2G Auto to manual conversion done, but no power to fuel pump.

[jcurcillo]

I have just completed converting my 98 Spyder GST Auto to AWD manual. Everything is bolted in. The wire harness for the fuel tank has been adapted correctly. I jumped the neutral wire from the auto transmission harness. The car turns over and the starter engages, but I have to power to the fuel pump. I checked the fuel pump relay behind the kick panel on the passenger side. The relay is fine and functions correctly. However, the white/red signal wire that should activate the relay has no voltage. It should have voltage for at least 2 seconds when turning the key. The wire leads back to the ECU harness labeled #8 fuel pump relay according to VFAQ. I have not swapped the auto ECU for a manual ECU. Is there a wire that comes from the TCU that tells the auto ECU it is safe to activate the fuel pump. I would prefer not to swap the ECU for a manual ECU.

 

[mini zilo]

I have not swapped the auto ECU for a manual ECU. Is there a wire that comes from the TCU that tells the auto ECU it is safe to activate the fuel pump. I would prefer not to swap the ECU for a manual ECU.

This is not necessary, as the ECU for a manual and automatic are the same. They are interchangeable between transmission type.

 

[jcurcillo]

This is what I thought and that is why I didn't get a manual ECU. What else would cause my ECU to not send a signal to the fuel pump relay? What conditions must be in place before it will do that?

 

[jcurcillo]

Come on guys. Nobody else has any input?

 

[nongthep]

i need to know too...

 

[luv2rallye]

However, the white/red signal wire that should activate the relay has no voltage. It should have voltage for at least 2 seconds when turning the key.

Do you have spark? On 2g turbos the FP only operates when the ECU senses there is spark. So for example just turning the key to ON will not activate the FP. You should however see +12V on the black/white FP relay wires (pin 4 and 3) with key ON since it comes straight from the ignition switch. If not you have a wiring problem. And with the relay in place you should also see +12V on the white/red (pin 2) since it goes through the relay to pin 4. If not the relay is bad. The relay operates by the ECU grounding the white/red (you can temporarily touch this wire to ground with key on to test the FP relay).

Also on manual trannys the factory Mitsu manual shows ECU pin 91 should be grounded (and disconnect any black/red wire on it from the auto harness). I'm not exactly sure what this does but it may be your problem. Let me know if this fixes anything.

 

[jcurcillo]

I have not tested for spark. I thought that the fuel pump would run for 2 seconds to prime the system regardless of spark or crank angle sensor. I will test it.

I do see 12 volts across the black/white and black/blue wires (pins 2 and 4) when I turn the ignition so I know that is ok.

One thing I am a little confused about. You say the ECU grounds the white/red wire. Dose that mean this wire is +volts at the relay and -volts at the ECU? I have been testing for + at the ECU, but you are saying I should check to see if the ECU is grounding the white/red wire (pin 1 in the relay) and I am getting 12+ from the black/white (pin 3 on the relay). Is this correct?

 

[luv2rallye]

I thought that the fuel pump would run for 2 seconds to prime the system regardless of spark or crank angle sensor.

Not on the 2g turbo (or any 1g) - that is a misconception. Note that to get spark however, the coil, PT, CPS, CAS, starter, and ECU must all be working.

I do see 12 volts across the black/white and black/blue wires (pins 2 and 4) when I turn the ignition so I know that is ok.

We're talking measuring voltage from the test point to ground (which is the norm) so ALWAYS measure this way - not across anything unless stated otherwise. Measuring from the black/white to black/blue (which is pin 1 BTW) proves nothing other than your FP is connected. With key on you should have 12V on pins 2, 3, 4 (white/red, black/white, black/white) - measuring each of these to ground now. Pin 1 (black/blue) only has 12V when the FP relay activates (so FP turns on).

One thing I am a little confused about. You say the ECU grounds the white/red wire. Dose that mean this wire is +volts at the relay and -volts at the ECU? I have been testing for + at the ECU, but you are saying I should check to see if the ECU is grounding the white/red wire (pin 1 in the relay) and I am getting 12+ from the black/white (pin 3 on the relay). Is this correct?

Both ends of the same wire have the same voltage. So +12V at relay pin 2 (white/red) will also be present at ECU pin 8. When the ECU turns the FP off it disconnects pin 8 so the wire "floats" to the +12V that is on the other side of the relay's internal coil which is pin 4 (or +12V). When the ECU turns the FP on it grounds pin 8 which provides the necessary ground the turn on the FP relay (since +12V is on the other side you need a ground on this side to activate or turn on the relay). If the ECU is not grounding pin 8 you will have to figure out why: no spark, bad ECU, broken wire, ECU pin 91 not connected to ground, etc. Obviously if it was grounding it, your FP relay would activate. I would first temporarily touch relay pin 2 (white/red) to ground (with key on) to verify the FP and relay are working. If they are, then proceed to find why ECU is not grounding (or some would say pulling low to ground) pin 8. This all assumes you have spark, for if not, you must fix that first.

 

[jcurcillo]

I got it!!!!!!!!!!!!!

Apparently the fuel pump will not come on when the tank is empty. Well, at least when the ECU thinks the tank is empty. I had the front of the car on jack stands while I was finishing up work to the front end. I had put a little gas in it, but I guess It was not enough. Once I leveled the car out I could hear the pump kick and it started after the fuel system was primed. All this time, I just needed a little more gas. Man I feel like a newbie.

Thanks for all your help.

 

[phaseoneracing]

quick question. i also have a fwd gst spyder auto. i want to change it to manual. how much did you pay for all of the parts that you needed. me and my uncle have a shop. he is a mechanic im a body man. so i will not have to pay for the labor since he will do it.

 

[jcurcillo]

I bought all of the parts off of a guy that worked at a junk yard for $1500. If you just want to convert the car to manual it would be much less.