PureDrifter

iTrader: (10)

you mentioned you had replaced the ignitors, but did you run the tests indicated in the video that verify the modules as well as the wiring necessary? Were the parts replaced with new or used parts?

It's extremely unusual for the car to not drop codes with a complete failure to spark. What car/where did you source your replacement ECU, and why did you replace it?

Jessicialp

The car isnt throwing a single code! The ecu had a burnt capacitor and was changed out with a new one at the lexus dealership. And so far im rechecking the wiring. I dont know what else it could be

dicer

Jessicialp, I can agree that somethings to do with these cars can be a headache and very difficult to find a solution to.
Since your a diy person, the tool or tools that would be a huge help on this project would be an inexpensive oscilloscope and the correct down loaded shop manual information from the Toyota site I've not done it but its not too costly for a few days of use.
And since everything is related to the ecu and so many things have been changed by you, what you really need as a good starting point is a KNOWN good ecu. I would try the igniter test just to rule that out for sure. I don't know what things are different from 92 that I know more about, and your 93. I know the circuit opening relay is pretty important, and it is located on the outside of the ecu on my cars. I'm surprised Yamae hasn't added some more info here. Really need an ecu from a good running car so that can be ruled out as a problem too. It could be something so simple as a bad wire or a bad connector. If you had the scope you could make sure the ecu is getting the cam and crank signals. Then see if its sending the signals to the igniters and injectors. If not then there has to be a bad sensor or wire or connection.

Another thought, is the timing belt okay? If not that would cause no spark.

plexus914

http://lexus-doc.ru/

Lots of repair manuals in English. Look for:
IG 10 - "IGNITION SYSTEM - ON–VEHICLE INSPECTION" (contains 9 pages)

Good luck!

lextout

why spend money on those parts you replaced, when you could of just went to the dealership and have them diagnose what the problem is for 100$/hour charge max.

Yamae

I'd check the IGT signals from the ECU first and then the IGF signals to the ECU.

I have several more ideas to troubleshoot the no start problems quickly but all of my ideas need an oscilloscope at least as you mention. For those who are not good at using it, my ideas will not be comfortable to perform. But modern computer controlled cars need to use an oscilloscope and the skill to use it in addition to code readings. It is the often case for those who don't use an oscilloscope need to replace parts next to next.

Jessicialp

This is not my car! Im helping a friend! We towed it to lexus, they cant find a problem!

Yamae

It simply means that the problem is something complicated or the mechanic there is not skilled enough. Without an oscilloscope, your problem would not be troubleshooted easily.

dicer

Don't give up on it. Get it going and take it back to the dealer and have the techs come out and see you got it going. They can't fix something a fancy scan tool won't work on. Just spend an hour or two here and there, and study it a bit, as well as help here you'll figure it out.

fixmiester

Let me confirm one thing; are you absolutely certain there is NO spark at the plugs (using a spare plug and hooking one of the plug wires to it while cranking)? If you are sure about that, then you can start looking at the trigger pulses coming from the crank angle sensor; a scope is best, but a digital meter will also show dancing readings of voltage as the engine is cranked: no fluctuation? There's your culprit. OTOH, if pulses are there, then ensure they appear at the igniters, if not, the ECU is suspect, or the immobilizer is holding things off. This is over-simplified, but as a mechanic, I'm sure you understand the logic here. At this point, we don't care about timing, fuel delivery, etc. We just need to get a spark into the cylinders. Let us know what you find.

Steve

dicer

Immobilizer only kills the starter, not the ignition.
And I would hope when someone says no spark, they mean they have pulled the coil secondary wire and checked it at that point. Because if there is spark there and none at the plugs the problem is very obvious.

fixmiester

I'm not sure about a '93, but in my '99 it kills the ignition; last year my wife's key separated and the remote module fell our onto the floorboard, totally unnoticed, until she tried to start it later in the day, and it wouldn't start. I went out there and (using her key), cranked it several times, but it wouldn't start. Out of curiosity I got my key, and it fired right up! That's when I looked at her key more closely, and saw that the remote module was missing. WOW!! Fortunately, I saw it laying beside the accelerator pedal, put it back in, along with a new screw (and a new battery I had handy), and it worked perfectly. So, how many people are aware of this?

dicer

I don't know the 93 either, but figured it was normal gen 1 stuff.

fixmiester

Anyone hear about an LS going over a cliff recently? Don't you love it when we try to help someone, then they disappear, with no feedback?

jaaa

I would bet a good 50% of all posts by first time posters go unresolved long term. It's a shame too, as I've seen some problems on various forums that I would have loved to know what the final resolution was.