Extreme power loss, random stuttering.

[NikFu S.]

Oh I can imagine. That's is the precise reason I have not yet installed my Walbro, but options are running out. I may have to do it.
No doubt the dealer would overcharge me and on top of a $60 tow. It's somewhat worth the risk.

[NikFu S.]

So I have verified the fuel is not being delivered, something I should have done a week ago. No fuses are blown that I can see, looked at what I could given the conditions of it being outside away from home. Discovered a light in the trunk. Sadly, plugging that in did not solve the problem.

There is 3 clicks under the dash (2 on, 1 off?) when the key is turned on, as always. I'm hoping those are the fuel relays? Even after looking at diagrams I have no idea where they are. Hi-res please?

I spotted the modulator and resistor but do not have the means or the knowledge to test anything. I have little electrical training. It's kind of frustrating to read so many troubleshooting posts that seem to just take that knowledge for granted. Maybe if I get this sorted I will still be able to afford school.

[SoCal LS-L]

Originally Posted by NikFu S.

So I have verified the fuel is not being delivered, something I should have done a week ago. No fuses are blown that I can see, looked at what I could given the conditions of it being outside away from home. Discovered a light in the trunk. Sadly, plugging that in did not solve the problem.

There is 3 clicks under the dash (2 on, 1 off?) when the key is turned on, as always. I'm hoping those are the fuel relays? Even after looking at diagrams I have no idea where they are. Hi-res please?

I spotted the modulator and resistor but do not have the means or the knowledge to test anything. I have little electrical training. It's kind of frustrating to read so many troubleshooting posts that seem to just take that knowledge for granted. Maybe if I get this sorted I will still be able to afford school.

What you should do now is just get to the fuel pump, and test for voltage there. Im not sure which is positive or negative on the harness, but basically you just need to see whether or not any of the wires are getting 12 volts when the key is turned on. Its pretty basic in a 12V system, just clip one of the test leads to ground, and use the other one on each wire... seeing if theres is power going to one momentarily with the key turned on.

This may be solved with just throwing in the new fuel pump, but you need to make sure that the appropriate wire is getting 12V when the key is first turned to prime the pump. This can be done with a $5 walmart multimeter or even a simple test-light.

Basically...

Voltage to pump = Bad pump, throw in yours.

No Voltage = Could be something else electrical. We will tackle that if needed.

So for simplicity, you just need to check if any (or the right one if know which) wire to the fuel pump gets momentary voltage with the key turned on.

[NikFu S.]

I think I used to have a test light but couldnt get it to work.

I think the last time I looked for a multimeter I couldn't find one suitable for adjusting the tps (?) for under 120. At the time I couldn't afford that.
Guess I'll go shell out on my lunch break today.

[NikFu S.]

BTW, s'pose its easiest just to ask, are the relays under the dash those brown and white plugs right near the ecu and if I hear the normal clicks is that coming from them and does that mean they are working?

[kwren]

Originally Posted by NikFu S.

I think I used to have a test light but couldnt get it to work.

I think the last time I looked for a multimeter I couldn't find one suitable for adjusting the tps (?) for under 120. At the time I couldn't afford that.

Do you have Home Depot up there? I got a multimeter a few weeks ago for $4

Keith

[icingdeath88]

Yea $120 is way more than a multimeter usually costs. Look around.

[oab_au]

Originally Posted by SoCal LS-L

What you should do now is just get to the fuel pump, and test for voltage there. Im not sure which is positive or negative on the harness, but basically you just need to see whether or not any of the wires are getting 12 volts when the key is turned on. Its pretty basic in a 12V system, just clip one of the test leads to ground, and use the other one on each wire... seeing if theres is power going to one momentarily with the key turned on.

This may be solved with just throwing in the new fuel pump, but you need to make sure that the appropriate wire is getting 12V when the key is first turned to prime the pump. This can be done with a $5 walmart multimeter or even a simple test-light.

Basically...

Voltage to pump = Bad pump, throw in yours.

