As I was driving my 92 SC400 down the road yesterday, the engine stalled and afterwards would not start.

The engine code says 25, which is a lean condition.

This morning, I took the battery cable off for 10 minutes to reset the ecu's and still it will not start.

I can hear the engine try to crank, but it will not kick over.

It sounds like it is out of gas, however, there is 3/4 of a tank of fuel left.

I tried to bypass the feul pump ecu, as suggested in this forum, but the engine still did not start.

Here is other possible revelant info.

A few months ago my Traction Control and check engine light came on while I was trying to get up my driveway with two inches of ice on the road. The revs got up pretty high, and the tires were spinning, but the car finally got up the incline.

Since then, those 2 lights have stayed on and the traction control system did not work, otherwise the car drove fine.

However, yesterday the 2 lights went off 1 hour before the engine stalled. I do not know if this is a coincidece or not.

Thanks in advance for any assistance.

TonyC

 

I know you bypassed the fuel pump ecu, but are you able to verify the pump is actually working?
I've never heard of a fuel filter clogging to that extent, but that could cause the stall as well.
Looks like that is your first post- welcome to CL and I'm certain others will soon post other things for you to check, too.

 

I just got back from doing further diagnostics on my SC400 (It is stranded a few miles away from my home).

I found that the fuel pump does not work.

This I discovered by jumping FP & +B, with the ignition on, to see if the little screw poped up. It did not.

I then checked the fuel pump wires in the trunk for voltage, and the ground to continutity. Both were ok.

So I just ordered a new pump for $300 at my local Lexus store. Will be here tomorrow morning. Hopefully after I install it, things will be back to normal.

Thanks for your reply.

TonyC

 

you should have just gotten a walbro for 100.

 

Too late now.

Try to crank?
So does the engine crank or not?
If it's just the fuel pump, the engine should turn over freely.
There just wouldn't be any combustion due to the lack of fuel.

 

Don't forget to check the fuel pump ECU. I've seen a lot of fuel pump ecu goes bad on the early SC. I won't go in detials on this one because seem like you know what you're doing.

 

Let us know how it come out. Like VVT-i said the ecu does goes out on these. I ran into this problem twice.
JPI

 

if you need a fuel pump ecu, i have one 110 shipped.

 

This reminds me of an issue I brought up in the thread below, where I suggest that bypassing the ECU entirely makes for a more reliable car.

https://www.clublexus.com/forums/sho...threadid=27948

According to philauldridge in that thread, the only thing the ECU does is lower the voltage to the fuel pump when it senses conditions that don't require full pressure, but constant full voltage to the pump has no ill effects. If so, bypassing the ECU eliminates a point of failure.

More discussion on bypassing the ECU and instructions for doing so at:

http://www.mkiv.com/techarticles/12v_mod/12v_mod.htm

 

I replaced the feul pump and that solved my starting problem.

My SC400 runs awesome again.

However, my Traction Control light and Check Engine light came back on again, like it has been for the the last several months.

I will attack that problem next weekend.

Thanks for all of the advice.

TonyC