Etest and base fuel pressure.

[Intmdtr]

so 96 GT failed etest by .05 on the Idle CO% see pic. (Pic won't load). All other test past except for CO% at idle....limit 1, reading 1.05 for a fail

Anyway, computer is telling me idle fuel pressure is only around 20psi. Aftermarket fuel rail gauge shows 22 psi at idle 800 rpm. Stock pump, stock injectors, stock fuel pressure regulator on a 91 octane dyno tune.....


Where do I go from here, anyone know what idle fuel pressure should be? And causes of low fuel pressure? New fuel filter last fall.

[RedSN]

Isn't '96 simply an OBDII test? What were you doing with the tail pipe sniff?



edit: never mind .....cars and vans (model years 1988–1997) Tailpipe test

Advance your timing a tad, and retest.
They don't test for NOx anymore.

[Intmdtr]

My tune is locked so I can't advance the timing. Thinking I should bite the bullet on the Wahlbro 255lph in tank pump from steeda...I might have it by tomorrow.

[Intmdtr]

I have 39psi @idle with vac line removed from fuel pressure regulator and 39 psi at higher idle...hook vac line back up and the pressure drops back below 25psi @idle, but climbs to 39psi with an increase in rpm.

Pump problem?

[ZR]

Did it pop a code?

[Intmdtr]

Only code showing on scanner is P1443 evaporative emissions system control valve (low/no flow)

[ZR]

Pump at Steeda you posted, that'll certainly do the job.

[Ghost Rider]

so it failed because of the pump...or this is two separate issues?

[ZR]

Did you run it through with or without the tune in place?

[Intmdtr]

I don't have the stock tune anymore, so it was on the 91 street tune. I am thinking, and the tech that Etested it said because the idle fuel psi is low that the problem lies there.