LX470 no power when pushing on gas pedal (1 Viewer)

[smwmustang]

ok, so engine oil and AT fluid look good.

My thoughts:
- while in gear: engine RPMs go up, power doesn't end up on tires? --> torque converter?
- while in neutral: RPMs go up properly?
- Have you ever had the feeling on hills/ when towing/ under higher load you don't the acceleration? Would lead me back to the next 3 points
- take out MAF, clean, put back in
- change fuel filter and check
- Fuel pump?

Others:
- Coil packs/ ignition coil... hhmm, should vibrate at lower RPMs right? do you have this?!?
- same behavior in all gears?

So I have driven it the last 2 days for about 50 miles with no further issues. I cannot get it to do what my son said it has done a few times. I drove it pretty hard trying to see what would happen and it drove fine.

I am going to have a shop just take a look at a few things tomorrow just as a precaution and I will change the fuel filter out this weekend as my guess is that it is OEM. No coil pack issues that I can tell and I am familiar with that as that is why we put all new coil packs in about a year ago.

My default is the fuel pump, otherwise it would be the torque convertor going bad but I could not get it to even shift hard or incorrectly. Had it up to about 75 on the interstate and normal driving around town in cool and warmer temps.

You mentioned it had a code for an O2 sensor? Is this past tense or current? Before you said you thought the sensors were old and never replaced. If it was current and you did just replace it that could explain why it’s running correctly for you?

So the O2 code is an ongoing issue since the CATS were stolen. Even with new CATS you can reset the code and it has all new O2 sensors and it eventually throws the check engine light with the same code. It has not really caused any issues other than less MPG but I am having that looked at again tomorrow.

are you sure he wasn't pressing on the brake pedal versus the gas pedal?

Of all my kids, he is the best driver and he helps me work on both of our 100 series trucks. I am pretty sure he had some issues and not due to the wrong pedal. However, I have learned anything is possible but since it has happened a few times my guess is it was not because of his own doing.

 

[Deflagrate]

Just going to throw this out there since it was also intermittent and didn't throw a CEL, but the cruiser got totaled before I solved it. I would occasionally lose power when I was heavier on the throttle. It didn't have to be completely flooring it, but more than I would normally use to accelerate. And by lose power, I mean the engine would basically turn itself off until I let off the gas, then resume running like nothing ever happened. It did this for for the last year or two I had it, but I didn't give it a lot of gas that often, so I didn't encounter it very often. The month or two before it got totaled it seemed like it might be happening at lower amounts of throttle (maybe 50-75%, instead of 75-100%), but I never got to really test this.

Preliminary searches suggested fuel pump (replaced maybe 6-8 years prior) and fusible link/bad electrical connection, and it did start to randomly give me a CEL for the cam position sensor in its last month. Knowing how bad of a job the dealership had done on some previous work, I was guessing they didn't route the CPS wiring correctly, and the belt had worn through the wiring jacket (the same thing happened on some wiring with the driveshaft, except that blew the EFI fuse randomly while driving, how fun). Not sure if the CPS would have been related to the engine dying under throttle though.

 

[smwmustang]

Just going to throw this out there since it was also intermittent and didn't throw a CEL, but the cruiser got totaled before I solved it. I would occasionally lose power when I was heavier on the throttle. It didn't have to be completely flooring it, but more than I would normally use to accelerate. And by lose power, I mean the engine would basically turn itself off until I let off the gas, then resume running like nothing ever happened. It did this for for the last year or two I had it, but I didn't give it a lot of gas that often, so I didn't encounter it very often. The month or two before it got totaled it seemed like it might be happening at lower amounts of throttle (maybe 50-75%, instead of 75-100%), but I never got to really test this.

Preliminary searches suggested fuel pump (replaced maybe 6-8 years prior) and fusible link/bad electrical connection, and it did start to randomly give me a CEL for the cam position sensor in its last month. Knowing how bad of a job the dealership had done on some previous work, I was guessing they didn't route the CPS wiring correctly, and the belt had worn through the wiring jacket (the same thing happened on some wiring with the driveshaft, except that blew the EFI fuse randomly while driving, how fun). Not sure if the CPS would have been related to the engine dying under throttle though.

Good point, I can ask him about full throttle.

 

[kawter]

I had a similar issue - maybe not exact.. but mine was a combo of slack in the throttle cable and a weather-tech floor mat not letting the gas pedal go far enough down.

 

[smwmustang]

I had a similar issue - maybe not exact.. but mine was a combo of slack in the throttle cable and a weather-tech floor mat not letting the gas pedal go far enough down.

I'll check the cable too, we have the same mats and i have put it to the floor with no issues. Still can't make it happen agajn!!

 

[Trollhole]

Get prepared for a throttle body. If he was driving it and it suddenly lost the throttle pedal but you could get it to move somewhat slow but you would have to press the throttle almost all the way down to the floor. Then if you cut the vehicle off and restarted it would go away it's usually the throttle body. It's not cheap. Should have seen more codes than just O2 though.