CaveCreek

About two years ago, my RX suddenly ran rough and the CEL came on. I read code P1325, the dreaded IC #6. I started to tackle the job, but got stuck trying to get the throttle body off. I had the RX parked in my extra garage, and put off the repair. I just completed the repair (yes...two years later). I installed six new NGK IFR6T11 laser iridium spark plugs and three BWD E789 ignition coils in the rear. I bolted the throttle body back on, reinstalled the CC cable assembly and PCV valve hose. I changed the oil, but the other fluids all looked okay. Put in a new battery, some gas additive, a K&N air filter, and prayed.

Tried starting the RX and it would not start. The starter is turning the engine over, but the engine will not start. I got a CEL code reader, and it is now giving me code P1760. After trying to start it, it also gives all six ignition coil codes (P1300-1325), but those codes will clear. I got code P0768 from the history, but it also cleared.

The vehicle had a full tank of gas when the problem happened. Do you think it's the gas causing the start problems? Any suggestions?

ArmyofOne

2 year old gas in Arizona? i would start there.

RTIS250

iTrader: (9)

P0768 and P1760 both refer to the transmission.. the first being a shift solenoid and the second being a line pressure control problem.

Did you have the intake manifold removed at any point? If so, make sure you resecured the ground on the back of it. I would retrace all your wires, make sure everything is plugged in. I would also check fuses to make sure nothing blew when you swapped out the battery.

Definitely check on that gas, its likely bad after sitting for so long. Might be able to pull a vacuum line off and spray some starting fluid in, see if it kicks over then...

CaveCreek

I did take the throttle body apart to give me room to change out the rear ignition coils and plugs. I am 99.9% positive I put everything back together correctly following the extensive DIY on the RX300 CL forum. My plan is to siphon old gas and replace with 93 octane. If it still does not crank, I will then start the process of troubleshooting ignition problems.

Will the two transmission-related CEL codes prevent the engine from starting? One other question...I tried to listen for the buzz of the fuel pump with the ignition key in ON, but heard nothing. Should I be able to hear a fuel pump with the key in ON?

CaveCreek

Well...epic fail on the attempt to siphon gas from the tank. I believe there is a "ball valve" at the bottom of the fill tube which prevents the rubber tube from submerging in the gasoline.

Besides taking out the rear seat and accessing the fuel tank from the top, does anyone have any ideas on getting past the "ball valve" to do a simple siphon operation?

mitsuguy

iTrader: (2)

hopefully someone who works on these more often can chime in, but follow a fuel line out of the tank, hopefully before it turns into a hard line, disconnect it and cycle the key to have the fuel pump pump the bad gas out itself...

also, lets clarify

cranking = you can hear the starter turning the motor

so, you have a crank, no start condition????

CaveCreek

mitsuguy,

That was my next planned step as well...disconnect a fuel line from the tank. My concern is that when I turn the ignition to ON, I do not hear any fuel pump hum. I can't remember if the RX fuel pump made a hum as it turned on before.

Also, the engine does turn over. The starter sounds very strong, but it just will not fire. I really want to fix this myself because I know a garage is going to soak me with a bunch of unnecessary stuff.

CaveCreek

Before going further with the fuel issue, I checked for spark. Anyone please correct me if I did this wrong. I removed one of the front ignition coils, inserted a spark plug, and placed the spark plug threads against the engine block. When the engine was turned over, there was no spark at all.

So now I (and others) are thinking that the problem is electrical. I first suspected the engine immobilizer system, since the symptoms are identical to what I have -- engine turns over but will not start. However, when I placed the master key in the ignition, the security system light went out and stayed out. I did the same check with the other master key and the sub key. None of the keys would start the car, but they all made the security light go out.

Unless I am reading wrong, this means the immobilizer is not the problem. Looking for ideas to troubleshoot for no spark -- 2000 RX300.

CaveCreek

Well...it's fixed, and boy do I feel stupid. While looking at photos of where that ground wire was connected behind the PCV hose, I noticed an additional wiring bundle connected to the same bolt. I didn't remember connecting it. Went out to the garage and sure enough--no wire bundle connected. It had fallen down behind the engine where I could not see it. Connected it, cleared the DTCs, and it fired right up. It must have been the power source wiring for the throttle body. Five freakin' days of stress all created by one connection. Geez...

So there you have it boys and girls. When you do any of these fantastic ClubLexus DIYs, take your own pictures of every single thing you disconnect. Then go back through your photo sequence to put it all back together. This could have been fixed the same day I did the repair...if only I had noticed that damn wire connector.

Thanks everyone. Next project is front strut mounts on the 1998 ES300.

RTIS250

iTrader: (9)

If you read my first reply, i mentioned the ground on the intake manifold.

Glad you got it up and running again!