Ls400 Engine Issues

[weiss]

engine light on code P0340 ( camshaft position sensor bank1), loss of power, rough idle, when driving slow the car is fine, but you wanna go a little faster it hesitates and jerks. my mechanic replaced both camshaft sensors and engine cooling temp sensor and i have done the seafoam treatment, but no improvements, engine light still on same code.

[SRK]

Use a timing light to confirm output on the secondary side of both coils. One may have failed - a not uncommon thing with these engines. If you have access to one, an oscilloscope ignition tester would be even better.

Did someone actually advise you that "Seafoam" would correct that problem? I'm amazed at the kind of "faith" placed in that product.

[steve2006]

I looked at the still picture before playing the video and thought that the engine had been fitted 90 degrees out then realised it's a side view.

I would second SRK's opinion regarding the coils it has become a common failure. and listening to the engine it sounds like it's firing on 4 instead of 8,another good clue is to check the cats after a run and see if they are glowing red (be careful this can also damage the cats)

Coils are cheap to replace.

See this post as it was also the coil

http://us.lexusownersclub.com/forums/index.php?showtopic=69809

[jtbel]

I was getting the same code. I replaced the drivers side cam sensor. Also, the coolant temp sensor and the seafoam treatment (just for maintenance purposes). The car runs fine now, but the code still keeps coming up. Might not be related but, during this same time period, I started having to give it gas until the car warms up, then it runs fine. I had replaced the iacv, no change. I'm thinking maybe the temp sensor I installed was junk or maybe an air leak from when I replaced the starter (I did'nt use new intake gaskets). Any other suggestions for the cold start problem would help. Thanks

[rezonans]

I have the same trouble.

Is any solution.

[Bee]

My 96 lexus LS400 is showing the same codep0340 and I changed the camshaft sensor still no change and it's smoking a lil from the engine can someone help me 

 

[paulo57509]

It could be the crankshaft position sensor has failed.  Find it and check its resistance.

These are specs for my '98; I don't know if it apples to your '96.

Resistance (cold): 1,630 - 2,740 ohms

Resistance (hot): 2,065 - 3,225 ohms

Crankshaft position sensors are around $50 (aftermarket) if you just want to throw parts at it.  If you do go this route, ask if you can return the sensor if it's uninstalled.  Compare the resistance of the new vs. existing sensor under the same temperature conditions.

 

Edited July 24, 2020 by paulo57509
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