Jlacck

I have a 1998 Ls400 with nearly 300k miles (about 294k miles). Last year I had the transmission rebuilt by a very reputable shop and the engine rebuilt by my mechanic.


However, even prior to getting those items rebuilt, the car was having some imminent issues with starting. Every now and then it would just randomly not start but this was few and far in between (maybe 5 times it wouldn't start from 2013-2016).


Fast forward to now, lately the car is even more inconsistent with not starting. It seems to not start after I've driven the car for a while and then turn it off for 10-20 mins or so. When I come back to the car after 10 or so minutes, it won't start. Yet all of the lights and the electricity in the car works.


Jumping it seems to help get it started, but it takes a long time to jump and even that may not always work. The car would seem to just randomly decide to start after some fiddling around and several attempts to jump.


At that point, the car would run just fine (no issues starting) for the next week or two. Sometimes I'd have no issues for up to a month or so. But then suddenly once again, the same exact no start issues would come back.


I'm starting to think this is an electrical issue because my mechanic has replaced nearly every piece in the engine including battery connectors. The last thing he recently checked was the starter but he says there was nothing wrong with the starter.


My mechanic and I are completely at loss for what the problem could be. But after reading a bit, I'm starting to suspect that the issue may actually be a failing ECM module. I'm curious to know if anybody can shine some light on what I should look at. Are there any "novice" ways of seeing if ECM is going bad?


That said, what would you guys recommend for troubleshooting some common areas that produces starting issues like this. Anybody with any thoughts or questions is welcome to reply. Thanks in advance.

dicer

Clean all electrical connections, grounds, fusible links etc. Yodaone wrote up a good thread on the grounds.

Amskeptic

Remember that a starter can test OK and the windings will just give up later on with ambient engine heat. This happens with any electromagnetic coil, your ignition coils, the fuel pump windings, etc. If the symptom only occurs after driving, it is a possibility. The cure would be a nice new starter.
Colin

Jlacck

I was initially going to have the starter replaced. But when my mechanic went in to change the starter, he found that the connector to the starter was loose and that the starter was actually ok. That said he just tightened up the connector to the starter, but left the starter there. It sounds like you are saying maybe he should have just went ahead and replaced the starter? :-/

Moarpower

So he removed the intake manifold and got down to the starter and didnt replace it? lol...If I did all that id replace it regardless.

lextout

yea i would of replaced the starter too, its a PITA to get
to plus i would of changed other parts, sometimes u gotta get
into the nitty gritty.

Jlacck

I guess he was trying to save me money.

Looks like he'll have to go back in anyway. I'm considering having him replace the alternator as well (although he says there is nothing wrong with it). Everything else in the engine is pretty much new or has been rebuilt. I suppose the starter and the alternator are the only two major pieces that haven't been replaced or changed.

Moarpower

As for testing the ecu, Im not sure if it applies to you but there are threads on here for testing the older models.

Jlacck

So today I got the car to start. After letting it sit all night, I took the battery to the parts store to double check and make sure it wasn't going bad. They said the battery was healthy. So I put it back in the car earlier this evening. It took me about 3 tries and then it started.

I was told that taking the negative off the battery while the car was running is one way to check if the alternator is going bad. So I took off the negative to see if the car would shut down. The car kept running so apparently the alternator is good.

So that brings me back to the starter... Has anyone ever had any experiences where the starter seems to work just fine sometimes and not so well at all in other times? This has been really puzzling for me.

Moarpower

Starters very rarely just stop working in my experience. They will often work intermittently and sometime not work at all.

Leeroy

Something that I recommend you trying, and it may sound dumb, but my car would do the same thing from time to time. If you park on an incline, it seems like the trans will "lock out" and not allow a start of the vehicle, and this is despite all of the factory electronics still functioning properly. On my 2000 LS, when this would happen, I would turn my key to the "on" position and then move the shifter from park to reverse and back to park. Cycle the key, then see if it will now start.