robxs

2008 Is-f with 110,000miles. Zero previous issues.

Today the car stopped in traffic. Tried to restart , the car sounded like it had a bad timing issue / or a few cylinders were not running. Towed the car home.

Trouble shooting .
I am testing the exhaust side camshaft sensor on Bank 1, right hand side, with the bonnet open looking at the engine.
Error codes : P0365 - Camshaft Position Sensor Circuit Bank 1.
Error code : P0368 - I believe this is due to removing the sensor for testing.

Confirmed 5V to Sensor Pin 3 VC2
Confirmed <1ohm to Sensor Pin 1 to E3 26
conformed <1ohn to Sensor Pin 2 to E3 33
also confirmed no short to ground.

Replaced Sensor - no change.

Next step it to purchase a scope to check waveform from ECM

If anyone has had similar issues or a solution , I would be happy to get some help

lobuxracer

iTrader: (2)

short of buying a scope to look at the waveform, I would remove the cover from the ECM and check for continuity to the connector on the sensor from the pin on the circuit board inside to be sure the pin in the ECM connector is actually making contact. I had an ECM pin in my Supra that had an intermittent problem supplying 5v to the throttle position sensors and the MAP sensor because the pin in the connector would pull away when it got below 10C. It was very frustrating to troubleshoot, and I tried nearly everything I could think of to solve the issue including freezing the ECM and throttle sensors, swapping ECMs, swapping throttle position sensors (if anyone needs one, I have a brand new spare from 15 years ago...) only to (after a year of troubleshooting because weather was a factor) find the pin (which passed the continuity check with flying colors) was ever so slightly bent internally and failed to make contact when it was below 10C. I bent the petal inside the pin, replaced the pin in the connector and have never had an issue since.

robxs

Ill buy a scope today and check the waveform., will update later.
Is the IS Gen ECM compatible with the IS-f ? I saw one with a sticker saying it was but thought it unlikely.
Is it possible the timing chain has jumped a cog ? is it difficult to check ? The engine has had an easy life / not much red line stuff.


Thank you for your help

lobuxracer

iTrader: (2)

No the IS F ECM is unique. It is the only V-8, and even the RC F and GS F have different engine management.

robxs

Got scope , Engine cuts out after 6 seconds. Will get a helper to start car tomorrow while i check scope.
At start up event,
1-2 seconds engine starts but appears rough - like a misfire
2-4 cold start sequence ( sounds like air box opens as normal and tone of motor / exhaust changes)
5-6 seconds engine bogs down and cuts out.

Some freeze frame data.
1. Note . MAF appears high to me. ( not sure if normal) Car ran for 6 seconds before cutting out.
2. Misfire on 2 & 8 . Only 1event . Not sure if significant.

Will try to get scope data from start up tomorrow


MAF appears high. Does this mean anything ? Conditions, cold engine, engine has not been started in 1 day.

Misfire on 2 and 8. Not sure if this is normal. Conditions, engine just started and ran for 6 seconds before cut out.

Les7311

“Misfire on 2 and 8”, suggest spark plugs and or coil pack. Pull the easiest one (spark plug) and inspect..

robxs

will check out # 2 in the morning . that would be nice if it is the answer. Thank you , will let you know.

Joe Z

iTrader: (10)

Also did you perform an ECU reset ??

Is that's the case repair with 8 OEM Denso plugs...

Lexus OEM Spark Plug Part number is: 90919-01249
Widely used in the Lexus line up.. and a bit pricey!! AVG $13 Usd each
Denso listed Part Number is: FK20HBR11

If you have a coil pack problem you'll need - 90919-02248

I would only buy the OEM plugs from the dealership or any authorized Denso distributor you trust..

Buyin from cheap online retailers or eBay may result in counterfeit knockoff plugs.
Especially if the price is too good to be true.

Joe Z

robxs

Thanks Joe - really appreciated
ECU reset - ? I disconnected the battery for 5 minutes. If there is a specific procedure let me know.

Les7311

What’s the scooooooppp?

robxs

Oscilloscope to test waveform from ECM / Camshaft Sensor.
This is difficult to do as the car cuts out & does not idle.

TIS procedure

Joe Z

iTrader: (10)

^^ Did an ECU reset not change the status of the CEL ?

I just dealt with:

P0172
P0175
P1170

Which is pointing to a dirty or failing MAF sensor...

Joe Z

robxs

No 2 Spark Plug.

poor condition , plus a small amount of oil on the coil. Will order set and replace. Not sure that this is the issue tho.





ECM


looks like new. No visible burns, pins appear straight, etc on the mother board.

lobuxracer

iTrader: (2)

Coil looks like a disaster. There should be zero oil. Plugs look worn out. Carbon caked on the insulator like that is far from acceptable, the tip + at least 4mm should be clean - or at the very least not caked with carbon deposits.

robxs

I have a set of plugs and a torque wrench on order. Thanks for your expert advise,
Not having inspected plugs before I thought that was normal for 30k . I pulled plug 4. The conductor appears cleaner, the gap also 'appears' smaller. ( bigger on #2, misfire on #2 & #8)
Got a plan & will replace 8 plugs & 1 coil . ETA 2 days.

Thanks for your advise and guidance - really helps

Plug #4 for comparison. there was traces of oil on coil also.


#4