engine lost power
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
I just got off of work and decided to start up the camry, it started up normal like always, I reved it up and it sounded normal so I took it for a drive and it ran fine. the only thing it's doing now is that it will hiccup once in a while during idle.
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
Follow up because the post above had was not been visible when I signed in today.
I start up the camry yesterday after work and like always it starts up fine but this time it reved up normal so I took it for a drive and no problems. I decided to drive it around some more and the problem came back, lack of power at take off so I floored and it picked up speed and around 50 miles per hour the engine levels out and runs normal at high speeds. a couple of time during take off I did hear a little valve knock but just a little and it went away.
I start up the camry yesterday after work and like always it starts up fine but this time it reved up normal so I took it for a drive and no problems. I decided to drive it around some more and the problem came back, lack of power at take off so I floored and it picked up speed and around 50 miles per hour the engine levels out and runs normal at high speeds. a couple of time during take off I did hear a little valve knock but just a little and it went away.
Last edited by pesnemesis; Feb 6, 2016 at 09:20 AM.
Super Moderator
Joined: Jan 2008
Posts: 15,179
From: PTW
Did you ever check fuel pressure?
A bad ECU would most likely stay bad and not fix itself. Unless an intermediate wiring or connection problem going to it.
Is this problem engine hot or cold.?
A falling O2 sensor can cause acceleration issues. When the problem occurs, disconnect the first O2 sensor on the exhaust coming from the head at its electrical plug and determine if this makes things better.
If after disconnecting the check light is comes on, reconnecting the plug will eventually turn it off but it could a few drives to do so.
Have you check for cracked, damaged vacuum hoses?
A bad ECU would most likely stay bad and not fix itself. Unless an intermediate wiring or connection problem going to it.
Is this problem engine hot or cold.?
A falling O2 sensor can cause acceleration issues. When the problem occurs, disconnect the first O2 sensor on the exhaust coming from the head at its electrical plug and determine if this makes things better.
If after disconnecting the check light is comes on, reconnecting the plug will eventually turn it off but it could a few drives to do so.
Have you check for cracked, damaged vacuum hoses?
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
no I have not checked fuel pressure yet I need to but haven't had a chance to get to the auto parts store. it seems to run great cold but acts up warm. I did spray throttle body cleaner yesterday on the vacuum hoses to check for leaks but found nothing leaking.
Super Moderator
Joined: Jan 2008
Posts: 15,179
From: PTW
Is this a California or federal emissions car?
You stated you changed the temp sensors, did this include the temp sensor for the computer?
Still might check out 02 sensor, its operation is locked out until the coolant temp is hot.
You stated you changed the temp sensors, did this include the temp sensor for the computer?
Still might check out 02 sensor, its operation is locked out until the coolant temp is hot.
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
I did a fuel pressure test and it's normal. I also unplugged the O2 sensor when it started to act up and no change. It's California emissions car.
I drove the car for about 20 miles on the freeway and during acceleration to pick up speed I had throttle up and down to get to speed and when the engine reved up to about 1800 RPMs the engine will run normal. low rpm and warm engine is when I have problems, I checked the AIC and it's clean.
I drove the car for about 20 miles on the freeway and during acceleration to pick up speed I had throttle up and down to get to speed and when the engine reved up to about 1800 RPMs the engine will run normal. low rpm and warm engine is when I have problems, I checked the AIC and it's clean.
Last edited by pesnemesis; Feb 8, 2016 at 08:19 AM.
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
I replaced the coolant temp sensor (2 wires) about 5yrs ago and the TVV(2 vacuum hose connected to this sensor) about 5 months ago.
I have not replaced the temp sending unit (1 wire)
I started up the car this morning and unpluged the coolant temp sensor and the engine rpm dropped I plugged it back in and the engine went back to normal.
I have not replaced the temp sending unit (1 wire)
I started up the car this morning and unpluged the coolant temp sensor and the engine rpm dropped I plugged it back in and the engine went back to normal.
Last edited by pesnemesis; Feb 8, 2016 at 08:21 AM.
Thread Starter
|
Junior Member
Joined: Jan 2016
Posts: 16
From: California
I've been driving the car for a few days and this is what happens on the freeway. I'll throttle the engine quite high then slowly back it off until it starts running normal then I put on cruise control at 65mph but when I drive up a slight elevation change the engine will start to stutter, hiccup... and when the elevation change is gone and the road is level the engine goes back to normal. So a load on the engine is when I have problems.
Last edited by pesnemesis; Feb 16, 2016 at 08:11 PM.
Super Moderator
Joined: Jan 2008
Posts: 15,179
From: PTW
The engine performs normally when under load when coolant temps are low?
The computer shifts the engine between operational modes at a certain coolant temp.
Did you try operating on the road engine warm with the O2 sensor disconnected and then coolant sensor. O2 sensor is locked out coolant cold.
When cold the computer may not use input from all sensors. If the engine performs normally when under load and coolant cold and has problems coolant hot. It could be a bad sensor.
An engine under load also exposes marginal parts. If compression, etc is OK, these tend to be ign or fuel related. Unless bad fuel a plugged fuel filter is rare on this year/model.
If EGR works, try disconnecting the vacuum hose going the modular, plugging the hose and driving when engine hot.
Suggest trying the above then go through ign system with new parts. This is a hit or miss approach but without a diagnostic machine or code output it tends to come down to an educated guess.
The computer shifts the engine between operational modes at a certain coolant temp.
Did you try operating on the road engine warm with the O2 sensor disconnected and then coolant sensor. O2 sensor is locked out coolant cold.
When cold the computer may not use input from all sensors. If the engine performs normally when under load and coolant cold and has problems coolant hot. It could be a bad sensor.
An engine under load also exposes marginal parts. If compression, etc is OK, these tend to be ign or fuel related. Unless bad fuel a plugged fuel filter is rare on this year/model.
If EGR works, try disconnecting the vacuum hose going the modular, plugging the hose and driving when engine hot.
Suggest trying the above then go through ign system with new parts. This is a hit or miss approach but without a diagnostic machine or code output it tends to come down to an educated guess.
