Numbchux Posted May 25, 2007 Share Posted May 25, 2007 I'm working on an EG33 swap harness for a local guy (into a '95 impreza wagon ). I've got 2 small questions. 1. Fuel pump modulator. What is it. there's a fuel pump signal wire from the ECU. can we just connect this to trip the pump relay. according to my pinout, it just grounds that wire to activate the pump. but according to the diagrams, it goes through this modulator first. AND, again according to the pinout, there's a fuel pump discharge flow control wire which goes to the modulator aswell. it looks like it tells the modulator how much fuel pressure to give.... 2. Vehicle speed sensor. it appears that this sensor is a completely external thing. it's got a 3 wire connector (I wasn't been involved in the removal of the harness...so I don't know where it was plugged into). I appears to have a power wire, a ground, and a signal (which goes to the ECU). can I connect the signal wire to a signal wire in the imp harness....and have it work? Quote Link to comment Share on other sites More sharing options...
GLCraig Posted May 25, 2007 Share Posted May 25, 2007 2. Vehicle speed sensor. it appears that this sensor is a completely external thing. it's got a 3 wire connector (I wasn't been involved in the removal of the harness...so I don't know where it was plugged into). I appears to have a power wire, a ground, and a signal (which goes to the ECU). can I connect the signal wire to a signal wire in the imp harness....and have it work? Most pre OBDII subarus have the VSS mounted to the speedometer, the SVX probabably dose too but I'm not 100% sure. Quote Link to comment Share on other sites More sharing options...
86BRATMAN Posted May 25, 2007 Share Posted May 25, 2007 That sounds like an obd2 eg33 harness. On my mom's 98 it hooks up to a speed sensor that is in the transmission where the cable would be. The 95 Imperza should be the same way, I think. Quote Link to comment Share on other sites More sharing options...
s'ko Posted May 25, 2007 Share Posted May 25, 2007 fuel pump modulator might be for the "POWER" mode for the SVX. If you double tap or accelerate hard on the SVX, the ECU will move the shift points and other fancy stuff to make the car accelerate faster. Might want to go to subaru-svx.net and ask around. BW Quote Link to comment Share on other sites More sharing options...
Numbchux Posted May 25, 2007 Author Share Posted May 25, 2007 the wiring harness is from a '92. and all the diagrams and stuff are for '92. it's OBD I. Most pre OBDII subarus have the VSS mounted to the speedometer, the SVX probabably dose too but I'm not 100% sure. nope, it's a totally separate thing. it appears that the plug for the VSS comes out near the O2 sensors. so it very easily could be on the tranny. fuel pump modulator might be for the "POWER" mode for the SVX. If you double tap or accelerate hard on the SVX' date=' the ECU will move the shift points and other fancy stuff to make the car accelerate faster. Might want to go to subaru-svx.net and ask around. BW[/quote'] the legacy that donated my EJ22e had the same power mode (all 4EATs did, and I think it only moves the shift points), and had no modulator. I just joined subaru-svx, but I need to wait for an admin to approve it. hopefully that'll happen soon. Quote Link to comment Share on other sites More sharing options...
Hocrest Posted May 25, 2007 Share Posted May 25, 2007 The fuel pump modulator is under the rear parcel shelf. There is also a fuel pump resistor back there. On an SVX both items must be wired in a for the fuel pump to work. If your running the Imp or an aftermarket pump, I'm not sure if you'll need them. The VSS is mounted right to the front diff at the same spot that the speedo cable goes to. It is a 3 wire sensor, I've heard that some newere Soobs have a similiar sensor with only two wires. Quote Link to comment Share on other sites More sharing options...
LeoneTurbo Posted April 28, 2012 Share Posted April 28, 2012 Sorry to bring the thread back from the dead, but I have similar swap (also a '92) and don't know what to do with the modulator signal. We've nearly completed the swap. Exhaust is welded up, wiring is done, custom radiator is being made. We already did a - literally - dry run w/o coolant. Engine fired right up but died after 5 secs. Wiring has been done professionally - by me . EG33 harness as 'stand alone' and power feed taken off the GC8 main relay. Specifics: - Neutral switch signal taken from GC8 5MT neutral switch (works, as engines starts) - Park switch signal not connected - SVX fuel pump modulator not connected - Fuel pump relais signal from ECU directly wired to GC8 fuel pump relay (but no power at pump so for initial test pump is wired directly off the battery) - Engine torque control not wired up What could cause the engine to die/cut out after 5 seconds? Quote Link to comment Share on other sites More sharing options...
ivans imports Posted April 28, 2012 Share Posted April 28, 2012 check the feul pump realy did you use stock one or yours also may have a alarm ig kill wire i have a svx here if whant me to check for spsific wire the svx has 2 speed sensors one on spedo head one one back of trans should be very simalar to vss in your car on legacys and outbacks is a green and black wire the svx has a feul temp sensor i belive may be related check the trigger wire for brown ig realy should have a one way diode in line thiss alows power to only go one way did you use the trans ecu? sounds like fun anyway mabee thats what i'll do with the svx i bought for 400 $ bucks yesterday with blown front diff Quote Link to comment Share on other sites More sharing options...
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