"Bylan - Hoarder of LS400's" (africantacoman)
06/23/2019 at 21:48 • Filed to: None
1
8|
"Bylan - Hoarder of LS400's" (africantacoman)
06/23/2019 at 21:48 • Filed to: None | 1
| 8 |
I knew the next thing would come, and it has. Sorry if this is lengthy, but I like to be thorough. My newish-to-me 1998 ls400 has exhibited some odd electrical and running issues. For 3 weeks it refused to start, acted like it had a dead battery. I have 2 batteries, both from 2018, one came with the car and is from Toyota and I have a Lexus oem battery for my other LS400. Neither battery would start the car, so I cleaned the negative battery terminal and replaced the thoroughly corroded positive terminal. No change. I checked fuses and stuff, everything seemed fine. Then I went on vacation to Miami for a week, took a break from the non-starting LS, and earlier this week it decided to start up no problems after being disconnected from the battery for 2 weeks. All was well for a few days, then last night after wiping down the engine bay with some degreaser on a microfiber towel and dressing the Underh ood bits with mothers back to black, the car started up with a nasty misfire. The CEL didnt come on for about 5 minutes, and it indicated a misfire on cylinder 6. Checked the coil connector, clean and dry. Let it sit overnight and it started smoothly this morning. On my short drive to work (5 minutes) it began to misfire at a stop light. NO CEL this time , just an intermittent loss of smoothness and idle dropping to 400ish. It only misfired a few times, and only stopped while idling. The radio also cut out for a second, which doesn’t seem misfire related. After work, I let the car idle in my driveway for 10 minutes and it refused to misfire, but it did randomly shut off, as if the key had been removed, but all electronics stayed on. Still no CEL, but it did the same thing the day I got it started as I was topping off and bleeding the coolant, and the CEL did come on; communication interference with the engine immobilizer. That was a weird one, and I did not know what to think of itStarted fine afterward, and i replaced my key fob battery just to rule that out (although my understanding is it uses RFID and the fob battery has nothing to do with that) The door locks also acted funny today, as I was fiddling and testing stuff. What all this adds up to is most likely a failed ecu, so I tore apart my glovebox and fished it out.
That shit is not fun yo. I’ll obviously be checking my spark plugs (of unknown age and mileage) and checking the resistance of the coil packs, but I feel like my car has the infamous failing ecu capacitors that plague even a car that can go 1,000,000 miles (Matt Farah’s is a 96 but basically same thing). The lack of a check engine light just makes no sense to me. Im gonna open up the ecu and inspect it for leakage, if any of you oppos have any tips or troubleshooting ideas im all ears and would love to hear them. Im really glad I have my rusty but trusty 97 LS to drive in the meantime. I might also be getting a job at my local Lexus dealer! So one way or another I’ll get this boat purring like a jaguar. Keep on keepin on y’all!
I like cars: Jim Spanfeller is one ugly motherfucker
> Bylan - Hoarder of LS400's
06/23/2019 at 22:21 |
|
If all the plugs/wires and coil pack are good this screams of ECU problems. The car not running/running after two weeks could be related to capacitors discharging slowly.
Unless this has a distributor (I’m unfamiliar with these cars), in which case, check your cap and rotor.
TheRealBicycleBuck
> Bylan - Hoarder of LS400's
06/23/2019 at 22:53 |
|
Before you go any further, make sure everythi ng is grounded properly. If it was running fine, then started acting strange after you cleaned up the engine bay, you may have gotten some cleaner in the wrong electrical connection or knocked one loose. A friend of mine bought a non-running jeep and got it running by properly grounding the engine block to the frame.
V12 Jake II- New and Improved!
> I like cars: Jim Spanfeller is one ugly motherfucker
06/23/2019 at 23:55 |
|
I know the pre ‘ 98 cars have distributors, idk about the VVT-i engine cars though.
|
Bylan - Hoarder of LS400's
> TheRealBicycleBuck
06/24/2019 at 00:35 |
|
And this was of course my very first thought. Lots of horror stories, especially on the Lexus forums, about people detailing their engine bays and going full-dingus with the pressure washer. I used a chemical guys pump sprayer on its foam setting with a diluted purplepower mix, and only sprayed it on non-electrical areas. I didn’t douse anything and I was methodical about it. There aren’t too many grounds in the engine bay, but now that I think of it there a few on the inner fenderwells that could’ve gotten some drips. I went over a lot of stuff, specifically the coil connectors and injector connectors, with compressed air and nothing was wet hours after I had cleaned it, nor did they show signs of any cleaner getting in or around them . I should mention a random B2797 code popped up when I was topping off the coolant when it first decided to start. The car just shut off and restarted fine. The code is related to the immobilizer communication, and I’m pretty sure the immobilizer is fully integrated into the ecu. The car again today randomly shut off, but had no check engine light or codes, again while idling and getting up to operating temp. Appreciate your response, I'll be going over all the Underwood wiring and doing some jiggle tests if the ecu shows no signs of leakage when I open it up.
|
Bylan - Hoarder of LS400's
> Bylan - Hoarder of LS400's
06/24/2019 at 00:37 |
|
I guess I mentioned the random shut off in my post, but I want it to be clear that happened before cleaning anything
|
Bylan - Hoarder of LS400's
> V12 Jake II- New and Improved!
06/24/2019 at 12:37 |
|
No distributor on the 98s, it’s individual coilpack on spark plugs , all independently controlled by the ecu. And a slow discharge of some failed capacitor is what I suspected when the car decided to start after being away from electricity for 2 weeks
|
V12 Jake II- New and Improved!
> Bylan - Hoarder of LS400's
06/24/2019 at 18:46 |
|
Do you think the low voltage from the slow discharge could have led to the other weird issues? I know when the battery in my S600 was dying there was lots of weird issues that were resolved when I replaced the battery.
|
Bylan - Hoarder of LS400's
> V12 Jake II- New and Improved!
06/24/2019 at 20:01 |
|
I am familiar with what low voltage and alternator issues do to a car with a lot of complex electronics, my 97 exhibited a lot of electrical faults when the ps pump was leaking on the alternator. These issues feel different though, especially having no check engine light for obvious engine faults. And both batteries I’ve tried in the car show healthy voltage, 12.6+ after sitting for like 2 weeks and 14.1+ while running