Discussion in 'Engine Performance + Maintenance' started by Fast 95, Mar 24, 2010.
How much fuel pressure should i have for a 96 5.7 vortec?
i belive i read somthing that said 60-65 psi but i could be wrong ill take a look. i think i saw that on GMFS. if i find it ill post a link or the info
That would be great, i dont want to spend $100 if i dont have to.
yes that was correct as far as everything i have read
copy and paste from another site
Your reading was done at idle. GM lists no fuel specs with the engine running. Below is the GM test procedure and spec:
Ignition "OFF" for 10 Seconds.
With ignition "ON," engine "OFF" and fuel pump running, pressure should be 415-455 kPa (60-66 psi).
I'm only getting 57 psi with the key on engine off, and it drops to 50 psi while running.
You should be ok with that, no matter what your pressure do that engine will be starved for fuel until you switch to a real injection system.
i also dont see that being your miss fire problem, unless one injector is pluged or somthing but you said you replace/ cleaned them i belive already so i dont see that being a cause.
57 is not enough to overcome the poppet nozzles on the Vortec. That is definitely your problem.
Its 57 with the motor not running, once started its 50 psi, and i do have the upgraded spider injectors as well.
OK, then that's probably not it. The poppets are very sensitive to low pressure.
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