jbudi101

Hello Club Lexus!

First of all, hello club Lexus! Been a long time lurker and finally picked up an LS400 last August when an old man ran a light and totaled my MR2 turbo... Bought it from a nice old lady who had dealer records from 1994. I Replaced timing belt, water pump, and put in an optima battery and it's been great for the last 8 months but now I've run into an issue!

Problem

Last night I was driving, and noticed a strongish smell (can't quite put a finger on it, possibly running rich) whilst a tad bit of smoke coming from the tail pipes. At a stop light it hesitated slightly when I gave it gas and the CEL came on for a split second then went off. Drove it for about another 15 minutes without any noticeable problems but I took a right turn and the car shut off completely, didn't hesitate or fumble around. It started right up and when I gave it a little bit of gas it died again after about 20 yards. I repeated this process about 5 times all the while it never hesitated to start. It also didn't feel as if it struggled to stay running but more so just a "switch" off. Put it into the lowest gear as I thought keeping RPMs might keep it alive and it did until I got home (could have just been coincidental and not the lower gear)

Today drove it around and could NOT reproduce what had happened which causes me to think it is electrical. I connected the leads on the OBD but the ecu didn't have any codes saved. Does this sound like ECU capacitor problem? Calling LScowboyLS! I pulled the ECU anyway just to look at the condition of the capacitors and they look pretty good. I know this isn't the best indication since the capacitor internals could be damaged.

My plan is to go to a junk yard tomorrow and find an ECU to put new capacitors in just in case I mess up the first time I'll have a back up. I guess if it doesn't turn out to be the ECU I'll have peace of mind knowing that it is done ... Any input would be great. Thanks in advance.


Just to give you an idea of it's condition.

RA40

iTrader: (6)

They don't necessarily have to be leaking though it is a common sign when they are bad. Yamae can also chime in. One of the symptoms of a failing ECU would be no stored codes. Replacing the caps would be a good move.

The other usual questions:
How many miles on car?
Last tune up? Checking coils, caps, rotors, wires, plugs...

jbudi101

Ah yes. 178K miles and I changed the plugs and wires about 4K miles ago. I'll take a look at the rotors and caps tomorrow.

peterls

I had a similar thing happen to me and it was the idle air control valve (IACV). It is easy to reach, right at the front of the engine next to thermostat.

jbudi101

Oh god I hope not. Why are these $1,000 for our cars? Might as well pull a couple at the while I'm at the yard...

UNCNOR

iTrader: (1)

IACV is $83.09 at Sewall.

python

iTrader: (4)

did u jumper these 2 terminals?
http://www.lexls.com/tutorials/intro/codereading.html

jbudi101

I'm not familiar with Sewall.

Yes I followed this procedure. CEL blinked every .25 seconds.

python

iTrader: (4)

u disconnect the battery for about 5 minutes or remove the efi fuse?

Yamae

I suggest you to measure the ripple voltage as is shown here to know the condition of the ECU simply and easily. Or just simply replace those capacitors. Only 10 dollars investment + DIY can provide you a good extended life of a LS400.

python

iTrader: (4)

its not the money of the capacitors..its the correct gun and know how, if it were as easy as ordering and putting them in i would just do mine as a preventative measure even though my car runs fine..but im not chancing me screwing up the ecu

SkulCracka

check the cam sensor wires the clips holding them on will fail and the wires will rub the belt making the problem intermittent..

python

iTrader: (4)

the code would still be stored

jbudi101

I'll check all of these things and report back once I have any progress or questions. Appreciate the input.