I bought this car a month or so ago. It was dropped off at a Lexus dealer for state inspection and then would not start. owner decided not to put more money into it so sold it. The fuel pump needed replaced which was the reason for the no start. I replaced it and still cannot get the car to run properly. I am pulling the last of my hair out trying to get this car running. Any input would be greatly appreciated. I will try to be as complete as possible as to what I have done.
1. I changed the fuel pump and the car ran fine. Drove it for 10-15 miles then got a P0303. Car runs great at higher RPM but misses at an idle.
2. I swapped cylinder 1&3 coils - same result - P0303
3. I swapped cylinder 1&3 plugs - same result - P0303
4. Air filter was dirty so I changed it - same result - P0303
5. I cleaned the MAF - same result - P0303
6. Checked compression - was getting 175-178 PSI on a cold engine test
7. Went to change Cyl 3 Injector and in doing so all the injector pig tails and plugs on the injectors just fell to pieces so I had to replace all 6 injectors with a rebuilt set and repin a new set of connectors to the harness. I also checked for carbon build up and to my surprise it really wasn't bad. Cleaned up what little was there and put the car back together with a new set of gaskets. Fired it up, took a couple tries, corrected a vacuum leak and she started. It revs very well and smooth but misses terribly at an idle and is throwing a code of P0300.

I really could use some suggestions as what to try next. I don't mind throwing parts at it as long as I have some direction.
Thanks
Mike G

 

Did you use an OEM fuel pump? Was the one you changed the one in the fuel tank or the high pressure? Was the fuel filter changed? How old is the gas?

 

It was the pump in the tank which I changed. I did not use an OEM but I did replace the filter. The fuel is about 2 weeks old. I had put Premium fuel in as well as a bottle of injector cleaner thinking that might help the original problem.

 

Does it still show P0300 or just P0303?
Was the compression checked on all cylinders or just B1 Cyl 3.
And to clarify. Sitting in the car looking straight ahead, B1 is the right side. Bank2 is the left side.

Standing at the front, looking at the Engine,
B1 order is 1, 3, 5 from front to back of engine.
B2 order is 2, 4, 6.

So 1 and 3 are the first two cylinders on the left. Are those the ones in question?

Did you see sediment in the tank? It's the #1 pump killer! What brand went back in?

 

Thank you for your reply. The problem has changed from P0303 to a P0300 since I changed the injectors. I did check compression on all B1 cylinders after swapping plugs and coils and averaged 175-178 cold. I did not see any sediment at all in the tank when I changed the pump. I did not use an OEM pump.
the car has been serviced at a Lexus dealer it's entire life. Here are the only major issues I see.
@ 107,000 miles Fuel Pressure sensor Campaign which is to tighten or replace the gasket so I do not know if the sensor has ever been replaced
@ 148,000 miles they changed all 6 plugs and did a top end carbon build up cleaning
@ 201,000 miles car was in for P0305 code and they replace the cylinder 5 plug & coil
@ 203,676 miles is where I got the car in a no start situation. dealer said it had a P0087 low fuel rail pressure, which is why I changed the tank pump.

Yesterday, I rechecked all vacuum lines and looked for any sensors I may have left unplugged. I tried leaving the battery disconnected all day and tried it again when I got home. Car still misses terribly and has no power when trying to accelerate. sometimes it would run OK at higher RPMs and sometimes not.
I am going to start at the beginning and retrace my steps to triple check that I did not miss anything. I guess the next components would be the FP sensor and the HPFP. Any other suggestions would be greatly appreciated.

 

I'd suggest you invest in a couple of tools to aid you diagnostic process. With an Android Phone, download OBD Fusion, in the system or setup list, select add enhanced data pack (something like that), and purchase the Toyota Lexus Scion PID pack for your model year. Go to Amazoo and order an Elm327 Mini Bluetooth Adapter OBD2 adapter.

Total cost is less than $40.
Now log MAF, ignition advance, and long and short term fuel trims. We may add other things but you need to know what its doing right and what its doing wrong.

An example is if the fuel pump can't meet the demand, it will show up in the fuel trims. If the fuel is not being burned, Sensor 1 of Bank 1 or 2 CO2 sensor(s) could be be saturated. Vacuum leaks will also show up in trims and CO2 readings...

Stupid phone refuses to load pictures....

 

Take a look here for some details
https://www.clublexus.com/forums/is-...-pid-pack.html

 

Thank you very much! I will see what information I can gather for information over the weekend.

 

I got a diagnostic report and I will try to attach it. There is a lot of info and I really do not know how to read it so please let me know if something looks out of whack.
Thanks

 

As expected, the fuel trims are off the charts and polar opposites of each other at their limits. My hardship towards giving diagnostic input is that this is idle no load condition and it really helps to see it under load, doing work.

Let me think about what makes sense.

Who did the test and what did they say or suggest?

 

I got the reading from OBD Fusion and the Toyota PID add on as suggested. I could try to drive it and catch a reading before it goes into limp mode if it would help.

 

At a glance, you see cylinder 2 and 4 both show current run time misfires. Are you sure you're working on the correct cylinders? Look at my post on the 17th and perhaps plan on pulling the intake and either swapping in new parts on cylinders 2 and 4. Personally, all new plugs and coils from Denso would be my starting place.

Can you confirm what cylinders you swapped coils on. I.e. standing looking at the engine, the left side B1 or the right side B2. B2 is 2, 4, 6.

 

When I had the P0303 code I swapped cyl 3 with cyl 1, this was the side on the left looking down from the front of the car. Also it is the side not covered but the intake, so the should have been bank 1.
I will pull the intake and start with plugs and coil packs for 2 & 4. It is easy enough and makes sense to start there. I will let you know what the out come in. Thank you so very much for your time and knowledge!

 

2013FSPORT,
It has been a while since I have had time to work on the car. I first changed all six plugs w/DENSO and the 3 coil packs w/DENSO on cyl 2, 4, & 6. Ran the car it missed and threw a codes P0300, P0301, 03 & 05. I pulled the new plugs in those cylinders, (they were a bit carbon fouled that quickly) cleaned them and put 3 more DENSO coil packs on that side, also changed the fuel pressure sensor with a factory Toyota one as well as replaced the HPFP with a used one to see if it would make any difference.

I fired the car back up seemed to run ok for a minute then started missing and had no power. I tried to get it down the drive and out on the road but it went into limp mode and now is throwing a P0304 & 06 code again. I had to walk away before I send this thing to the scrap yard.