Crazy Electrical issue with EFI system

Cameroonski · 04-27-2010, 12:25 AM

Yes that was the first thing I checked was the jump between B and Fp. But there isn't power to B in the diagnostic box... so this is what i did today.

I checked power at BATT on the computer, it has 12v. I checked M-REL, it had .08v when it should have 12 (with ignition on). So I ran a long line for the BATT line from the computer to the correct wire on the junction box... making sure EVERTHING else was right... power to relay, to BATT, good ground, whatever was going through that relay i made sure was good. It wasnt working and still no power to M-REL with BATT hooked up like this... so the problem must be M-REL i think.

When i jump power to the side of the relay that goes through the resistor (M-REL side) the car runs and drives but idles up and down and crazy. It actually didnt drive too bad though. I basically hooked a hot wire straight up to the M-REL side of the relay b/c that was what the computer was not doing correctly... i think. so... ECU? I have the privilege of a parts car with a good ECU, it is just a bit of a drive to get there, so i cant exactly just switch them out right now, mabe by the weekend.

Any input? Thanks!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Wrist pin issue -- Was: Ris pen issue	KeelanWiese	MKIII Supra	3	02-13-2010 07:38 PM
Sputtering Issue	gorillaguy8	MKIII Supra	5	02-02-2010 09:52 PM
Overheating issue, searches suggest BHG but i'm not convinced!!!	poboy69	MKIII Supra	8	05-01-2009 05:38 PM
Engine Run-on Issue	gottadiesel	MKIII Supra	1	04-02-2009 07:26 AM
Intermittent Electrical Problems on a ’93 MKIV	gjs_cds	Shops & Part Reviews	0	05-22-2006 02:39 PM

04-27-2010, 12:25 AM	#3
Cameroonski 3" Exhaust Join Date: Dec 2009 Location: Austin, Tx Posts: 68	Yes that was the first thing I checked was the jump between B and Fp. But there isn't power to B in the diagnostic box... so this is what i did today. I checked power at BATT on the computer, it has 12v. I checked M-REL, it had .08v when it should have 12 (with ignition on). So I ran a long line for the BATT line from the computer to the correct wire on the junction box... making sure EVERTHING else was right... power to relay, to BATT, good ground, whatever was going through that relay i made sure was good. It wasnt working and still no power to M-REL with BATT hooked up like this... so the problem must be M-REL i think. When i jump power to the side of the relay that goes through the resistor (M-REL side) the car runs and drives but idles up and down and crazy. It actually didnt drive too bad though. I basically hooked a hot wire straight up to the M-REL side of the relay b/c that was what the computer was not doing correctly... i think. so... ECU? I have the privilege of a parts car with a good ECU, it is just a bit of a drive to get there, so i cant exactly just switch them out right now, mabe by the weekend. Any input? Thanks!