Fuel pressure test 5.7 vortec

[96z71sas]

Does anybody remember how to run fuel pressure test I can’t find a thread I think it’s 55psi key on and should hold steady and 60 while running any help would be great thanks

 

[east302]

Spec is 60-66 psi key on, engine off. Here are the pages from the manual (1998, 350) for testing…

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[east302]

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[96z71sas]

Spec is 60-66 psi key on, engine off. Here are the pages from the manual (1998, 350) for testing…

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Thanks very help

 

[L31MaxExpress]

MFI spider runs at lower pressure if yours has been converted.

 

[GXpress]

MFI spider runs at lower pressure if yours has been converted.

Hi old thread but wanted to ask you. I did the MFI conversion a while ago. I have an issue where my van wont start, i definitely have spark fuel and air. Re did the distributor timing with cyl #1 at TDC timing mark on damper lined with timing notch on timing cover, lined the dimple on the distributor with the line on distributor shaft. Rotor on distributor pointed towards where the flat edge of the distributor curves off. When distributor fell into place, it pointed towards cylinder #1.

I tested fuel pressure and its around 58 PSI key open engine off .when fuel pump stops priming, it immediately drops a few psi to 552-54PSI and it does hold pressure.

Due to a different issue the van has the following parts brand new

ICM
Distributor/cap/rotor
Coil
Spark plug wires
Timing chain
Mass airflow
Reman.. ECM
Crank sensor
New spider MFI injectors(replaced the ones I installed in 2011)
New lower/upper intake gasket
New upper plenum
New exhaust: y-pipe with cat all the way back
Fresh 02 sensors acdelco

About the only thing i need to do is the spark plugs (4years old)

…And “maybe fuel pump”

Engine still wont start.. stumped.

96 express 5.0

Thanks in advance

 

[Nad_Yvalhosert]

@GXpress

Will it start on starting fluid?

Have you checked for spark?
Vortec engines require a scanner to set the crank angle sensor. The ole trick of setting the distributor to #1 wont cut it.

Was the "Reman.. ECM" flashed at the time of install?

 

[GXpress]

It definitely has spark its among the list of parts I posted. Thing is that the engine has that sound like its about to start but just doesnt. It briefly started once and stumbled to off. I set the distributor as per the manual but ive read the engine is supposed to start and then you set timing if the code “correlation with CPS” is incorrect?

Yes , the ecm was flashed with the latest updates. I just literally got off the phone with flashmasters, thats the company who sold me the ecm. Van was running superb before it shut off.

 

[Schurkey]

You can turn the distributor every day and twice on weekends, without affecting the ignition timing. Turning the distributor on a Vortec does not change the timing, it changes the alignment between the rotor and cap terminal; and it changes the synchronization of the crank sensor signal and the cam sensor signal.

If the distributor is far enough out of alignment, the spark might jump to the wrong terminal.

I have an issue where my van wont start, i definitely have spark fuel and air. Re did the distributor timing with cyl #1 at TDC timing mark on damper

WHICH "TDC"? There's two of them. TDC Exhaust, and TDC Compression.

Due to a different issue the van has the following parts brand new

Timing chain

Has the engine run since the timing chain was installed?

Wild Guess: You installed the timing chain "dot-to-dot", crank gear at 12:00, cam gear at 6:00, and then dropped the distributor in pointing to #1. Engine won't run. Distributor is 180-degrees off. Turn damper to "TDC", pull distributor. Turn crank one entire revolution, back to TDC. Reinstall distributor per service manual alignment.

Don't forget to connect a scan tool to set the "cam offset" or whatever your tool calls it, once you fire up the engine.

 

[GXpress]

You can turn the distributor every day and twice on weekends, without affecting the ignition timing. Turning the distributor on a Vortec does not change the timing, it changes the alignment between the rotor and cap terminal; and it changes the synchronization of the crank sensor signal and the cam sensor signal.

If the distributor is far enough out of alignment, the spark might jump to the wrong terminal.


WHICH "TDC"? There's two of them. TDC Exhaust, and TDC Compression.


Has the engine run since the timing chain was installed?

Wild Guess: You installed the timing chain "dot-to-dot", crank gear at 12:00, cam gear at 6:00, and then dropped the distributor in pointing to #1. Engine won't run. Distributor is 180-degrees off. Turn damper to "TDC", pull distributor. Turn crank one entire revolution, back to TDC. Reinstall distributor per service manual alignment.

Don't forget to connect a scan tool to set the "cam offset" or whatever your tool calls it, once you fire up the engine.

I just finished working on the engine and nothing no start. I took the distributor out again, had someone bump start the engine until i felt compression on my finger at cyl #1 then by hand moved the crank to align with notch on timing cover. The distributor has a dimple which i aligned with the line on the distributor shaft i inserted the distributor with rotor pointing towards cyl #1 as gear engaged it finished testing with rotor pointing to where the edge of the distributor has a bend.

Did i do it wrong? By the way fuel pressure while cranking falls to 42 psi and then as i let go of the key it shoots up to 60 and stays there.

Engine has not run after timing chain replacement. Iam in this hole
Because the van shut off on me without any warning. Being i had changed out the distributor for a different reason three months ago i never got to time the engine with the scan tool but it ran excellent except for slight pinging when going into overdrive.

Being the engine shut off on me i thought maybe the slight detonation killed the timing chain, stretched it out, because as far as I know the chain is original and the van has 220k.

Here is the biggest clue in everything that i think is crucial. When the van shut off and I went to restart it, it sounded like the ignition timing was off because it did the typical chevy engine start where it cranks then slows up then spins up…