No Throttle Response Randomly

That's much better than dropping 3-400 bucks on random parts!

I'll do this Monday after noon and go on a road trip next weekend an let everyone know!

 

So im going to pick at your knowledgable brain... i have long tube headers and 02 simulators to keep the CEL light off, i'm thinking the 02 sensors may be fouled, but i'm not getting a CEL due to the simulator. So in theory when i put the factory manifolds back on, and if i have a CEL, i'll actually be able to diagnose my issue?

 

Pat did I read somewhere that you said you didn't have the MAF sensor spacers that come with the afe kit installed?

 

The little white spacers, yeah don't have them

 

I've had my DTLT's and O2 sim on for 50k, no problems at all. I had the exact same idle/stalling/bogging down problem you have intermittently. I had installed the problematic 2nd Gen TRD intake when the truck was brand new. Not until I swapped it out for the stage 2 si did it go away, never happened again. I might be way off but I think it's something to do with inefficient air tube diameter/shape and MAF sensor placement within the air tube causing inconsistent airflow/airtemp readings, thus affecting other split second calculations either directly or indirectly, such as: throttle load/throttle body position, AF/O2 sensor readings, variations in valve timing and transmission load/gear/psi readings. All of which contribute to determine the correct Air/Fuel ratio to deliver....... Sooo in a nutshell, those 5/16inch MAF sensor spacers that are supposed to be there aren't.










....... But I could be waaaaayyyyy off. I could give another theory if you want? Has it done it since you removed your CB radio? Lol

 

The flash makes that happen. The recall included changing the floor mats, chopping the pedal and the flash.

 

Whats the other theory?

 

Actually that was all, sorry man. But seriously, Cbass and Torspd have probably hit it pretty close. The engine isn't dying so fuel and air are still getting there, so that should rule out the fuel pump theory. Now your driving down the freeway and while your driving the ecu is constantly running tests on the engine and emissions systems. The important part about this is for certain tests to run, your driving must meet certain criteria, example: maintain 35mph for 8 minutes then drop to 25mph and immediately accelerate to 40mph. Once the ecu detects that a particular test criteria has been met it runs the test. If the minimum or maximum set values of a test are exceeded, depending on which system is providing the results (in your case I believe the induction system is the cause) the ecu will default to safe mode and a generic air/Fuel ratio and throttle body blade position will be held until test values are once again within safe operating parameters. Just another one of my theories. But I think I might be on to something. So culprits could be; "intermittent faulty brake switch" which would go against my entire post, "intermittent faulty throttle position sensor and/or throttle body communication", "faulty O2/AFR sensors" which would normally set a CEL but the O2 simulator might keep those values within optimum range which would show a steady 14.7 as the sensor is not feeding it baseline readings. And finally what I think and hope it is "incorrect MAF sensor Target placement within the 3-4in diameter intake tube due to no spacers and I'm guessing the supplied MAF foam seal that comes with that particular CAI might be missing too......... Oh did I mention vacuum lines?

 

One of my 02 sensors was barely threaded on the long tube headers.... possibly the problem!

I do have the gasket for the intake just not those washers

 

Dude, I really think your ECU is borked from that jacked up URD MAF calibrator. My truck has never had that issue and running the intake/dtlt/exhaust/o2 sim...

Also that O2 sim is a bypass, it doesn't care what the actual reading is so it's not going to cause that issue.

 

The urd maf didnt end up being the cause, it did it before,during and after i removed it

The 02 sim wont cause the issue, but it could cover the cause by not allowing me to see if an 02 sensor is fouled

 

If you are using an O2 Simulator the O2 sensor being fouled or not doesn't matter as the ECU isn't using the readings from the O2 Sensor.

 

Ahhhhh i gotcha

 

Technically it doesn't bypass the O2 data, the sim needs the fluctuating readings from the sensor as a baseline. It then fluctuates the signal identically at a calculated lower percentage. The sim is capable of hiding a somewhat degraded O2 sensor. But if the sensor takes a complete dump you will get a CEL regardless of the sim.

 

I didn't read all 8 pages, but it sounds like a clogged fuel filter to me. I would strongly suggest replacing it. Mine ran fine around town, but when it would only do 105 I knew something wasn't right. Then it would act like it ran out of gas on a long pull, but if you let off the throttle a little it would go faster. I don't think it is o2 sensor related at all, my upstream 02's were trash and it still ran, it was just really rich. The downstream o2s are there to check the cats only, and your URD gidyyup deletes those anyway....FUEL PUMP/FILTER IMO. Next guess is loose wire somewhere.

 

Wait, I remember you didn't upgrade the fuel pump, correct? I agree with him ^^^^ So excuse my previous comments about the sensor being the problem still.

I am about to do a fuel pump upgrade on a friend's truck because he has lost a lot of power up top, has a bit of a long start, and bogs a bit too. He has over 100k. Still should have been changed about 60k miles prior.

How many miles did you have again?

 

74k miles

 

I say change it.

Depending on the brand you purchase from, if you always drive until "E", if you fill up when the pump is pumping slowly, and fill up when the gas truck is filling the station, your filter can clog more quickly, relative to one that doesn't see th afore mentioned.

 

Hmm i used to have a terrible habit of driving it down to E

 

All of the above mentioned will help to suck up the "sediments" from the gas station and or your gas tank, and puts it into your fuel system/filter.

The potential to damage your fuel pump is also there, due to the fact that the fuel isn't there lubricate and cool it.