no power to fuel pump!!!!

[mk3tattoos]

I tried a brand new relay, no luck there. I also checked the ignition switch wires (white/red-black/orange) under the stering column. There was 11.1v with ignition off and -0.21v with it on.

I realy need some help here guys! Thanks.
I can put the the band aid at the main relay and car runs fine...... But I am not going to leave it like that.

 

[mk3tattoos]

So I just put 12v to the black with with orange stripe that runs into the fuse box by the battery, it is the wire that goes to the main relay, and I heard the relay click. then went in to the car, turned the key to the on position andsaw the safc on, and then started car! Weird!!!!

Anyone?

 

[mattsplat72]

Ground?

 

[3p141592654]

Connecting 12V on the B+ bus will energize all the ECU circuits and cause it to operate, even if the BATT and IGSW circuits are Fubar. You need to confirm 12V on BATT, since your first post said it was 0V and that is a problem. This is my last post on this thread since you seem to ignore any advice I give.

 

[mk3tattoos]

Connecting 12V on the B+ bus will energize all the ECU circuits and cause it to operate, even if the BATT and IGSW circuits are Fubar. You need to confirm 12V on BATT, since your first post said it was 0V and that is a problem. This is my last post on this thread since you seem to ignore any advice I give.

what the hell are you talking about!!!! i did everything you told me....... what ever man, after the relay turned on from me adding the 12v to the wire that controls the main relay (not the b+ wire) it works, and ALL wires have power. drove car for 30min and then let it sit for another 30min and it still started.

kick rocks then!!!!!

 

[IJ.]

Thanks for the good info matt! I have been tattooing non stop since Monday so I have not had to check anything out but tonight I plan on working on it all night!

Can mods move this thread the 1j section......did not think it was going to be a swap issue.

Done.

 

[IJ.]

If you have only 0.04V on your BATT terminal at the ECU then you have found your issue. That should be 12V all the time.

Agreed. The problem is not a relay, so forget about it. Focus on getting 12V to your BATT circuit. Fuse is a good start, as is the connector mentioned above.

I tried a brand new relay, no luck there. I also checked the ignition switch wires (white/red-black/orange) under the stering column. There was 11.1v with ignition off and -0.21v with it on.

I realy need some help here guys! Thanks.
I can put the the band aid at the main relay and car runs fine...... But I am not going to leave it like that.

Connecting 12V on the B+ bus will energize all the ECU circuits and cause it to operate, even if the BATT and IGSW circuits are Fubar. You need to confirm 12V on BATT, since your first post said it was 0V and that is a problem. This is my last post on this thread since you seem to ignore any advice I give.

what the hell are you talking about!!!! i did everything you told me....... what ever man, after the relay turned on from me adding the 12v to the wire that controls the main relay (not the b+ wire) it works, and ALL wires have power. drove car for 30min and then let it sit for another 30min and it still started.

kick rocks then!!!!!

Might want to drop the attitude if you ever expect help here again... :nono:

 

[mk3tattoos]

go ahead and close this thread then.......he is the one that was butt hurt for no reson. i comlpletey had every wire out and was testing everything i could. but im the one not listening.
this is the first person i have even come close to giving an ATTITUDE to. he got short with me so i got short with him. you need to give respect to get it. not talk down to me.

i do apologize for posting with attitude.

 

[mattsplat72]

Just a clam voice here, But the guy posting has taking apart the ecu from the 7m and pretty much did an autopsy on it. I would invest money on his opinion on what is wrong here... Just saying


I still think it is a problem within the body harness. There are only a few connections between the ecu and the body ( fuse box and battery) the rest of the connections are within the engine side of the harness and are irrelevant here.

If It was me I would check all the connections between the ma70 and jza70 harnesses . The may be loose and contacting intermittently. You might be shorting them out. The Batt wire is Black and Yellow on your C1 plug it goes from the ECU to the 15 amp efi fuse. It is not Relayed it is fused.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=47
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=48
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=49

This is the entire path of it. It has to be somewhere here. You are going to have to trace the wires to find out the issue. It is as simple as that.

 

[mk3tattoos]

Just a clam voice here, But the guy posting has taking apart the ecu from the 7m and pretty much did an autopsy on it. I would invest money on his opinion on what is wrong here... Just saying

then why not take the new info i posted last (which is a huge finding in the matter) and help me from there. everything checked out on all other ends.

I'm asking myself......what would cause that wire to stop sending power, and were does it end up to send out said power. thats all.

 

[3p141592654]

Lmao

 

[jetjock]

I can sense the clueless even through this little cable. It's why I don't get involved in certain threads...

 

[mk3tattoos]

Ya me to.....lol

By getting the main relay to work, I have 12v at the BATT on the ecu and the b+!
So were do you go from here.
Thanks

 

[jetjock]

If it were me I'd quit trying to do electrical troubleshooting and take up something where critical thinking isn't required. Something requiring much less skill. Tattooing perhaps...

 

[IBoughtASupra]

You jump FP and B+ too see if the pump runs....

 

[mk3tattoos]

You jump FP and B+ too see if the pump runs....

Ya I jumped fp and b+ and fuel pump runs, it sat all night and everything is still fine now. Well kinda..... I know there is an issue some were but I'm to stupid to figure it out, lmao.
Thanks for chiming in

Ya real easy!!! Nice try though jet jock.