Cold Start up

PJMCCARL

MEMBER
1996 CHEVROLET EXPRESS
V8
2WD
AUTOMATIC
110,000 MILES

Having cold start issues that has increased overtime, suspected low fuel pressure, start up pressure seems to be around 55lbs, will hold pressure, seems to be normal leak down once it's started. Tune up has been done, and no codes have been set off. I have read conflicting thoughts on correct start up fuel pressure. Like to get your opinion on.

1. Correct start up fuel pressure?
2. Any thoughts on possible problems?

6 Replies

WRENCHTECH

MECHANIC
20,758 POSTS

Coolant Temperature Sensors: Some temperature sensors in the engine control system (like the coolant temperature sensor or intake air temperature sensor) provide data to the engine control module for proper cold start enrichment.

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Friday, August 20th, 2010 AT 12:53 PM

PJMCCARL

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4 POSTS

I want to install a new fuel pump?

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Friday, August 20th, 2010 AT 2:20 PM

WRENCHTECH

MECHANIC
20,758 POSTS

Please use this guide

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

FUEL PRESSURE SPECIFICATIONS
Ignition On, Engine Off
Central FI 415 - 455 kPa (60 - 66 psi)
SFI 385 - 430 kPa (56 - 62 psi)

I would say your on the right track with fuel pressure. These things won't even run under 55PSI

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Friday, August 20th, 2010 AT 2:30 PM

PJMCCARL

MEMBER
4 POSTS

I have a fuel gauge hook up all the time and have left overnight and start up pressure is 35, once started after 4 or 5 times of starter turnover and starts, it stays at 45. Is there a minimum pressure for this motor?

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Friday, August 20th, 2010 AT 2:55 PM

WRENCHTECH

MECHANIC
20,758 POSTS

Yes, the low end of the spec is the minimum. I know these systems have no tolerance for low pressure. Like I said, many of them won't even run under 55PSI.