No Voltage = Could be something else electrical. We will tackle that if needed.

So for simplicity, you just need to check if any (or the right one if know which) wire to the fuel pump gets momentary voltage with the key turned on.

Just to expand on this. Voltage to pump = Bad pump, throw in yours.

This is not always the case. When you turn the Ign on. The pump gets 12V on the Blue wire, for about 5 seconds You need to check the pump's ground voltage on the Yellow wire. If this wire also has 12V on it, then the pumps modulator under the rear deck is not grounding the pump. To test if this is the problem, put a ground on the Yellow wire, see if the pump will run for the 5 seconds. If it does then you will have to check the connections, and the grounding wire, on the modulator under the rear deck.

Harvey.

[NikFu S.]

Originally Posted by kwren

Do you have Home Depot up there? I got a multimeter a few weeks ago for $4

Keith

I'm there now and I see a battery tester for $4.16, then the range goes up to $149. I wish I knew what I'm looking at.

[NikFu S.]

Alright so i shelled out and bought a Klein MM200. I'm pretty happy with it so far.

I tested the plug at the fuel pump and here is what I got:

Wire | off | on | third relay click

Blue | -# | 12v | drops to 7v, slowly descends
Yellow | 0 | 5v | constant
Gr/Ye | 1v | 52v | constant
Gr/Wh | -# | 12v | constant

For the two negatives I just got a small negative read, between -1 and -2v.

I checked each reading twice, it was the same for each wire both times.

[NikFu S.]

Originally Posted by oab_au

You need to check the pump's ground voltage on the Yellow wire. If this wire also has 12V on it, then the pumps modulator under the rear deck is not grounding the pump.
Harvey.

Ok, so what should the voltage be? Zero with the key on? Because it's 5, which isn't 12.

[oab_au]

Originally Posted by NikFu S.

Ok, so what should the voltage be? Zero with the key on? Because it's 5, which isn't 12.

i guess that those 12V and 5V readings were taken during the 5 seconds that the pump is turned on?
The 5V reading on the yellow, could be either due to the modulator resistance, or a bad connection at the modulator.

The best to do is to, put a ground on the Yellow wire. Take a length of wire, stick one end in the Yellow connector, so that it is connected to the yellow wire, ground the other end, turn the Ign on, see if the pump will run.

Harvey.

[NikFu S.]

How is the pump going to run if the connector is unplugged with a wire poking out of it?

I'm guessing you want me to ground the yellow wire at the modulator end?

I'm completely lost.

[NikFu S.]

Alright so I accessed the rear hatch ceiling (without breaking any clips), unplugged what I believe is the modulator (partially yellow plug), jumped the yellow wire to what I believe was ground, turned the key on and heard a low rumble coming from the pump area for the duration before the 3rd relay click.
There was no fuel burbling/gurgling/fluid movement that I could discern.

I'm not sure if that means it's "running" or not. I suppose there could be some air in the system at the moment. It is depressurized.

How do I "check" the grounding (assuming black) wire on the modulator?

[oab_au]

Originally Posted by NikFu S.

Alright so I accessed the rear hatch ceiling (without breaking any clips), unplugged what I believe is the modulator (partially yellow plug), jumped the yellow wire to what I believe was ground, turned the key on and heard a low rumble coming from the pump area for the duration before the 3rd relay click.
There was no fuel burbling/gurgling/fluid movement that I could discern.

I'm not sure if that means it's "running" or not. I suppose there could be some air in the system at the moment. It is depressurized.

How do I "check" the grounding (assuming black) wire on the modulator?

Well it does sound like it is running.
The yellow wire connects to the resistor and the modulator. The black wire that connects to the resistor is the pump's ground, it is screwed to the body. Make sure the connection to the body is good.
If you want to, you can just ground the yellow wire, and the pump will just run at full output, some do this as a mod.

I would have liked to post a scan of the pumps wiring to help, but the Photo post is not working.

Harvey.