2 month problem - No fuel delivery

[Montana]

Which fuel pump to replace?

2005 GT FP is dead, dealer said there are 2 FP in the tank, which one to replace ? passenger or driver side? or maybe the dealer is wrong and there is only 1 at the driver side?

 

[BruceH]

Driver side is the fuel pump. Passenger side pump transfers fuel to the driver side.

 

[JeremyH]

Like said your electrical fuel pump is in the driver side. The passenger side just has a venturi siphon to pull fuel over to the driver side. It is referred to as a jet transfer pump, but it is not really a pump.

 

[Montana]

Like said your electrical fuel pump is in the driver side. The passenger side just has a venturi siphon to pull fuel over to the driver side. It is referred to as a jet transfer pump, but it is not really a pump.

Ok, i just shipped a new FP from the US and it didnt solve my sever fuel problem, this is what i have:

First i am in Beirut/Lebanon i have GT 2005 with 117k on it that was shipped from the US. I have a major problem on acceleration and on WOT with the fuel delivery as shown in the video here:
http://www.youtube.com/watch?v=5pMCJANgKvA

I shipped a new FP and installed it but the problem remains the exact same one.
I sat in the back of the car with a friend driving it and tested the voltage coming to the pump on load, it reached maximum 9V (thats a problem) .

I did some pids logs :
Fuel rail pressure on WOT: fluctuating severely between 0 and 60psi
Fuel pump voltage: between 5-9V maximum (problem)

VOM tests with key on:
TPS showed 5v
FRPS showed 5v
FPDM 12v (i read that it should be 10.5v)
Fuel Pump showed 4v
Battery 13v
ALT 14v (on idle)

Ground test:
12v (no leaks)
10v at the valve cover ground check (is it normal here)

Vacuum test:
no leaks

Inertia switch test passed (i connected the 2 wires and car runs)

New fuel filter, MAF cleaned 2 times, FPRS hose removed it not wet and doent smell fuel.

I logged battery voltage pid and it goes down to 10-11V on load, something is sucking power (here is the problem)

2 days go the problem got worst:
The car now stalls at 3000-3500 RPM it was on 5000-5500 RPM last week.I could reach the rev limit on WOT while car is parked, now i can only reach 3000-3500 RPM
If i floor it slowly in park mode i can reach the rev. limit, if i WOT it fast it stalls on 3000-3500 RPM but engine never shut off.


Changed to a new battery today, no changes.
Changed back to the old Alt. today, (i have a PA 130 amp + 4g wire that i also shipped to my country and it has 4k on it since i bought it) no changes.


Ran a voltage test on battery and PA Alt: 13v on key on, 13.88v on idle, 14.1v on 2000 rpm.
Ran a PCM to FPDM wire test (#12,#21) both wires pass ok.
Ran an FPDM test, 12.66v on idle, voltage fluctuates between 13v & 13.33V on WOT.
Ran a wire directly from FPDM to FP, 12v on key on. / fluctuates between 3v-5v on idle. / fluctuates between 4v and 7v on WOT ---> rpm never reached more than 3500 on WOT<-----
Any ideas what else should i check please?

Thank you.

 

[Montana]

I have a major fuel delivery problem and dunno if you can help me.

First i am in Beirut/Lebanon i have GT 2005 with 117k on it that was shipped from the US. I have a major problem on acceleration and on WOT with the fuel delivery as shown in the video here:

http://www.youtube.com/watch?v=5pMCJANgKvA

I shipped a new FP and installed it but the problem remains the exact same one.
I sat in the back of the car with a friend driving it and tested the voltage coming to the pump on load, it reached maximum 9V (thats a problem) .

I did some pids logs :
Fuel rail pressure on WOT: fluctuating severely between 0 and 60psi
Fuel pump voltage: between 5-9V maximum (problem)

VOM tests with key on:
TPS showed 5v
FRPS showed 5v
FPDM 12v (i read that it should be 10.5v)
Fuel Pump showed 4v
Battery 13v
ALT 14v (on idle)

Ground test:
12v (no leaks)
10v at the valve cover ground check (is it normal here?)

Vacuum test:
no leaks

Inertia switch test passed (i connected the 2 wires and car runs)

New fuel filter, MAF cleaned 2 times, FPRS hose removed it not wet and doesnt smell fuel.

I logged battery voltage pid and it goes down to 10-11V on load, something is sucking power (here is the problem)

2 days go the problem got worst:
The car now stalls at 3000-3500 RPM it was on 5000-5500 RPM last week. I use to reach the rev limit on WOT while car is parked but now i can only reach 3000-3500 RPM.
If i floor it slowly in park mode, i can reach the rev. limit, if i WOT it fast it stalls on 3000-3500 RPM but engine never shut off.


Changed to a new battery today, no changes.
Changed back to the old Alt. today, (i have a PA 130 amp + 4g wire that i also shipped to my country and it has 4k on it since i bought it) no changes.


Ran a voltage test on battery and PA Alt: 13v on key on, 13.88v on idle, 14.1v on 2000 rpm.
Ran a PCM to FPDM wire test (#12,#21) both wires pass ok.
Ran an FPDM test, 12.66v on idle, voltage fluctuates between 13v & 13.33V on WOT.
Ran a wire directly from FPDM to FP, 12v on key on. / fluctuates between 3v-5v on idle. / fluctuates between 4v and 7v on WOT ---> rpm never reached more than 3500 on WOT<-----
Any ideas what else should i check please?

Thank you.

 

[Mustang30212]

Subscribing. Good luck on the fix.

RH

 

[JeremyH]

Sounds like you have tested alot of stuff!

So there is a new pump in the car? 07 or newer?

Throwing any codes?


All these checks look good.

VOM tests with key on:
TPS showed 5v
FRPS showed 5v
FPDM 12v (i read that it should be 10.5v)
Fuel Pump showed 4v
Battery 13v
ALT 14v (on idle)

Based on that Im leaning towards a flow or sensor issue.

 

[lito]

Sensor looks good, I have worked a little with Tony in this, the weird things is that voltage reported by the PCM is all over the place and does not match what the multimeter is reading.

So if anybody has any other ideas it would be good.

 

[JeremyH]

Pcm issue? Seems like an issue between the pcm control and monitor wires to the fpdm. Like the pcm is ordering and its not matching. Not that I have seen a fdpm go bad but maybe swap that out and check.

 

[toorbeenee]

fuel filter, just spoke to my friend he had the same problem ,,,fuel filter was the solution

 

[JeremyH]

Was my initial thought too, but he just replaced it. Maybe its in backwards?

 

[kevinatfms]

im betting its the voltage regulator in the PCM. you need to do a voltage drop test with the IDS to verify a full load through the PCM, not just the alternator. you will get incorrect readings if you just use a DVOM on the alternator. output control of the alternator voltage to the FPDM and pump would be controlled by the PCM during a command on request by the PCM during acceleration.

can you hook up a fuel pressure gauge? dont read the FP_V PID as they are known to be off once in a while and can read as low as 32psi before setting a 1st level fault code.

other than that, if i can read it correctly, you bypassed the inertia switch and it runs good? or it just runs? if you have high resistance in the inertia switch it could be causing voltage/amperage drops to the pump....but it would have to get warm enough to cause that.

have you tried to resistance test your wiring to the FPDM and pump from the fuse box to the pcm to the fpdm and pump? you can have good voltage readings but have high resistance in the wiring....