Does 95 4R need fuel pump relay mod?
#2
Registered User
In my experience the fuel pump will not turn on with the key if you are using the 3.0 setup.
With the 3.4 relay, it will.
It should not matter as both will work. Saying that, I always have switched to the 3.4 style setup. Simpler IMO
With the 3.4 relay, it will.
It should not matter as both will work. Saying that, I always have switched to the 3.4 style setup. Simpler IMO
#6
I'll go ahead and provide answer to myself....
I was talking to someone about it. He said there's a reason to go through the FC pin and a relay. In the old days when your engine stops, the mechanical fuel pump would stop also especially in case of an accident. Today, we use electrical fuel pump which will continues to pump fuel even when the engine is disable if the key is left on. Apparently, there's some jolt detection which cut the voltage to the relay which turns off the fuel pump as a safety measure in case the fuel line is rupture due to an accident. I guessing that the jolt must be pretty big for it to work because it never did when I 4wheel the truck before. ......
I'll try to make the FC pin to a relay connection to work.
This also explained why some cars can not start after the accident. The ECU has to be reset to deactivate the jolt setting.
I was talking to someone about it. He said there's a reason to go through the FC pin and a relay. In the old days when your engine stops, the mechanical fuel pump would stop also especially in case of an accident. Today, we use electrical fuel pump which will continues to pump fuel even when the engine is disable if the key is left on. Apparently, there's some jolt detection which cut the voltage to the relay which turns off the fuel pump as a safety measure in case the fuel line is rupture due to an accident. I guessing that the jolt must be pretty big for it to work because it never did when I 4wheel the truck before. ......
I'll try to make the FC pin to a relay connection to work.
This also explained why some cars can not start after the accident. The ECU has to be reset to deactivate the jolt setting.
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#9
The fuel pump works now. The FC in 96 T100 wiring is already in the E1-23. I guess the ends must've walked out or something when I plugged the connector in the first time. Same thing with the Coolant temp.
Just from looking at the wiring closer, it seems the FC actually goes to ground to turn on the fuel pump...is that right?
Just from looking at the wiring closer, it seems the FC actually goes to ground to turn on the fuel pump...is that right?
#10
The fuel pump works now. The FC in 96 T100 wiring is already in the E1-23. I guess the ends must've walked out or something when I plugged the connector in the first time. Same thing with the Coolant temp.
Just from looking at the wiring closer, it seems the FC actually goes to ground to turn on the fuel pump...is that right?
Just from looking at the wiring closer, it seems the FC actually goes to ground to turn on the fuel pump...is that right?
the FC is a ground signal. you can use it to trigger the fuel pump relay
#12
Need help. have 95 4runner 3.0. no power to fuel pump with key in on position. no power to fuel pump jumping B+ to FP. Putting direct 12v to fuel pump lead and the pump is fine. My thoughts [aside from correct diagnosis] is run a 12v lead directly to fuel pump that in only powered up when the key is the 'on' position. Anyone know if there's a danger in doing this? Or if there some other T/S i have not done?
#13
Registered User
Other than if your truck flips/rolls over and the fuel pump is still engaged thus pumping gallons and gallons of fuel everywhere, and then some guy throws a cigarette and ignites the whole thing and thus a busload of nuns happens to be driving by right then and you kill them and the 30 puppies they were taking to the animal shelter!!!!! Jeeezzz! Whats wrong with you??
Seriously dont do that for the above reason without the hyperbole and drama.
Do you have power to the larger blue/yellow?? (Cant remember) wire at the relay when the key is on? If not, find out why. Fuse, something not wired correctly, etc.
From there just hook up the relay. The green lead off the relay will go the FP on your ECM.
Maybe this will help?? About 3/4 down
https://www.yotatech.com/forums/f160...-101-a-239002/
Seriously dont do that for the above reason without the hyperbole and drama.
Do you have power to the larger blue/yellow?? (Cant remember) wire at the relay when the key is on? If not, find out why. Fuse, something not wired correctly, etc.
From there just hook up the relay. The green lead off the relay will go the FP on your ECM.
Maybe this will help?? About 3/4 down
https://www.yotatech.com/forums/f160...-101-a-239002/
#15
Need help. have 95 4runner 3.0. no power to fuel pump with key in on position. no power to fuel pump jumping B+ to FP. Putting direct 12v to fuel pump lead and the pump is fine. My thoughts [aside from correct diagnosis] is run a 12v lead directly to fuel pump that in only powered up when the key is the 'on' position. Anyone know if there's a danger in doing this? Or if there some other T/S i have not done?
#16
There is 12v at B+ with key on. Fuel pump works fine when 12v applied directly [at the pump] so pump is non-issue. there is 12v at FP in the diag box when engine is cranking attempting to start truck. and there is 12v at FP in diag box when truck is running. Does this sound like COR is bad?
#17
There is 12v at B+ with key on. Fuel pump works fine when 12v applied directly [at the pump] so pump is non-issue. there is 12v at FP in the diag box when engine is cranking attempting to start truck. and there is 12v at FP in diag box when truck is running. Does this sound like COR is bad?
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