SC300 12v Fuel Mod w/ Pictures - FAQ
01-07-08, 09:23 PM
#46
Should I disassemble it and solder or leave it since the car is running fine--- Kinda ( please read more on the bottom ).
At a stop, when I pressed the accelarator at a full throttle, the car runs fast on first gear and once it switches to second gear it is running rich. It is like the fuel lines are rich in fuel.
Also, when I get gas and fill it up and start it, the car dies. I started it again and give it some gas and it will be fine. I just change the fuel pump with Walbro 255. What could be wrong?
Can someone please answer the 2 questions above. This car is a stock 92 SC400.
01-08-08, 01:26 PM
#47
So you are suggesting that it is better to have the wires soldered? I have my Walbro wires crimped with supplied hardwares, I also used a minimal amount of electrical tape and tied them with zip ties.
Should I disassemble it and solder or leave it since the car is running fine--- Kinda ( please read more on the bottom ).
As stated from above, the car is running fine but most of the time, there's a difference.
At a stop, when I pressed the accelarator at a full throttle, the car runs fast on first gear and once it switches to second gear it is running rich. It is like the fuel lines are rich in fuel.
Also, when I get gas and fill it up and start it, the car dies. I started it again and give it some gas and it will be fine. I just change the fuel pump with Walbro 255. What could be wrong?
Can someone please answer the 2 questions above. This car is a stock 92 SC400.
Should I disassemble it and solder or leave it since the car is running fine--- Kinda ( please read more on the bottom ).
As stated from above, the car is running fine but most of the time, there's a difference.
At a stop, when I pressed the accelarator at a full throttle, the car runs fast on first gear and once it switches to second gear it is running rich. It is like the fuel lines are rich in fuel.
Also, when I get gas and fill it up and start it, the car dies. I started it again and give it some gas and it will be fine. I just change the fuel pump with Walbro 255. What could be wrong?
Can someone please answer the 2 questions above. This car is a stock 92 SC400.
As far as why it's running bad, well, lots of things could cause your issue, but one of the potential issues is that the pump is overflowing the demand for fuel once high voltage is applied to it, thus overrunning the ability of the fuel pressure regulator and fuel return line, causing excess pressure in the fuel rail, causing the injectors to flow more than the ecu thinks they are flowing, causing a rich run condition... the only way to tell for sure is to watch fuel pressure as you drive...
04-29-08, 03:18 PM
#49
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I have a stock 92 sc300, when I try to start the engine when it's warm, it will start and then die. I have to start it like 3-4 times sometimes. This mod will fix the problem? Thanks!
05-13-08, 06:14 AM
#50
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.This is where a walbro comes in ,there is no way a supra pump is gonna flow more fuel than a walbro fuel
pump. If this was right then why mostly everyone with supras/boosted sc are running walbros .A smart tuner won,t even touch a car with stock fuel trying to pull 600 hp.
pump. If this was right then why mostly everyone with supras/boosted sc are running walbros .A smart tuner won,t even touch a car with stock fuel trying to pull 600 hp.
good quote regarding QC: "They just up an fail randomly. They start functioning intermittently when stressed. Some just never work right.
I think that when you get a 'good' Walbro, its a good pump. The flipside is that the quality control seems to suck and I'm not the kinda guy who wants to weed out the bad pumps from the good pumps when the fate of my engine hangs in the balance."
Here are a couple of related threads with some good conversation about the benefits of using Denso OEM MKIV Supra TT pumps.
http://www.supraforums.com/forum/sho...t=denso+walbro
http://www.supraforums.com/forum/sho...t=denso+walbro
05-13-08, 06:57 AM
#51
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No, this is absolute crap advice. There is significant backlash against Walbro pumps all over the supraforums because of pump failure and the fact that the Denso oem supra tt pump out flows it.
good quote regarding QC: "They just up an fail randomly. They start functioning intermittently when stressed. Some just never work right.
I think that when you get a 'good' Walbro, its a good pump. The flipside is that the quality control seems to suck and I'm not the kinda guy who wants to weed out the bad pumps from the good pumps when the fate of my engine hangs in the balance."
