pressure is low, what else is there to do about it? The other two relays quoted earlier that control pump speed??

FYI, I know I’m getting lean moments through the UCON charts.

cheers

 

Not complaining either, cause I technically got the support as well, just a dammit because he never wrote the final part of the story!!

 

If the pressure is low, chances are the pump is bad, or the in tank line is leaking.

Do you have a scan gauge, ultragauge, or scan tool to monitor fuel trims? Might work, even though you have a UCON. If they are too far out, that would be a relative way of determining a fuel pressure problem.

Do you have any check engine lights?

 

The Fuel Pump Relay controls the speed of the fuel pump.

The COPN Relay is what actually energizes (turns it on and off) the fuel pump.

 

Hey guys,

thanks for jumping in.

-No CEL.
-No Scan gauge, but down to get one and LEARN me some engication!
-Put the pump in myself with the fuel line from URD, and noted to ensure the in tank lines were as secure as humanly possible with hose lamps.
-Funny thing, I have a spare walbro from URD as they didn’t take that out of the S/C kit and my dumbass ordered one a few months prior to jumping on the boost train so I got 2. Not a terrible thing . Will replace if I run out of other options and I can prove it’s a pressure problem.

Also an FYI to new thread readers, truck ran better when replacing the TB, amazing how much springier it was compared to the old, even after cleaning.
Truck ran better after replacing the A/F sensors and O2 sensors, difference was noticeable.
MAF sensor replacement was meh..

Might have follow up questions after doing some research. As always, thanks guys!

 

Ok, so looked into scan gauges and had a “DOH!” Moment when I realized that they’re basically OBDII Readers. Of which I have the blue driver, didn’t know anything about fuel trims (aside from hearing the term here and there) until now, and have uploaded a log showing fuel trim/timing activity.

Definite action going on with fuel trims.. not entirely sure what it means, seems all over the place and am doing some research on it…

 

Ok, continue getting up to -100 negative fuel trims for both banks.. tried replacing the vacuum controlled fuel return valve (located on the end of the fuel rail), but that didn’t change a damn thing.

noticed temperature fluctuations reported in the engine coolant temp OBDII readout that can’t be right.. dips going from 90C to 3C within .2s

Perhaps the ucon uses temperature modulation to force the Ecu to perform a certain way..

don’t have any other ideas for what could be going on, when I scanned for all system codes, there are soo damn many that pop up, but they all seem completely not meant for my truck.