Low Fuel Pressure & will not start

[dazwelding]

The engine turns over with only 10 psi fuel psi and will not start. The only code I am getting is P1000, which is the OBD drive cycle testing code since the battery was disconnected for so long. Any ideas on what is the issue? The car has been a project, and this is the first time we are trying to start the car since June of 2014. Here are the details on my fuel system:

Returnless
-8AN fuel line New
Aeromotive filter New
Fore Fuel Hat with GT Pumps, No PPRV New
Black 306 Modified FPDM New
Upgraded power wire for the fuel pumps from Black 306 New
Stock fuel rails
Speedhut Fuel pressure gauge New
Unknown injectors (they are what came on the car- assuming stock)
EGR Deleted New
New gas, 93 with VP octanium

I intend to have the car tuned, but have not got that far yet.

Here are a few things I have tried.
I ran full 12V to the pumps and she put out aprox 70 psi. I put the stock FPDM back in and had no change.

My next thought is to change the fuel rail pressure sensor.

Any advice?

 

[03cobra#2]

What are you running for the MAF and intake setup?

 

[dazwelding]

What are you running for the MAF and intake setup?

Stock MAF, JLT Long CAI (the one that goes into the fender)

 

[DSG2003Mach1]

how long are you letting it crank? with no pprv I usually used key forward to prime twice then it would start relatively quickly, otherwise it took a while.

 

[03cobra#2]

Stock MAF, JLT Long CAI (the one that goes into the fender)

Is it the Cai with the integrated maf housing? Or the intake where the stock housing bolts to it?

 

[dazwelding]

how long are you letting it crank? with no pprv I usually used key forward to prime twice then it would start relatively quickly, otherwise it took a while.

I cranked her until the battery about died, Saturday night, again Sunday morning after the battery recharged, and again Sunday afternoon after the battery recharged. It cranked for quite some time, long enough to build oil pressure and kill the battery.

 

[dazwelding]

Is it the Cai with the integrated maf housing? Or the intake where the stock housing bolts to it?

The intergraded MAF housing.
JLT Cold Air Intake Kit (2003-04 SVT Cobra)

I plan to install the Big MAF 3000, but it is not installed yet. I installed the stock MAF in hopes to get her running and have my tuner (pro dyno) install the big MAF when he tunes her.

 

[dazwelding]

I spoke with Dan at Pro-Dyno and I have an appointment for a tune set up next month. If I don’t get this issue figured out by then, they will fix it. However, in the meantime, keep the comments coming, I would love to hear her run again!!!

 

[03cobra#2]

The intergraded MAF housing.
JLT Cold Air Intake Kit (2003-04 SVT Cobra)

I plan to install the Big MAF 3000, but it is not installed yet. I installed the stock MAF in hopes to get her running and have my tuner (pro dyno) install the big MAF when he tunes her.

I believe that is the issue. That housing is much larger in diameter from the stock maf housing. This calls for a drastic change in your maf function. Easily corrected with a custom tune. I bet if you put the stock intake / maf housing back in it will start.

 

[dazwelding]

I believe that is the issue. That housing is much larger in diameter from the stock maf housing. This calls for a drastic change in your maf function. Easily corrected with a custom tune. I bet if you put the stock intake / maf housing back in it will start.

Does the MAF affect the fuel PSI? I am only getting 10 psi with the key on and while cranking

 

[03cobra#2]

Does the MAF affect the fuel PSI? I am only getting 10 psi with the key on and while cranking

I'm not sure exactly what the returnless system calls for as far as fuel pressure during cranking. I do know with that larger housing and no retune the car won't most likely run. The ecu is extremely sensitive to even small changes in maf / maf housing let a lone a big one like the jlt high boost Cai.

FYI I have the same intake and my car didn't start until a couple of tune revisions.

 

[01yellercobra]

The intake doesn't affect the fuel pressure. Until the pressure issue fixed the MAF curve won't matter.

Cranking the engine won't make a difference. You should have pressure as soon as you turn the key for priming. This is going to be a back to basics troubleshooting. Check all your connections to make sure they're good and tight. I didn't go with the returnless set up, but IIRC that set up still requires new power wires for the pumps right? If everything is good and you have power where you're supposed to have power then either the pumps aren't hooked up in the tank, there's a leak, or you got bad pumps.

