Bylan

I'm not sure how, but I've ended up with 2 of the most unreliable LS400's ever. The latest failure is on my 1998, I got the dreaded click-no start after stopping at a family friends house for 10 minutes. The car is a newer purchase for me, only had it a month or so, and in that time I have replaced the timing belt/water pump, temperature sensor, and installed a 6month old Lexus dealer battery out of my trusty rusty 1997 LS. I ordered a Denso Remanufactured starter from Amazon, it seemed to be the best middle ground between a $400 brand new unobtanium starter and a total crap no-brand reman. Finished installing it today, and I still get a rapid *click*click*click*click when I attempt to start it. It is not 1 solid click, which my 1997 has done a handful of times in the last 3 years to me (it also always starts the second try), it is a rapid clicking that I'm almost positive is still coming from the starter. I have checked the starter relay, starter fuses (under hood and under the drivers dash), the voltage of the battery (12.65volts), tried a second battery (Toyota brand that came with the car dated 9/18), swapped the starter relay out of my 1997 into the 1998, and I removed a ground on the Drivers side rear of the engine and cleaned it up while I was in there. I also replaced my positive battery terminal with one I had lying around because the original was thoroughly green and corroded, but still showed 12.65volts across the terminal. I did just go watch some youtube videos of 1998-2000 LS's starting up, and I notice the gauge cluster is supposed to go sort of blank when the key is turned to the START position and then spring back to life, however my gauge cluster stays fully lit when I attempt to start, only the Check Engine Light goes out (as its supposed to). I am at my wits end with this and I just don't know what else to try. After the starter replacement, the click is much more rapid. Any advice on what else to throw money, blood, and sweat at, I am all ears. Thanks a lot guys, I would never have been able to enjoy my cars the bit I have without this forum.

Fit1too

Now that's a bummer! Read over this post: http://www.lextreme.com/dx-starter.html It mentions the clicking thing several times.

aptoslexus

Did you examine the battery cables? Sounds like a low voltage situation.
Actually, that's the exact opposite of what mine does. Gauge cluster goes dark during cranking but check engine light stays on. Check engine light goes out when the engine starts.

Bylan

The battery cables, at least the positive cable, does appear rather corroded, definitely not as clean as the cable on my older 1997. The negative cable looks better. Is replacing these cables a major pain in the butt? I've looked around and seen some forum posts from yodaone and others that are avid in this community about quality replacement cables and improving on Lexus's original grounds (apparently they're a bit subpar?) but I haven't seen something on how to replace the cables. I should note I sanded down the ground to the starter itself as well while I was in there, even though it looked perfectly clean and I think all my connections to the starter itself are good.
The gauge cluster seems to be the most offending symptom since it isn't behaving as it should. With the shifter in any other gear than Park or Neutral (where it will allow the car to start) my gauge cluster does go dark with the key to the START position, but of course it doesn't attempt to start the car. The radio and such just restarts, as it would when you start the car in Park or Neutral.
You're saying your cluster goes dark and the CEL light stays on until the engine has fully fired up? Actually thinking about it now I feel my 1997 does the same thing. Dark cluster, CEL on until the engine fires then needles come to life and all warning lights turn off.
Thank you for taking a moment of your time to help a fellow boat owner out. I think I may plug in my OBDII scanner and confirm I have communication to the ECU with the key in the ON position.

aptoslexus

I know you measured voltage across the battery terminals, but did you measure the voltage while cranking? If there's a voltage drop, it should show up.

YODAONE

Did the rebuilt starter work before installation?

Also...see if you can turn crankshaft

Bylan

I admittedly did not go get the new starter bench tested, but I could go get the old one bench tested and confirm the old one had no problems and that would rule out the starter enough for me. The "Old" starter is also a "denso remanufactured for Toyota" and I have service records that it was installed by a local lexus dealer in late 2016. The rapid click I get when attempting to start did become faster and more stable with the new starter, whereas the "old" one clicked somewhat sporadically but still quickly.
I did already rotate the crankshaft a few revolutions. One of my first troubleshooting steps before calling a tow truck, I figured maybe the starter solenoid just needed a slightly different spot on the flywheel to engage, but no dice. One more strange symptom is that the rpm Guage will begin to jump around if I hold the starter for 2-3 seconds, never seen that bizareness before.

fixmiester

Your symptoms are related to a severe voltage drop somewhere in the starter circuit. Because of the location of the solenoid, starter, and connecting cables, it's not easy to eliminate the usual suspects in this car. I'm sure you are aware what causes the "machine gun effect"; when you turn the key to start very little current is required to pull in the solenoid, which then closes the much larger contacts, that provide the really heavy current required by the starter motor. In your case when the starter motor becomes energized, the large current flow drops all the voltage across a point of bad conduction (a poor connection somewhere), then the severe voltage drop causes the solenoid to drop out, disconnecting the starter. As soon as that happens, the current drastically drops, and the voltage go back to normal, so the solenoid energizes again, and quickly repeats the cycle, and so on. This all happens several times per second.

If you can bypass some of the starter motor circuit using large cables (i.e. jumper cables) to take good battery voltage straight to the starter, you can identify the cause rather easily through a process of elimination. HOWEVER, in this car, that's easier said than done. Getting to the solenoid and starter connections in order to bypass some suspected cabling issues requires a lot of contortion and cussing. There are other locations where you can tap in to the circuit, but there are tradeoffs doing that, which may allow Murphy's Law to bite you. Continue searching this forum, and good luck.

