Changed HG, now starter won't crank? - Page 2

cre · 08-14-2013, 05:08 AM

Of course the CPS would cause a lack of spark.... It's what the computer uses to tell it WHEN to spark and how fast then engine is moving and which piston is ready to fire.

The fuel pump doesn't run if the ECU doesn't see the engine turning. It's a fail safe. On the non-turbo models it's tied into a physical sensor in the air flow meter but on the GTE I believe it's dependent upon a 'valid' signal from the CPS.

thenderson2011 · 08-14-2013, 06:03 PM

Quote:

Originally Posted by cre

Of course the CPS would cause a lack of spark.... It's what the computer uses to tell it WHEN to spark and how fast then engine is moving and which piston is ready to fire.

The fuel pump doesn't run if the ECU doesn't see the engine turning. It's a fail safe. On the non-turbo models it's tied into a physical sensor in the air flow meter but on the GTE I believe it's dependent upon a 'valid' signal from the CPS.

Well my uncle cleaned up the cps wires and now it sparks, could it still be the cps keeping the fuel pump from kicking in? Or is it more likely that I have a bad ground somewhere that I'm overlooking?

cre · 08-16-2013, 04:48 AM

What happened that he has to "clean up" the wiring?

Jumper FP and B+ in the diagnostic box and turn the ignition to "ON". The pump should power up. If not you've got some more wiring issues. That jumper bypasses most of the ignition and emergency fuel cut circuits.

thenderson2011 · 08-19-2013, 04:49 AM

Quote:

Originally Posted by cre

What happened that he has to "clean up" the wiring?

Jumper FP and B+ in the diagnostic box and turn the ignition to "ON". The pump should power up. If not you've got some more wiring issues. That jumper bypasses most of the ignition and emergency fuel cut circuits.

The wire had broken off, and he clipped it and put the wire back in the connector.

I jumped those, and got nothing. What do I need to look into here? I cannot see any more grounds that I've missed, and from here I'm completely stumped.

btwilson86 · 08-19-2013, 05:26 AM

Check to make sure that the fuel pump relay is plugged in to the engine wiring harness. FP relay is on the passenger side fender, next to your strut tower. Also check to make sure that all fuses are good and installed. If I remember correctly, the fuel pump doesn't have a dedicated fuse and it is powered through the 15 AMP EFI fuse in the underhood fuse box. Keep in mind that there are additional fuses and a few relays in the drivers side kick panel to check as well.

Also, if this is a pre 89 Supra or any 87-92 Turbo Supra, make sure that the injector resistor pack on the drivers side fender is plugged in. This won't stop the fuel pump from working, but if it's unplugged you won't get fuel past the injectors and the car still won't run....

thenderson2011 · 08-19-2013, 03:21 PM

Quote:

Originally Posted by btwilson86

Check to make sure that the fuel pump relay is plugged in to the engine wiring harness. FP relay is on the passenger side fender, next to your strut tower. Also check to make sure that all fuses are good and installed. If I remember correctly, the fuel pump doesn't have a dedicated fuse and it is powered through the 15 AMP EFI fuse in the underhood fuse box. Keep in mind that there are additional fuses and a few relays in the drivers side kick panel to check as well.

Also, if this is a pre 89 Supra or any 87-92 Turbo Supra, make sure that the injector resistor pack on the drivers side fender is plugged in. This won't stop the fuel pump from working, but if it's unplugged you won't get fuel past the injectors and the car still won't run....

I ran out and checked, and i couldn't find any relays that were unplugged on the passsenger side by the strut. I just did a quick lookover but couldn't find anything right off. I am going to start checking all my fuses later today when I get home.

08-14-2013, 05:08 AM	#11
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Of course the CPS would cause a lack of spark.... It's what the computer uses to tell it WHEN to spark and how fast then engine is moving and which piston is ready to fire. The fuel pump doesn't run if the ECU doesn't see the engine turning. It's a fail safe. On the non-turbo models it's tied into a physical sensor in the air flow meter but on the GTE I believe it's dependent upon a 'valid' signal from the CPS. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

08-16-2013, 04:48 AM	#13
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	What happened that he has to "clean up" the wiring? Jumper FP and B+ in the diagnostic box and turn the ignition to "ON". The pump should power up. If not you've got some more wiring issues. That jumper bypasses most of the ignition and emergency fuel cut circuits. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

08-19-2013, 05:26 AM	#15
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	Check to make sure that the fuel pump relay is plugged in to the engine wiring harness. FP relay is on the passenger side fender, next to your strut tower. Also check to make sure that all fuses are good and installed. If I remember correctly, the fuel pump doesn't have a dedicated fuse and it is powered through the 15 AMP EFI fuse in the underhood fuse box. Keep in mind that there are additional fuses and a few relays in the drivers side kick panel to check as well. Also, if this is a pre 89 Supra or any 87-92 Turbo Supra, make sure that the injector resistor pack on the drivers side fender is plugged in. This won't stop the fuel pump from working, but if it's unplugged you won't get fuel past the injectors and the car still won't run.... __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

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