What style hat is this? Is it the newer one with the pumps directly connected to the hat or the older style with the short piece of hose between the pump and hat?

 

[03cobra#2]

The intake doesn't affect the fuel pressure. Until the pressure issue fixed the MAF curve won't matter.

Cranking the engine won't make a difference. You should have pressure as soon as you turn the key for priming. This is going to be a back to basics troubleshooting. Check all your connections to make sure they're good and tight. I didn't go with the returnless set up, but IIRC that set up still requires new power wires for the pumps right? If everything is good and you have power where you're supposed to have power then either the pumps aren't hooked up in the tank, there's a leak, or you got bad pumps.

What style hat is this? Is it the newer one with the pumps directly connected to the hat or the older style with the short piece of hose between the pump and hat?

I'm pretty sure you won't see fuel pressure before cranking. I think when the pumps are wired to the fpdm you turn the key forward the pumps turn on for a split second and shut right off until the cranking process starts.

So I guess what I'm saying is by turning the key forward you won't really know what the fuel pressure is until the car is actually running.

The main reason I wired up my return system with pumps on with the key forward is so I can verify fuel pressure with the engine off.

 

[dazwelding]

We tried starting her up with the pumps connected directly to the battery, 70 psi, and no start. Cranked her over til the battery was near dead.

 

[dazwelding]

The intake doesn't affect the fuel pressure. Until the pressure issue fixed the MAF curve won't matter.

Cranking the engine won't make a difference. You should have pressure as soon as you turn the key for priming. This is going to be a back to basics troubleshooting. Check all your connections to make sure they're good and tight. I didn't go with the returnless set up, but IIRC that set up still requires new power wires for the pumps right? If everything is good and you have power where you're supposed to have power then either the pumps aren't hooked up in the tank, there's a leak, or you got bad pumps.

What style hat is this? Is it the newer one with the pumps directly connected to the hat or the older style with the short piece of hose between the pump and hat?

I am not sure how the pumps were connected to the hat. I bought the fore fuel hat in December of 2019, and installed it in January of 2020. I do have the black 306 wire upgrade, which wires the FPDM directly to the battery with a heavy gauge wire through a relay. I did run the pumps from the battery with the fuel filter cracked lose and it did spray fuel all over the floor, so it seems as though the pumps are working ok?? I also get 70 psi when I direct connect the pumps to the battery. Here is a pic from when we installed the pumps, before we wired them of course

 

[03cobra#2]

We tried starting her up with the pumps connected directly to the battery, 70 psi, and no start. Cranked her over til the battery was near dead.

So in essence you have verified you have fuel pressure during cranking. That's why I'm thinking maf curve needs adjusted because of the larger diameter tube.

Put the stock intake tube and maf housing and report back.

 

[dazwelding]

So in essence you have verified you have fuel pressure during cranking. That's why I'm thinking maf curve needs adjusted because of the larger diameter tube.

Put the stock intake tube and maf housing and report back.

I just cranked her over with the old JLT intake with the AL housing for the MAF. I can’t say that it’s the stock MAF tube, but it’s the one that was in it when I bought it and when it ran in 2014. No change.

 

[03cobra#2]

I just cranked her over with the old JLT intake with the AL housing for the MAF. I can’t say that it’s the stock MAF tube, but it’s the one that was in it when I bought it and when it ran in 2014. No change.

I'm not sure what the AL housing is but that's good that you checked it. I would just go through and double check all your fuses and grounds. One time I missed a ground connection and it would crank but no start. Maybe pull a cop and make sure your getting spark.

 

[01yellercobra]

I'm pretty sure you won't see fuel pressure before cranking. I think when the pumps are wired to the fpdm you turn the key forward the pumps turn on for a split second and shut right off until the cranking process starts.

So I guess what I'm saying is by turning the key forward you won't really know what the fuel pressure is until the car is actually running.

The main reason I wired up my return system with pumps on with the key forward is so I can verify fuel pressure with the engine off.

That first prime will give full pressure. It does that to make it easier to start. It's actually a 2 or 3 second prime. Plenty of time to build the pressure.

OP, have you tried firing it up with the Maf unplugged?

 

[dazwelding]

Car started tonight. The OEM gauge cluster needs to be plugged in for the car to start and run. That was it. I made a custom gauge cluster with speedhut gauges and did not have the oem cluster in. Of course there are more issues now, but I will start a new thread for those......