Throttle lag/ resistance 2001 tahoe

[rockola1971]

Eric is the man! hahaha

But the lack of a CEL especially not a blinking CEL (which would tell me there is active spark knock happening) which typically is traced to bad wires, plugs or coils leads me to believe this is just not an ignition (worn parts) problem. A fuel pump or a plugged up fuel filter does not have a specific code within the PCM (since there isnt a fuel pressure monitoring sensor). I would change the fuel filter first since the symptoms fit that being plugged up. Then I would check fuel pressure reading at idle and well off idle and see if it meets spec. If all checks good there then I would look at mechanical binding. Bad wheel bearings, bearings in differentials, transfer case bearings, Ujoints and even transmission issue. These of course have to be isolated from one another and checked and there are ways. For instance to rule out wheel bearings, lift each wheel off the ground individually and see if they spin freely with no bind. If you find one that doesnt move freely then you just have to isolate whether its in the differential or wheel bearing itself.

 

[OR VietVet]

Eric is the man! hahaha

But the lack of a CEL especially not a blinking CEL (which would tell me there is active spark knock happening) which typically is traced to bad wires, plugs or coils leads me to believe this is just not an ignition (worn parts) problem. A fuel pump or a plugged up fuel filter does not have a specific code within the PCM (since there isnt a fuel pressure monitoring sensor). I would change the fuel filter first since the symptoms fit that being plugged up. Then I would check fuel pressure reading at idle and well off idle and see if it meets spec. If all checks good there then I would look at mechanical binding. Bad wheel bearings, bearings in differentials, transfer case bearings, Ujoints and even transmission issue. These of course have to be isolated from one another and checked and there are ways. For instance to rule out wheel bearings, lift each wheel off the ground individually and see if they spin freely with no bind. If you find one that doesnt move freely then you just have to isolate whether its in the differential or wheel bearing itself.

Right on the money, IMO. If anyone reads my posts they know I believe basics first and narrow down the problem but when asked I will spend other people's money in a heartbeat.

Even during the inspection process you may find a system or part that has a need but has nothing to do with the original complaint.

 

[ladorn45]

OKay got it. I had the fuel filter replaced about 2 years ago, and both front wheel bearing in the last 3 years. The only reason I thought it could be the fuel pump is my gas gauge doesnt work or more accurately jumps around. I will first try the MAF sensor and throttle body. I have not cleaned those since I have owned the car (i know i know im an ******). If that does not solve the issue then i will move on to the other stuff. Also should note this is not a daily driver car so i average about 6k miles if that a year

 

[OR VietVet]

It takes a lot of plugging to clog a fuel filter but also depends on the quality of the fuel you burn thru it. I would get that fuel pressure reading at idle and throttle checked asap. If it does need a pump I ALWAYS recommend a new filter and a new relay at the same time. You would still need to clean or replace the MAF if needed and clean the throttle body. You also need to make sure the plugs and wires are up to *****. "Maintenance pays and breakdowns cost", my dad taught me that. I then learned that maintenance items are recommended over a certain time or mileage to keep operation of the vehicle in the "reliable" window because maintenance items are never designed to repair anything but sometimes those maintenance items will repair a needed FIX.

 

[rockola1971]

OKay got it. I had the fuel filter replaced about 2 years ago, and both front wheel bearing in the last 3 years. The only reason I thought it could be the fuel pump is my gas gauge doesnt work or more accurately jumps around. I will first try the MAF sensor and throttle body. I have not cleaned those since I have owned the car (i know i know im an ******). If that does not solve the issue then i will move on to the other stuff. Also should note this is not a daily driver car so i average about 6k miles if that a year

Other than the fuel pump module containing the sensor that feeds the fuel tank level signal to the fuel gauge, the fuel pump has nothing to do with the fuel gauge. The jumping around could be the fuel level sensor or the stepper motor that the needle is connected to. Its not uncommon at all for those stepper motors to go bad.

 

[Gerry Harvey]

I have there is a lag when the throttle body is sticking. Easy fix by removing breather tube and spraying a solvent ( carb cleaner) and that remove the deposits that's binding the flapper. Manually move the throttle while you spray and wipe up the black residue.

 

[Javie]

Wow its a 2001 with 130k miles on her??!! That's great! Mine is an 02 with 204K miles . Going back to your truck I'm not so sure it's gonna be the throttle body . When at a stop sign do you find the engines idle consistent and steady or does it fluctuate?

 

[ladorn45]

It idles consistent I only notice lag when i start accelerating and sometimes i have to hit the gas a bit more to get power almost as if i am going uphill. Tonight I am going to clean the MAf filter as well as the throttle body. I also have a Autel MaxiDiag MD805 so ill use that to check out the o2 sensors and fuel pressure and see what reading i am getting. Once again I really appreciate everyone help I am learning as i go so you guys are super huge help. Really love this car and doing everything i can to keep it in good shape. I attached a photo of the car a 2001 tahoe with barn doors and third row seatings

 

[OR VietVet]

I did not know they did 3rd row with barn doors. My 2002 has barn doors with no 3rd row. I did learn something new today. I am diggin' the orange color and the black wheels. I am jealous of that look. Trade you. Mine is dark green.

 

[ladorn45]

The car does not come with third row seats but it has all the holes for the brackets so all you have to do is lift the carpet up remove the plastic covering the holes and just buy brackets of ebay from a junk tahoe. Super easy to do and even found matching third row seats for the car.