loebco

Hello, I recently sold my SC400 to one of my friends, it has been giving him problems for some time. I came to you guys because I could definitely use some advice.

Long story short, the car will not start unless he turns the ignition to the off position, pulls the efi relay out. Then he must turn the ignition to the on position, reinsert the efi relay, then the car will start.

What could possibly be causing such a thing? I don't even know where to start? Could this be ECU related? Any step in the right direction on behalf of my friend would be infinitely appreciated.

-Thank you in advance,
-Ian

aletz12485

iTrader: (1)

did you, or anyone, find the answer to this problem? Bad ecu? My 93 sc400 is now doing the same thing.

mrmj2u

iTrader: (2)

I spent a lot of time troubleshooting a similar issue. Once I replaced the ECU, the car started immediately. My suggestion would be to start with the ECU. They can be found pretty cheaply on eBay.

aletz12485

iTrader: (1)

That's what I'm about to do. I took mine apart and noticed a bad capacitor. It will work 20% of the time. Otherwise I have to pull the efi relay and then it fires right up. It immediately brings on the cel and then it will start. Sometimes I can turn it off and it will start right back up. Other times, just cranking.

aletz12485

iTrader: (1)

After some further digging into the problem, I don't even have to pull and replace the efi relay for the cel to come on. All I have to do is tap on it and it triggers the cel and starts right up. I swapped the dimmer relay to the efi spot and it does the same thing. Any thoughts? I'm thinking it's wiring related now, and hopefully not the ecu.

mrmj2u

iTrader: (2)

My problem was very similar in that my car would only start if I removed the relay and jumped two of the pins. Otherwise it would not start. New ECU and it fired up immediately.

My my suggestion would be to find an ECU on ebay from
a seller that accepts returns. Pop it in and if the car still doesn't fire up, then return it.

TacMedDoc

Ebay is an option, but so are Tanin if you want a guaranteed rebuild done right.

http://www.taninautoelectronix.com/1...ecu_repair.htm

Hope this helps.

Returd

coupla q's

where is the EFI relay

what's a cel?

mrmj2u

iTrader: (2)

check this thread out

https://www.clublexus.com/forums/per...n-t-start.html

CEL = Check Engine Light