Bylan

[QUOTE=fixmiester;10529746]Your symptoms are related to a severe voltage drop somewhere in the starter circuit. Because of the location of the solenoid, starter, and connecting cables, it's not easy to eliminate the usual suspects in this car. I'm sure you are aware what causes the "machine gun effect"; when you turn the key to start very little current is required to pull in the solenoid, which then closes the much larger contacts, that provide the really heavy current required by the starter motor. In your case when the starter motor becomes energized, the large current flow drops all the voltage across a point of bad conduction (a poor connection somewhere), then the severe voltage drop causes the solenoid to drop out, disconnecting the starter. As soon as that happens, the current drastically drops, and the voltage go back to normal, so the solenoid energizes again, and quickly repeats the cycle, and so on. This all happens several times per second.

If you can bypass some of the starter motor circuit using large cables (i.e. jumper cables) to take good battery voltage straight to the starter, you can identify the cause rather easily through a process of elimination. HOWEVER, in this car, that's easier said than done. Getting to the solenoid and starter connections in order to bypass some suspected cabling issues requires a lot of contortion and cussing. There are other locations where you can tap in to the circuit, but there are tradeoffs doing that, which may allow Murphy's Law to bite you. Continue searching this forum, and good luck.[/QUOTTaThT
Thank you fixmiester for the good tidings. And yes I had the same hypothesis for why the solenoid repeatedly energizes but it can't get to that next step and energize the motor. I'm on vacation in Miami for a week or so, so I'm taking a step back from the car and will come at it with full force when I return. My plan is to completely replace the negative battery cable, and I believe I can tap into the starter directly by accessing the underhood fuse box. I'm not totally positive how to do that, but I have read a forum post or 2 outlining it I just need to be certain. At this point I've done the whole timing belt/water pump myself, and the starter myself. After you learn all the pitfalls and know what tools work for the job, it becomes easy. The worst part of the starter is lifting that 40lb intake manifold out, and squeezing it past the motor hangers and junk. Lots of fun but I bet I can have it out in 2-3 hours. I'll of course be updating the forum on my findings, and probably asking for some help.
The dealership would undoubtedly tell me it's the starter and want to replace it to the tune of $900 and I'm thankful this forum has saved me THOUSANDS in repair costs across my 2 ls400s. I'm thankful for those who are willing to spread knowledge and teach rather than tell you to "go to the dealership bro you don't know what you're doing blah blah blah" and dismiss anyone's attempts at learning. Cheers mate, I'll be cruising this boat eventually no matter how busted my knuckles have to get.

oldskewel

iTrader: (1)

Regarding fixmeister's good thoughts on the voltage drop due to a high current draw, that high current will be trying (and failing somewhere) to flow through the big cables between the battery and the starter/solenoid assembly. The little wires will trigger the relay, etc. - don't expect those to be the problem, although they could be affected by the drop in voltage.

What *should* happen when you start is that the gates (starter relay, solenoid) will be opened to allow current to flow through those fat wires. Fat wires will have little resistance and relatively low voltage drop. So almost all of the 12V should drop across the starter itself. If you were to probe those fat cables, you should get close to 12V (like 10V is close) upstream of the starter.

If fixmeister's theory is right, then in your situation, you will not be finding 10V+ immediately upstream of the starter. If you did, and the starter is good, it would be turning. The VOLTAGE is dropping somewhere between the battery positive post and the starter. So probe along that path, at each junction to see where voltage drops. The measurement is only valid when you're actually trying to start. So you need to have your probes in place, probably measuring either 0V or 12V, then have someone turn the key to start, and you take your voltage measurement then.

However, it could also be a failed ground, where the voltage on the back side of the starter actually rises due to a bad ground. Measuring voltage between the battery negative post and the engine (whatever the starter is actually grounded to, measured as closely to the starter as possible) will check for that. Same as measuring on the positive side - you need to do the measurement while the starter is trying to start. Measure from the "ground" point to the battery negative post itself (not the cable). It should be pretty close to zero. If it jumps up while starting, that is a problem.

Bylan

Okey dokey so thread revival. I have been very busy since I came back from my vacation and I was about to tear off the intake manifold again today to diagnose wiring, and for fun I reattached the battery (checking it still has 12.65 volts) and attempted to start the car. IT STARTED. No check engine lights, started it 3 times in a row. It stumbled for a moment on 1st start but it is also low on gas and has been sitting dormant for 2-3 weeks. Now my problem is I just don't know I can trust it. WHY would it start fine after sitting for a few weeks? Could the voltage have just drained out of some faulty part of the electrical system, allowing it to start after reconnecting the battery? I'm really just confused right now, any advice would be hugely appreciated. Im going to refill the coolant, pick up a few gallons of gas to throw in the tank, and bleed the cooling system. If all that goes well I'm gonna take it around the block a few times. My fear is it's going to do this again and require an expensive tow because I didn't change anything. Thanks a lot for all your support on here, I share all the knowledge and troubleshooting I can on here and FB so I appreciate that you all do the same.

peterls

No, replacing the battery cable is no big deal. You don't have to replace the entire cable, you can just replace the end contacts. I did that on mine (finding the right p/n was a bit of a pain I remember), so they are brand new now, and OEM all the way. Highly recommended. And once you screw them to your battery, grease it first with a little Vaseline to prevent corrosion and then screw them on.