unknown throttle problem

[jim01028]

Hi all, I was driving on the freeway today and after about 10 miles I had to put the pedal to the metal just to maintain 70 mph. That was top end and it stayed that way until I got off about 7 miles later. The engine sounded fine and the rpm's were right, so I'm wondering what was going on. It ran fine off the freeway afterwards. Last week it felt like there was a sticking point with the gas pedal around 65 mph, but I could push past it at a normal amount of pedal travel. I usually do my own work, but this has me a bit clueless. Jim

[nos4blood70]

Clogged cat or gunked up throttle body come to mind.

[jim01028]

Clogged cat or gunked up throttle body come to mind.

More likely the throttle body because the car was recently smogged and easily passed

[redzmonte]

Just because the emissions burns clean doesn't mean it isnt restricted.
Check #1
* remove intake arm (Rubber part)
* With the car off
* Press the gas pedal to the floor and check to see if the throttle is all the way open or if it is only opening part way.
----------------------------------
Check #2
* drive to full operating temp
* Check heat with a Laser temp gun on the front of the cat (engine side) to back of cat (Tail pipe side). You should see a 150* +/- raise in temp (Hotter at rear). anything less suggest plugged cat.
-----------------------------------
Check #3
* Replace fuel filter (could be restricting your Volume, but show correct pressure)
* Check fuel pressure while driving should see 45-52PSI. any less and you are might have a bad pump. Schrader valve is on the front of the fuel rail and can hook a gauge there, need a little bit of a long lead to make it up to the windshield.

any other funny things happening? My guess is also the cat..

[jim01028]

Okay thanks, I will try to perform those checks and see what I find.

Just because the emissions burns clean doesn't mean it isnt restricted.
Check #1
* remove intake arm (Rubber part)
* With the car off
* Press the gas pedal to the floor and check to see if the throttle is all the way open or if it is only opening part way.
----------------------------------
Check #2
* drive to full operating temp
* Check heat with a Laser temp gun on the front of the cat (engine side) to back of cat (Tail pipe side). You should see a 150* +/- raise in temp (Hotter at rear). anything less suggest plugged cat.
-----------------------------------
Check #3
* Replace fuel filter (could be restricting your Volume, but show correct pressure)
* Check fuel pressure while driving should see 45-52PSI. any less and you are might have a bad pump. Schrader valve is on the front of the fuel rail and can hook a gauge there, need a little bit of a long lead to make it up to the windshield.

any other funny things happening? My guess is also the cat..