dostaSC

hey i have a 93 SC400 and the engine wnt crank on it...i have a 1990 Thunderbird and it did the same thing until i replaced to cam sensor. Do you know how or if that is a possible solution to fixing the lexus...the car ran fine until just recently...thanks for the help

Greg

5sp_jzz30

iTrader: (2)

most likely not a sensor. check the main fuse box for the efi fuse and relay. when you turn the key from the acc to start position the efi relay should click. if it does not you have a problem...or at least you found part of it.

dostaSC

ok so when I turn the key it should click and if it doesnt what do i need to be looking for next...could it just be a blown fuse in there?

HellFish

iTrader: (5)

im confused by the title. do you mean that the engine cranks and doesnt fire? or does it not crank at all?

dostaSC

It won't fire...it will spin but that is it. There is no fire to the driver side coil. The security light when locked doesnt come on.

dostaSC

i tried the solution with the EFI fuse. It does click when i turn the key on so thats not a possible problem.

HellFish

iTrader: (5)

couple of things come to mind here. the coil may be the issue. or the crankshaft position (CKP) sensor. camshaft sensor could possibly be another, but more often than not its the CKP.

Steelwheel

a few posts below at https://www.clublexus.com/forums/sho...d.php?t=366142 there was other suggestions, including this one:

If the starter is spinning the motor faster than normal, mine did that and it appeared to be the Main ECU connector. Can't swear by it, but having traced out the possibilities and reading what others posted about this problem, solved it by swapping the ECU. Just decided to clean the connection instead of replacing the ECU and it has worked fine since. Many parts in the electrical/computer world are changed due to simple old connections that need to be cleaned.

I also cleaned the igniter connections at the same time, but it makes more sense that the ECU would have been the culprit.

Also make sure you do a good search here on CL. Odds are someone will have already discussed your exact problem already.

Good Luck,

Tim

dostaSC

ok... i took the car to the local toyota dealer and they said that it was possibly a bad computer. But now i will check the connection like you did. The only problem now is that i dont know where the ECU is located nor how the remove it. Thanks for the reply!

Steelwheel

Using the search tool, you will probably find all kinds of stuff on the main ecu. It is pretty easy to get to under the passenger side carpet directly below the glove box, in a black plastic cover iirc. I also unbolted the ecu from the metal floor and tightened it back securely. Be real careful when fooling around with the connectors that you don't accidentally break anything, and never forget to disconnect the battery negative prior to messing with any of it. If in doubt, let a professional do it. If you really need a new ECU, check the classified section in CL. They should have one at a fair price.

Good Luck,

Tim