My Sc300 Just Died

[dlouis7]

I was driving home one day and it just died. i have the OEM repair manuals and have ohm checked fuel pump,dist., and coil. i have replaced the igniter (with two used ones) from a local yard(150.00) and still no spark. so now i believe it is the ecu but i wanted to get some input from you guys before i shell out another $200.00. Anyone had this problem. Help.

[jzz30]

replace the coil. mine tested ok but it wasnt. i ended up replacing wires, caps, rotors, plugs and still ran funny so i swapped out coils from my LS and it fired right up.

[dlouis7]

replace the coil. mine tested ok but it wasnt. i ended up replacing wires, caps, rotors, plugs and still ran funny so i swapped out coils from my LS and it fired right up.

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I swapped a coil with my buddy the same day i changed the igniter just to be sure and still no start. thanks

[AWJ]

starter solenoid?

[jzz30]

bad ground some where?

[MitchB]

You might have had a crank angle sensor go belly up.

You can likely pull an engine code and find out what died. What year is your car?

[dlouis7]

You might have had a crank angle sensor go belly up. 

You can likely pull an engine code and find out what died.  What year is your car?

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thanks for all the help guys, the car is a 93 it cranks so i was not thinking of a starter sol. problem. i think that ihave checked all the ground connects but i will look harder. i removed all the fuses one by one to check them, while the battery was disconected so this has erased all the codes.(what luck) i do not know to check a crank sensor but according to the wiring schem. it is not in the ignition loop. i would like to know if a computer going bad is a common occurance because i am new to this group (toyota).

[AWJ]

There is no crank sensor on a 1993 2jz ge. Computers can go bad. It's not unheard of. Your distributor button is good? Plug wires are good? You say you've changed a lot of things. Are they installed correctly? Wires on correct cap terminals, distributor aligned properly (this is the equivalent of crank sensor), etc. I have a feeling if you change the computer it still won't start, but hey, it just might. It is extremely difficult to troubleshoot a vehicle over the internet. Good luck.

[MitchB]

Ah, a '93! There is a code for "Loss of Distributor Signal" (or very close to that phrase) on all Toyota motors since at least the mid '80's. "Code 12" on many Toyo engines.

Even if you've pulled the battery and lost codes, just hook it back up and crank it for five to ten seconds. The ECU knows you are turning the key because the Start signal from the ignition switch goes to the starter as well. You should get a distributor code IF that's the problem.

[jzz30]

ooo... i hate code 12, had a problem with that one an a hachi motor swap.

[dlouis7]

well, yesterday i took my computer to a ecu repair facility. The facility advertises on ebay, and lucky for me i live in the general area. when i took it in i had already opened it and did not see any appearant burns. The tech Dave was really cool and he showed me a ton of burns (the solder around a few circuts were not black as i expected to see, Dave explained that when the circuts burned, the way to tell was that the solder was no longer shiny chrome, but was a dull silver because of the acid from the circut). he explained that the number 38 computer was one of his best selling rebuilds. he was even able to look at it and tell me that i was having some minor shifting problems because the part of the computer associated with the automatic trans had a few burns in it also. he feels very confident that the comp is my problem. i got a call today saying it is ready. i will post tomorrow to let everyone know if it starts. thanks everyone.

[jzz30]

hmm so that must mean that something else is wrong resulting in a burnt out computer... i would check on things

[Great-S]

hmm so that must mean that something else is wrong resulting in a burnt out computer... i would check on things

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hey jzz30 can you email me at camry05@aol.com i have a question i need to ask you.thanks

[dlouis7]

well i got the computer back this morning, installed it and......... NO SPARK. i almost fainted. i do not know what is wrong. i also have no fuel but i pulled the pump and ohm checked it and checked it on a 12 volt source, it is good. i also have no check engine light i changed the bulb and still nothing. i have checked all the fuses in the car. under the hood and at the drvs kick panel. i called the local lexus dealership and spoke to a tech, he told me to check the fuel pump ecu i will check that and also B+ to FP at the diagnostic terminal. if this doesnt work i will have to take it in, and at 100.00 an hour it will not be pretty. the problem i am having is, spark is pretty simple if you know which components are involved. from the wiring schem. in the repair manual it would seem that the only components are the coil-igniter-ecu-ignition switch, and they are all good. does anyone know if there is another sensor that the ecu would read in order to signal the igniter.

93 sc300

[jzz30]

there is a way to bypass the fuel pump ecu you have to connect 2 terminals in one of the check connectors if you have the manual it should tell you how to do this, it should be in the EFI section that will run the fuel pump and if you grab the fuel line you should be able to feel the fuel flowing through. also have you checked the ignitor?

[dlouis7]

thanks jzz30 that is what i was making a reference to in my last post (b+ to FP). i tried it and i have found a problem. i have no power in the circuts that power the ecu. i pulled out the trusty repair manual, which by the way is a real lifesaver. those of you out there that do your own work, or try, you have to have one. the tech told me yesterday that i could bypass the pump at the diagnostic terminal under the hood and while i was at it i should check the B+ terminal he said that if i did not have power there the problem was in my harness. the B+ line powers the ecu and the fuel pump ecu. it is run by a main SFI relay i checked the relay and it is good. i just got up and i am preparing to go work on the wire harness. i am not looking forward to it but it is worth 100.00 an hour. i WILL find the cause of the problem today, i have to it is my last day off

[dlouis7]

well, i found the problem. no signal from the ecu terminal #24 it is the terminal that sends 12v to the main sfi relay when the key is turned to the on position. the main relay then closes and allows current to flow to the B+ terminals on the ecu, which in turn powers up everything else. i am going to take the computer back to the rebuilders because the lexus tech that i have been talking to says that it could still be the comp and that he has had to send back a few comps because they were not perfect. just to check everything out i jumped the relay terminals and the car started, and the check engine light is functioning. i drove it for about an hour. the comp. rebuilder really did fix the transmission circuts it feels like a different car. all the shift points are back, and overdrive really kicks in.

[BigD]

well, i found the problem. no signal from the ecu terminal #24 it is the terminal that sends 12v to the main sfi relay when the key is turned to the on position. the main relay then closes and allows current to flow to the B+ terminals on the ecu, which in turn powers up everything else. i am going to take the computer back to the rebuilders because the lexus tech that i have been talking to says that it could still be the comp and that he has had to send back a few comps because they were not perfect. just to check everything out i jumped the relay terminals and the car started, and the check engine light is functioning. i drove it for about an hour. the comp. rebuilder really did fix the transmission circuts it feels like a different car. all the shift points are back, and overdrive really kicks in.

I know this is way old but am hoping you still look here occassionally... I live across the coast from you and would like to know where the computer rebuilder is?

TIA

[VincyRay]

I'm really searching for a solution for my V8 having the same problem. Does anyone out there have the manual that can send me the pages this post mentions? Also, where can I buy the book for myself - I should have done that a long time ago...