ihiryu

iTrader: (7)

That would make perfect sense. If the CPS isn't working (or intermittently working) then you'd have spark die off since the motor doesn't know when to fire ignition or not. I would replace this first.

Lexus082

It makes sense to me too, except the engine runs fine from a cold start for ten minutes and then stalls. I would think if that was the problem it would cause the same issue(s) all the time. If that is a ground wire which it appears to be, there's no way its grounded at all, its just sitting by itself next to the two other wires from the cam sensor. Thanks ihiryu

Also, I was checking the resistance of the ignition coils and the lexus book states it should be 0.36-0.55 ohms. Both of my ignition coils had a readout of .6 ohms. How strict are these ohm values. Being that mine is .05 ohms out of spec should it be replaced or is that close enough to factory specs?

ihiryu

iTrader: (7)

Pretty strict, remember the hotter it becomes the higher resistance becomes.

Lexus082

Im still working on the car to find the problem. I talked to the mechanic at work (UPS) and he said he wouldn't think it would be a sensor or it would throw a code. So the next couple things I have on my to do list is to replace the fuel filter and bypass the fuel pump ecu. I'm running out of things to check, hopefully I'm getting closer to solving this. The last few items on my list that it could be are coolant temp sensor, ecu, ignition switch, ignition relay, maf sensor and loose wiring.

Update: As of 4am last night I have replaced the following: Spark Plugs, Distributor Caps & Rotors, Igniters, Crankshaft Position Sensor, Fuel Pump, EFI Relay and the Battery. So far I have checked the crankshaft and camshaft position sensors and they all passed the ohm resistance test. However, the primary coil ohm test on each ignition coil is not within specs and is suppose to be .36-.55 ohms (when cold) and they registered in at .6 ohms. According to the lexus shop manuals if they are not within that range they need to be replaced. Once I'm ready to start the engine and keep it running I will ohm each coil again when hot to see how far off the resistance is.

The only other thing I noticed was right next to charcoal canister there is a vacuum hose coming out from the bottom that comes up next to the fender wall of the engine compartment and it looked like something was missing that connected to the end of this vacuum hose. Never really noticed it before...

Lexus082

Just out of curiosity do you guys think its possible or likely it could just be one of the ignition coils failing once it gets warm/hot after driving the car for those first ten minutes from a cold start.

Since both ignition coils were not within specification, I went ahead and replaced those as well. The coils I replaced them with measure .5 ohms. I also had a chance to look at an LS400 and the bare wire that comes off the camshaft position sensor is just an insulator and there isn't anything connected to the end of the wire. So that is no longer a mystery.

Lexus082

I stumbled upon something interesting. The fuel pressure regulator on the driver's side was missing the screw/washer that threads down into the center of the fuel pressure regulator. I was smelling fuel from the regulator. So I may have found the problem... I just finished putting on a new fuel pressure regulator. Im glad i was able to notice this exposed hole in the top of the regulator. Could of easily overlooked it.

But when I pulled off the pcv valve there was a strong fuel odor and from the research I have done it seems that with a bad regulator fuel is allowed to mix in with the oil in the engine. So I'm kind of worried, because I dont know how bad that is.....?

GamblerZ

Does your oil smell like fuel?

2jznosht

The most common problem is trashed piston rings...if your oil level remains the same and your oil gets a stronger and strongerr gas smell youre probably burning oil and its being replaced by gasoline (so the dipstick reading stays the same). Gas will dilute oil and make it too thin to properly protect the engine.

Lexus082

Im pretty sure the gas that is now mixed with the oil is because of the faulty fuel pulsation damper. Now I know why I smelled gas underneath the car when I removed the crankshaft position sensor. This is not good at all. Is changing the oil going to be enough to correct this issue?

I took off the oil cap and it smelled like regular oil, I haven't smelled the dipstick. But im pretty sure it will smell like gas...

GamblerZ

Changing the oil will probably help diagnose if there is an issue.

Lexus082

I smelled the dipstick today and it smelled like oil, so im not sure if its actual fuel that has mixed with the oil or if there is just a strong fuel vapor trapped within the engine crankcase. All I know is it cant be good for the catalytic converters and I plan to change the oil asap.

OilHammer

I had the fuel in the oil issue on a couple of old landcruisers, but it was always caused by the fuel pump itself. On those models the fuel pump was mechanically driven off the cam. If the diaphram inside the pump ruptured, the fuel would run right through the body of the pump and into the block. The smell and resulting problem is unmistakable. If you pull the dipstick, it's beyond full....by a lot. The engine oil reeks of gas, there's no sniffing the dip stick, it's pungent. If you change your oil like this, it will POUR out of the pan and overrun your container pretty quickly.

From the sound of your problem, I would be surprised if fuel in the crankcase was causing the intermittent stalling.

motopunti

I have the stall problem also with my SC400 92, did you find the problem?