Here are a couple of related threads with some good conversation about the benefits of using Denso OEM MKIV Supra TT pumps.
http://www.supraforums.com/forum/sho...t=denso+walbro
http://www.supraforums.com/forum/sho...t=denso+walbro
good quote regarding QC: "They just up an fail randomly. They start functioning intermittently when stressed. Some just never work right.
I think that when you get a 'good' Walbro, its a good pump. The flipside is that the quality control seems to suck and I'm not the kinda guy who wants to weed out the bad pumps from the good pumps when the fate of my engine hangs in the balance."
Here are a couple of related threads with some good conversation about the benefits of using Denso OEM MKIV Supra TT pumps.
http://www.supraforums.com/forum/sho...t=denso+walbro
http://www.supraforums.com/forum/sho...t=denso+walbro
Last edited by sc250tt; 05-13-08 at 07:06 AM.
05-13-08, 09:52 AM
#52
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Just an update. It's been almost a year and everything is running great! Gas mileage is still good. No problems at all.
The car hasn't had a hard time starting once!
Thanks,
Michael
The car hasn't had a hard time starting once!
Thanks,
Michael
05-13-08, 03:18 PM
#53
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Crap advice? They do flow better than the Denso pumps .Im using a denso supra pump in my sc .Walbros might flow more but the quality will never be as good as a Denso .FYI my buddy's walbro just failed after 2 months of driving. I dont think the walbro's on ebay are any good .We all know ebay is famous for knockoffs and i bet you those guys on sf got it from ebay.But if you think denso pumps flow better than walbro's then more power to you .
Last edited by dejacky; 05-15-08 at 06:10 PM. Reason: I was off by 1.5 volts, thanks SCoupe
05-13-08, 04:25 PM
#54
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05-13-08, 10:12 PM
#55
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urban myth, fixing something that's not broken. The Denso manufactured oem MKIV TT is one of the top in tank pumps available. Walbros are dicey since they are not meant for the high pressure that a well boosted car requires. Stop promoting them here.
Read KenHenderson of SP Engineering post #3 right here: http://www.supraforums.com/forum/sho...t=denso+walbro
This work from jeff Lucius from links at Supra Forums does not address the fact that these pumps have reliability issues at high pressure: http://www.stealth316.com/2-fuelpumpguide.htm
"The Denso fuel pump 195130-1020 (the Supra Turbo MKIV pump) is one of the best in-tank upgrade choices if you are using injectors up to 550 cc/min and are providing at least 13 volts to the pump. When 18 volts are supplied, the Supra pump is good for injectors up to 880 cc/min. At 13.5 supplied volts no other in-tank pump, except for the R33 Skyline GT-R and A'PEXi BNR32 fuel pumps, flows significantly more fuel up to 70 psi line pressure or 27 psi boost. It is a direct drop-in replacement; all other non-Denso choices require some modification to the fuel pump assembly. It is as quiet as the stock pump. Best of all, it can cost only $180 at Conicelli Toyota. One disadvantage of the Supra pump is its relatively heavy current draw (at 13.5 V, 16A @ 43 psi, 19A @ 70 psi) and large decrease in flow as supplied voltage lowers. Good, heavy-gauge wiring (meaning re-wiring the fuel pump electrical circuit) is a requirement to get the most out of this pump.
The Walbro GSS341 model (also called the 255 lph HP) flows a little less than the Supra Turbo pump up to about 67 psi line pressure (24 psi boost), when 13.5 volts are supplied to both pumps. However, at 12 supplied volts, the Walbro GSS341 outflows the Denso 195130-1020 above 55 psi line pressure (compare John Cribb's Supra pump data to the Walbro charts). Like the Supra fuel pump, the Walbro GSS341 is an excellent choice for 450 cc/min injectors, especially if the fuel pump has not been re-wired (12 supplied volts). Also like the Supra pump, it can be used with up to 610 cc/min injectors if 13.5 volts are supplied, and up to 720 cc/min injectors if at least 16 volts are supplied. The Walbro GSS341 draws about half as much current (at 13.5 V, 8A @ 43 psi, 10A @ 70 psi) as the Supra fuel pump. Some slight modification to the fuel pump assembly is required and it may not be as quiet as the Denso pumps. The price is even less than the Supra pump at $100 to $150."
