Check the circle connectors at the front of the valve cover, make sure those are in correctly those tend to not be plugged in, also check the two connectors on the driver side shock tower AND make sure the pcm connect on firewall is clipped in all the way as well. Where the injector harness’s installed correctly? Ie..pushed in all the way?


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Check the circle connectors at the front of the valve cover, make sure those are in correctly those tend to not be plugged in, also check the two connectors on the driver side shock tower AND make sure the pcm connect on firewall is clipped in all the way as well. Where the injector harness’s

installed correctly? Ie..pushed in all the way?


All connections are connected. Computer sees all sensors on the motor. It acts like the injectors don’t want to start injection.


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So you have no gear indicator on the dash?


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Hear indicator is there. Is in park. Linkage is correctZ also checked the neutral safety switch. The truck does crank over, the injectors just won’t turn on during crank.

 

Did you check that inertia switch?

A leak, or weak pump. Or air.
Even those you might thing you have all the air out you may not. Crack the rear 17mm and also purge the shrader at the front.

How are your orings at the fuel filters as well?


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We’ve purged air for 6 days. No air coming out. All seals are new. We’re gonna try and put some batteries on it.

 

If you don’t hit exactly 5000psi they will not even try to open. So suspect a weak pump which probably caused the injectors to fail in the first place.


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We have 250mL return coming back from the injectors. Pump is what we suspect. Will keep an update.

 

We still have no luck. And I misspoke, 5000 psi was our commanded fuel pressure. Actual is zero. High pressure fuel pump has been replaced. Bled fuel, no crank. Bled lines at 17mm banjo, air then steady stream. Bled lines to last injector on each bank, air then steady stream. We still have no rail pressure. There is stream but not enough restriction. Everything has been torqued to spec. Cab has been up and down twice now. Looking towards the PCV which is commanding but not responding.

 

You have 0 frp when cranking? That’s a little odd you should see at least something.
What do you mean by look towards PCV? The pcv system only relieves crank case pressure into the intake.
Was the HPFP harness changed as well?
I know this is going to sound crazy. But you may have a bad HPFP out of the box. There has been many threads of guys going crazy when it was just a bad pump out of the box. I think one guy went through 3 until one worked
Now i’d start looking at the pcm tho.

Are there any codes at all?

Is this truck completely stock?

Also you checked the INERTIA switch on the passenger side dash?

You originally said you had 4300frp now you’re saying 0?

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Sorry also, you checked the low prressure fuel pump pressure? Should be 6-8psi


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We switched from a heavy duty diesel laptop to the Snap On Zeus because one was giving mislabeled data. Our cranking frp is 0. We pinned out the PCM today to the sensors on rail. Fuel rail pressure sensor, Pressure control valve, and injectors. Harness to sensors and harness to injectors tested fine. They are receiving signal but not kicking on the injectors which is due to the PCM not seeing any fuel pressure. When we crack lines while cranking I could piss harder than the flow coming out. Low pressure side is 3psi tested with fuel pressure kit and I saw where spec was 3-8 but 6-8 sounds better to me. I don’t put it past it that the new HPFP could be bad. Sounds like the cab is going up. Third time is the charm?