LC J200 4.7 engine loss of power

[Adel75]

Hi All

first want to thank moderator the give me opportunity to register and to be here for receiving support .
i have a LC J200 4.7 L , V8
and I m facing issue with loss of power at full throttle ...diag with Techstream give no error !
what is done :
Full service : engine oil and filter
spark plugs
fuel injectors cleaning

new fuel pump and fuel filter
coils verified for non missfire
fuel tank cleaned

can any one good in diag trouble shooting assist me via TeamViewer ...

i would really appreciate that

regards

Adel

 

[Markuson]

Have you checked the mass air flow sensor and the O2 sensors?

 

[Sandroad]

Also, check over in the 100 series section on Mud. They have the 4.7L and a search there my yield some clues.

 

[bloc]

Do you feel or hear a misfire? Or is it just low on power?

If no misfire I’d be looking at clogged catalysts. Not common, but not unheard of on Toyota’s either.

 

[Adel75]

Have you checked the mass air flow sensor and the O2 sensors?

Hi , Thank u for ur reply ...checked O2 sensors , they are ok , also katakyser was not clogged I inspect it ... For mass airflow what value should he give be reading at idle.?

With kind regards

Adel

 

[Adel75]

Thank u all for the replys ...I will be tracking the air mass flow ...so who know the reading value for it when at idle ...pls share ..I do appreciate ...

Regards

Adel

 

[grinchy]

Maybe try this thread

MAF issue resolved - sudden loss of power

forum.ih8mud.com

 

[Adel75]

Maybe try this thread

MAF issue resolved - sudden loss of power

forum.ih8mud.com

Hi

Thank u for the reply but I do have some difference in my case :

Loss of power when I push throttle to the floor
No missfire
No error in engine and in ETC

Here my actual value of the MAF 5.82 gm/sec ,who can help confirming value is correct or not !?

I would really appreciate

Adel

 

[bloc]

Hi

Thank u for the reply but I do have some difference in my case :

Loss of power when I push throttle to the floor
No missfire
No error in engine and in ETC

Here my actual value of the MAF 5.82 gm/sec ,who can help confirming value is correct or not !?

I would really appreciate

Adel

Hi Adel,

almost no one in this section has your engine in their 200 to help confirm expected values. Otherwise I’m sure you’d find a lot of help.
This is why someone suggested the 100-series section, as in America your engine was in that chassis. They may be a lot better help to you.
Good luck

 

[Adel75]

Hi , ok ...I get it

Thank u all for ur help and support

I will Write again in J100 section

Regards

Adel

 

[TeCKis300]

Hi , Thank u for ur reply ...checked O2 sensors , they are ok , also katakyser was not clogged I inspect it ... For mass airflow what value should he give be reading at idle.?

With kind regards

Adel

I think you're saying that you checked the catalytic converter? The symptoms you're describing without check engine lights are classic clogged catalytic converter symptoms.

A clogged catalytic can itself be a symptom of other things. Bad air fuel ratios, which usually then point at poor closed loop control.

How many miles are on your vehicle? Does it also get poor gas mileage?

O2 sensors can be marginal without tripping the CEL. I'd replace all 4 if your vehicle is higher mileage and these haven't been changed. Check for leaks in the manifold and exhaust, which can skew the feedback loop, causing the engine to run rich (with lower power). None of these will fix a clogged catalytic though, so I'd still inspect that.

 

[Adel75]

I think you're saying that you checked the catalytic converter? The symptoms you're describing without check engine lights are classic clogged catalytic converter symptoms.

A clogged catalytic can itself be a symptom of other things. Bad air fuel ratios, which usually then point at poor closed loop control.

How many miles are on your vehicle? Does it also get poor gas mileage?

O2 sensors can be marginal without tripping the CEL. I'd replace all 4 if your vehicle is higher mileage and these haven't been changed. Check for leaks in the manifold and exhaust, which can skew the feedback loop, causing the engine to run rich (with lower power). None of these will fix a clogged catalytic though, so I'd still inspect that.

Hi

Thank u for the the interest u give to my case
Smoke test Done , no leakage
Car have : 95 K miles
For the Catalytic , I m sure it is not clogged inspected several time
For the O2 , I m thinking to unplug them and try the car
With kind regards

Adel

 

[TeCKis300]

Yes, try unplugging the O2s. You can also unplug the MAF. This should let you see if it's related to closed loop. Reset the ECU by disconnecting the batt to clear the trim maps.

Actually, before you reset, you may want to check the long term fuel trims and see they are significantly skewed?