Read KenHenderson of SP Engineering post #3 right here: http://www.supraforums.com/forum/sho...t=denso+walbro
This work from jeff Lucius from links at Supra Forums does not address the fact that these pumps have reliability issues at high pressure: http://www.stealth316.com/2-fuelpumpguide.htm
"The Denso fuel pump 195130-1020 (the Supra Turbo MKIV pump) is one of the best in-tank upgrade choices if you are using injectors up to 550 cc/min and are providing at least 13 volts to the pump. When 18 volts are supplied, the Supra pump is good for injectors up to 880 cc/min. At 13.5 supplied volts no other in-tank pump, except for the R33 Skyline GT-R and A'PEXi BNR32 fuel pumps, flows significantly more fuel up to 70 psi line pressure or 27 psi boost. It is a direct drop-in replacement; all other non-Denso choices require some modification to the fuel pump assembly. It is as quiet as the stock pump. Best of all, it can cost only $180 at Conicelli Toyota. One disadvantage of the Supra pump is its relatively heavy current draw (at 13.5 V, 16A @ 43 psi, 19A @ 70 psi) and large decrease in flow as supplied voltage lowers. Good, heavy-gauge wiring (meaning re-wiring the fuel pump electrical circuit) is a requirement to get the most out of this pump.
The Walbro GSS341 model (also called the 255 lph HP) flows a little less than the Supra Turbo pump up to about 67 psi line pressure (24 psi boost), when 13.5 volts are supplied to both pumps. However, at 12 supplied volts, the Walbro GSS341 outflows the Denso 195130-1020 above 55 psi line pressure (compare John Cribb's Supra pump data to the Walbro charts). Like the Supra fuel pump, the Walbro GSS341 is an excellent choice for 450 cc/min injectors, especially if the fuel pump has not been re-wired (12 supplied volts). Also like the Supra pump, it can be used with up to 610 cc/min injectors if 13.5 volts are supplied, and up to 720 cc/min injectors if at least 16 volts are supplied. The Walbro GSS341 draws about half as much current (at 13.5 V, 8A @ 43 psi, 10A @ 70 psi) as the Supra fuel pump. Some slight modification to the fuel pump assembly is required and it may not be as quiet as the Denso pumps. The price is even less than the Supra pump at $100 to $150."
Last edited by SCoupe; 05-13-08 at 10:15 PM.
05-14-08, 09:52 AM
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urban myth, fixing something that's not broken. The Denso manufactured oem MKIV TT is one of the top in tank pumps available. Walbros are dicey since they are not meant for the high pressure that a well boosted car requires. Stop promoting them here.
Read KenHenderson of SP Engineering post #3 right here: http://www.supraforums.com/forum/sho...t=denso+walbro
This work from jeff Lucius from links at Supra Forums does not address the fact that these pumps have reliability issues at high pressure: http://www.stealth316.com/2-fuelpumpguide.htm
"The Denso fuel pump 195130-1020 (the Supra Turbo MKIV pump) is one of the best in-tank upgrade choices if you are using injectors up to 550 cc/min and are providing at least 13 volts to the pump. When 18 volts are supplied, the Supra pump is good for injectors up to 880 cc/min. At 13.5 supplied volts no other in-tank pump, except for the R33 Skyline GT-R and A'PEXi BNR32 fuel pumps, flows significantly more fuel up to 70 psi line pressure or 27 psi boost. It is a direct drop-in replacement; all other non-Denso choices require some modification to the fuel pump assembly. It is as quiet as the stock pump. Best of all, it can cost only $180 at Conicelli Toyota. One disadvantage of the Supra pump is its relatively heavy current draw (at 13.5 V, 16A @ 43 psi, 19A @ 70 psi) and large decrease in flow as supplied voltage lowers. Good, heavy-gauge wiring (meaning re-wiring the fuel pump electrical circuit) is a requirement to get the most out of this pump.
