Amorget

I am working on a 1997 LS400 with just over 350k on the clock that my dad just acquired. The ACV valve failed and appeared to be introducing steering fluid into the intake and causing a lot of smoke. We pulled off the power steering pump and replaced it with a rebuilt one and filled the ACV valve with JB Weld. After we got it back together, except the air intake (MAF was not plugged in) we went to flush the power steering fluid has my dad had been filling it with normal power steering fluid and I've read that you need ATF or you will ruin the pump quickly.

So we started it and it fired right up the first time, ran it for a couple seconds and then turned it off. Filled then restarted the engine and it ran for a couple seconds and then died itself. From then on we could only get it to run for a second or less before it would die. By the end it wouldn't even start, it would just turn over. Reassembled the intake thinking that with the MAF off it was causing it some issues and put the battery on a charger. We left the car for the battery to charge but that did nothing. Pulled it back apart and checked for spark on both sides by pulling the two rear spark plugs. They were both soaked in fuel. There was spark at both of them, though I wasn't entirely impressed with the color. Cracked the fuel line and got lots of fuel when we tried to start the car. Out of ideas we tried starter fluid and got nothing. Hooked up the computer to it, no codes. Temp sensors all seemed to be reading correctly, only thing that was at all weird was the reading for the TPS, at no pedal it was 12% and on the floor with was 75%, but I don't fully trust the software I was using.

The only wires I messed with were the ones that run right down beside the PS pump, but that was just to move them to the side to unbolt the pump. There was some "crackling" noise from the wires when I was moving them. Any idea what those wires run to? It sort of looks like to the alternator, but they disappear down near the front of the motor.

So to recap - replaced PS pump, starts the first time but doesn't start and run after that, has fuel, has spark, starter fluid does nothing, no codes.

Anyway have any ideas what could be causing this? I am totally stumped.

Thanks,
Douglas

LScowboyLS

this is normal


I think you are on the right track here


did you have the negative battery cable disconnected when you were working on the car?
and when you were charging the car?

johnnyg66

With 350k on a 97 thats alot. How was it running before you did all that? Check the age and voltage of that battery. This car can be quirky with a bad battery. But with that many miles could be other things too.

Amorget

Any idea what those wires run to? Crank Position Sensor maybe?

My dad actually took off the positive terminal instead of the negative terminal (no idea why he did that...) but the battery was disconnected. While I was charging it I left the battery hooked up.

Amorget

My understanding was that it drove wonderfully before that, I've never personally driven it. The battery is about a year old and seems to be very strong, but that is why I charged it, I know some cars are very sensitive to battery voltage.

LScowboyLS

look at fuel pump relay, circuit opening relay and check all underhood fuses, fuselinks and circuit breakers, and tell Dad it is very important to disconnect the NEG battery cable before working on a car, not the POS

always charge battery with BOTH terminals disconnected on a modern car, your charger does not have the inherent protections of the Toyota charging system circuitry

try disconnecting battery completely from car for a few hours, and use that time to check battery rest voltage and fully inspect battery terminal quality including the joint where the POS terminal disconnects from its cable about 2 inches back, undo that bolt and inspect or just replace, Lexus doesn't like low voltage.

you can test the crank position sensor as well as its wiring to the ECU with a multimeter

do you have the factory service manual?

python

iTrader: (4)

i always disconnect both terminals from the battery when charging

Amorget

Interesting, I've never disconnected the battery on any of my GM vehicles when charging nor ever heard of anyone saying that. I will remember in the future for this car. The battery terminals are perfect, the car had been very well maintained. Both terminals had zero corrosion on them and had been sprayed with the red corrosion inhibitor. I will check the bolts on the POS terminal.

I do not have the factory service manual.

I thought about the immobilizer and we spent a bunch of time locking and unlocking the doors with the key fob. Does the immobilizer not disable the entire starter circuit?

Last night I unplugged the ECM B fuse along with taking the negative terminal off of the battery. When I get home today I will put it all back together and see if it starts. If that doesn't work I'll start with the crank position sensor.

Can someone explain how the ignition system on this car is setup? I see that it has two distributors, two coils, and two "igniters" What exactly do the igniters do? Are they akin to an Ignition Control Module that does the electronic timing advancing? I searched on them and found very little info.

For the fuel pump, at what point should it turn on? I am used to GM where when you turn the key to the On position the pump will prime for a few seconds and then turn off if you haven't started the car. When I was checking for fuel at the fuel line it didn't pressurize until after we attempted to start the car. Is that normal?

Thanks for all the help, every one of my cars is GM and that is basically all I work on. This is the first Lexus/Toyota I have ever touched. The overall engineering on it really solid and anything that isn't seems pretty well documented (like the ACV valve).

timmy0tool

iTrader: (7)

the crackling sound you heard doesn't give me a good feeling. it could be that something was shorting or arching as you were messing with the wires. it could also simply be the aged loom the wires are wrapped in since they are now brittle due to age (most likely as you had the battery disconnected).

i would check your spark. if you weren't impressed with the color, why not change the plugs? then work through the rest of the ignition system.

LScowboyLS

pretty close, the igniters do the actually firing of the coil and are controlled by the ECU, rather than a pickup coil and a reluctor. - the ECU uses the signals from the camshaft position sensors and crank position sensor to determine when to energize the igniters (which are basically large power transistors with big heat sinks)


no, both the ignition timing and the fuel timing are controlled by the ECU


yeah, my bad, was thinking of 98 model which does not disable the starter

Amorget

Spent a little time on it last night and checked the coils. I realized that I could not check the internal resistance because I don't have a voltmeter that reads less than 1 ohm. However, the resistance between the input wires and the main plug wire and that was good on both of them.

I figure I will check the two camshaft sensors and the crank shaft sensor tonight hopefully.

The only thing that I noticed was that when cranking the car to attempt to start it the battery idiot light was one, except when it sort of attempted to start and then the light would turn off. I am thinking I am going to pull the battery out and have it charged and tested at the local O'Reilly Auto Parts.

Amorget

I think I've found my problem.

Had the local O'Reilly charge the battery, it was good, but took a good charge. While messing around with it I found that the positive terminal was sort of jerry-rigged and it had corroded a little. Went to the parts store and grabbed a brass positive marine terminal and put that on, which was an improvement from what it was before. Tried to start it and my wife noticed that the RH side coil was shorting to the block and the wires near it. It was shorting very very quickly, meaning I suspect it isn't a single wire that is bad, but the cap and rotor.

I pulled off the cap and rotor and have attached a picture of it. The end of the rotor doesn't look wonderful, but not that horrible to me. I'd appreciate some feedback as to if anyone thinks that is the issue, or if there might be something else causing the short off of the coil. I checked the resistance on the coil wire and it was 600 ohms, which seems to be ok as they both are about that.

Thanks,
Douglas

Amorget

Replaced the rotor, that didn't help.

Pulled off the back RH side spark plug and wire and turned it over watching the spark. It was for sure arcing off of the coil every time it fired. Really running out of ideas... my dad is off picking up a replacement cap for it to see if that helps.

The car is at least half trying to start sometimes once and awhile, but it never seems to catch.

Amorget

Cap didn't fix it... getting a new coil. After the coil... I don't know...

PureDrifter

iTrader: (10)

no check engine lights at all?

Are you using the original key ffor the car? the '97's were a bit of an odd year as they used an immobilizer and won't run without the a working master or valet key.