JimWills

I searched the forum and really did not find too much that dealt with the issue I've been having. Truck has been running great, (230,000 miles) and after a nice long drive from NC to FL the throttle response has fallen off. Pressing the accelerator slowly no issue , but passing with a 25% or so additional throttle it acts like the fuel falls off(more moan but no real pickup) . If I release some of the throttle it improves or wait 5-10 seconds it picks back up. I am running a Spectra CIA with a mesh oiled filter. I thing I may have over oiled it and gummed up the MAF Sensor during the 1000 mile drive. Any thoughts or suggestions would be appreciated. I have no codes or CEL and since the intake noise increases it do not think I have a throttle issue.

firehose777

Oiled cotton air filters are notorious for gumming up the maf. I run a K&N myself, but I'm always very careful to not over oil it. It's easy to clean. There's several write ups on it. I've been lucky and never had to mess with mine, but had to help several buddies who thought the filter had to be wet with oil to work. They had similar symptoms.

JimWills

That's what I am hoping, planning to get a can of MAF sensor cleaner tomorrow and see what happens.

joe mcmillan

Get some MAF cleaner and throttle body cleaner. Clean both in about 30 minutes.
Video instructions for the MAF cleaning:

Similar videos available on YouTube for the throttle body also,

JimWills

OK Guys, cleaned the sensor with CRC
MAF sensor cleaner, No improvement.
Throttle body is spotless. Any suggestions? I can't believe its the O2 sensors they will usually throw a code.

screamineagle

Do you still have the stock intake? If so, install it with a fresh oem filter and see if things improve.

08silverbullet

Are you running a custom tune with your CAI? I had some trouble with mine until I got a custom tune

JimWills

Thanks Guys, I can try that when I get back home. The truck has been running fine since I installed it 150,000 miles ago so I cant see what could have changed to cause this. The only other thing I can think of is the throttle position sensor which appears to be totally electronic on these trucks, not a potentiometer.(sp) If the throttle opens and it doesn't sense it properly it wont add fuel until the MAF and/ or the O2 sensors tell the ECM there's more air or the mixture is lean. Not sure how to test that theory though.

joe mcmillan

Try these procedures. No cost - just a few minutes of your time:

----------------------------
This is used for clearing codes by disconnecting the battery cable for 15 mins. Be sure there is no cell phone chargers/lap top/anything like that plugged in. While cables are disconnected I always cycle the key. And turn the head lights on. Then follow it up by the relearn process.

Battery relearn
Because your vehicle’s engine is electronically controlled by a computer,
some control conditions are maintained by power from the battery. When
the battery is disconnected or a new battery is installed, the engine must
relearn its idle and fuel trim strategy for optimum driveability and
performance. Flexible fuel vehicles (FFV) must also relearn the ethanol
content of the fuel for optimum driveability and performance. To begin
this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Release the parking brake. With your foot on the brake pedal and with
the A/C on, put the vehicle in D (Drive) and allow the engine to idle for
at least one minute.
7. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 km) or more to
relearn the idle and fuel trim strategy along with the ethanol content
for flexible fuel vehicles.
• If you do not allow the engine to relearn its idle trim, the idle quality of your vehicle may be adversely affected until the idle trim is
eventually relearned.
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Now that you've cleaned your TB do a TPS reset, it won't hurt a thing and may improve your Throttle response also.
Put Key in the ignition and turn to the ON position, remove the drivers side floor mat, don't start motor, let the bells and chimes do their thing and when they finish push the peddle to the floor and then release the peddle to come back up, turn key to the OFF position, now repeat two more times.
After doing this start the motor and go for a ride and see if it's as good as new!
PS. don't start the motor and floor it, just drive it like you want to keep it!

PerryB

Fuel filter or dying FPDM would be my guess.