The Walbro GSS341 model (also called the 255 lph HP) flows a little less than the Supra Turbo pump up to about 67 psi line pressure (24 psi boost), when 13.5 volts are supplied to both pumps. However, at 12 supplied volts, the Walbro GSS341 outflows the Denso 195130-1020 above 55 psi line pressure (compare John Cribb's Supra pump data to the Walbro charts). Like the Supra fuel pump, the Walbro GSS341 is an excellent choice for 450 cc/min injectors, especially if the fuel pump has not been re-wired (12 supplied volts). Also like the Supra pump, it can be used with up to 610 cc/min injectors if 13.5 volts are supplied, and up to 720 cc/min injectors if at least 16 volts are supplied. The Walbro GSS341 draws about half as much current (at 13.5 V, 8A @ 43 psi, 10A @ 70 psi) as the Supra fuel pump. Some slight modification to the fuel pump assembly is required and it may not be as quiet as the Denso pumps. The price is even less than the Supra pump at $100 to $150."
Read KenHenderson of SP Engineering post #3 right here: http://www.supraforums.com/forum/sho...t=denso+walbro
This work from jeff Lucius from links at Supra Forums does not address the fact that these pumps have reliability issues at high pressure: http://www.stealth316.com/2-fuelpumpguide.htm
"The Denso fuel pump 195130-1020 (the Supra Turbo MKIV pump) is one of the best in-tank upgrade choices if you are using injectors up to 550 cc/min and are providing at least 13 volts to the pump. When 18 volts are supplied, the Supra pump is good for injectors up to 880 cc/min. At 13.5 supplied volts no other in-tank pump, except for the R33 Skyline GT-R and A'PEXi BNR32 fuel pumps, flows significantly more fuel up to 70 psi line pressure or 27 psi boost. It is a direct drop-in replacement; all other non-Denso choices require some modification to the fuel pump assembly. It is as quiet as the stock pump. Best of all, it can cost only $180 at Conicelli Toyota. One disadvantage of the Supra pump is its relatively heavy current draw (at 13.5 V, 16A @ 43 psi, 19A @ 70 psi) and large decrease in flow as supplied voltage lowers. Good, heavy-gauge wiring (meaning re-wiring the fuel pump electrical circuit) is a requirement to get the most out of this pump.
The Walbro GSS341 model (also called the 255 lph HP) flows a little less than the Supra Turbo pump up to about 67 psi line pressure (24 psi boost), when 13.5 volts are supplied to both pumps. However, at 12 supplied volts, the Walbro GSS341 outflows the Denso 195130-1020 above 55 psi line pressure (compare John Cribb's Supra pump data to the Walbro charts). Like the Supra fuel pump, the Walbro GSS341 is an excellent choice for 450 cc/min injectors, especially if the fuel pump has not been re-wired (12 supplied volts). Also like the Supra pump, it can be used with up to 610 cc/min injectors if 13.5 volts are supplied, and up to 720 cc/min injectors if at least 16 volts are supplied. The Walbro GSS341 draws about half as much current (at 13.5 V, 8A @ 43 psi, 10A @ 70 psi) as the Supra fuel pump. Some slight modification to the fuel pump assembly is required and it may not be as quiet as the Denso pumps. The price is even less than the Supra pump at $100 to $150."
I guess toyota just wanted to waste money installing the fuel pump ecu thats why they put it there. You might convince some people that the denso tt pump is better than the walbro but from what ive seen (not what i read on the web) this is how it goes 300zx tt > walbro255 > supratt.
06-28-08, 03:12 PM
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Has anybody had a problem with the fuel pump running even when the key is out of the ignition. We have had a battery drain problem and I was searching around in the trunk heard and little whirring sound and after a little searching figured out it was the fuel pump continuously running. I did the 12v mod about 6+ months ago and up until recently haven't had this issue come up. We even replaced the negative battery cable thinking that may have been the source of the battery drain. Now it appears the fuel pump running continuously may have been the culprit all along. Have any of you who have done the 12v mod had this problem?
06-29-08, 11:44 AM
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Just wondering. Does the fuel pump run for several minutes after the engine is turned off to cool off the fuel rails? Just trying to understand why the fuel pump continues to run and thought there may be some kind of cool down circuit.
07-02-08, 06:52 PM
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just curious, what is the best way to setup the Supra TT in-tank fuel pump so it runs at a constant (and consistant) 14 volts? How does this look?:
Last edited by dejacky; 07-03-08 at 01:43 AM.