351 with 2000 explorer efi will run for 1 second

[rjrobin2002]

Did a 1995 f150 351w with 351 ford lightning lower, and explorer upper, explorer trans, explorer returnless rail.

Efiguy did the harness and was aware it was going on a 351.

It will start and runs about 1 second and dies. I have about 45psi fuel pressure that builds fast with the pumps 1 second prime when I turn the key on, and the pressure stays about 45 while it starts, runs, and dies. Never changes.

I verified my efiguy harness wire for "Start hot only" is there.

I verified my harness wire needing " hot when key on and start twice"

No codes with my scanner.

What would yall do next?

 

[Broncobowsher]

Leave the MAF unplugged and try.
Take off the intake duct and try bottle feeding it, does it run that way?

 

[DirtDonk]

I’ve seen that happen before, but it’s been so long I can’t remember what the cure was.
Of course, probably several different iterations of that, so there probably isn’t just one cure.

Have you checked its ability to stay running by trying to manipulate the throttle at all? Maybe the IAC is not functioning or the throttle blade position is too far closed with the screw?

 

[rjrobin2002]

I’ve seen that happen before, but it’s been so long I can’t remember what the cure was.
Of course, probably several different iterations of that, so there probably isn’t just one cure.

Have you checked its ability to stay running by trying to manipulate the throttle at all? Maybe the IAC is not functioning or the throttle blade position is too far closed with the screw?

I'll try with the throttle half open when my friend comes over, and see if I can make it keep running with some starting fluid when he's there.

 

[rjrobin2002]

Leave the MAF unplugged and try.
Take off the intake duct and try bottle feeding it, does it run that way?

Will do tomorrow

 

[EPB72]

First thought is anti theft is still enabled in pcm,, pcm shuts off injectors if no or incorrect key is used, you will still have fuel pressure and spark as engine dies, still have power injectors just lose control,,

 

[surfer-b]

If that is a returnless system you need about 60 psi

 

[surfer-b]

not saying that is all the problem but its a start

 

[73azbronco]

shouldn't you have 65psi? Been awhile so, could be wrong.

 

[DirtDonk]

Good points. When I saw the 45 I was thinking it was fine. Totally ignored the fact that it was a returnless system.
Could the inertia switch have tripped and still show any psi readings?
I think not, but don’t know the system well enough for anything but assumptions at this point.

 

[rjrobin2002]

If that is a returnless system you need about 60 psi

I thought it needed 65 also, I am gonna get a second guage to verify my 45 reading.

 

[rjrobin2002]

Leave the MAF unplugged and try.
Take off the intake duct and try bottle feeding it, does it run that way?

I unplugged the MAF and it tried to run about 2 seconds instead of 1.

I did that about 6 times and then it actually didnt die and kept running for a few minutes. I turned it off and it restarted and stayed running, but not real good.

I plugged MAF back in and it will only run about 1 second still if MAF is plugged in.

Maybe I am on to something.

 

[Broncobowsher]

What did you do for installing the MAF? Stock housing but cut up? Generic tub with MAF insert? Is it the same inner diameter as the stock housing?
But really, do you have the airflow arrow pointing in the right direction (toward the engine). Installing backwards doesn't work.

 

[rjrobin2002]

What did you do for installing the MAF? Stock housing but cut up? Generic tub with MAF insert? Is it the same inner diameter as the stock housing?
But really, do you have the airflow arrow pointing in the right direction (toward the engine). Installing backwards doesn't work.

It's the stock housing and sensor from the 2000 explorer donor with some adapter tubes.

I will check the flow arrow tomorrow.

 

[rjrobin2002]

It's the stock housing and sensor from the 2000 explorer donor with some adapter tubes.

I will check the flow arrow tomorrow.

The flow is correct, I am guessing I need to replace it?

 

[rjrobin2002]

If that is a returnless system you need about 60 psi

I used this corvette filter/regulator to create a returnless feed for the 99-01 explorer rail. But I have it mounted close to the rear axle where my original fuel filter was.

I did some reading and I think that may be my fuel pressure issue. I am gonna move it about 6 feet closer to the fuel rail by the firewall and see if I have more pressure.

 

[EPB72]

You can block off the return port and run fuel pump and recheck pressure should climb to a 100 plus....if remains low then moving filter wont fix a thing,,,,

 

[Broncobowsher]

Good point. Pinch the return and make sure the pump can actually make the pressure.

I do question if 17Lb injectors can feed a 351 with a good flowing intake. I understand the 17s flow more like the older 19s with the higher pressure.

 

[ba123]

+1 on fuel. likely enough to start it and then not enough to keep it running.

You need to find a different regulator if it needs to be 65.

 

[rjrobin2002]

Good point. Pinch the return and make sure the pump can actually make the pressure.

I do question if 17Lb injectors can feed a 351 with a good flowing intake. I understand the 17s flow more like the older 19s with the higher pressure.

I am gonna replace the MAF.

It's the e2000 fuel pump I've used on 4 other efi swaps, but they were the early 90s mustang and 96-98 efi swaps with return lines.

I assumed it had plenty of power to make 60psi with a regulator.

We will see what the new MAF and moving the regulator close does....