LT1/LT4 Tech 1993-1997

Fuel Pressuse

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Old 01-31-2017, 11:34 AM
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Question Fuel Pressuse

96 Z-28 i have a fuel pressure gauge hooked up when i turn the key on pressure goes to 46 pounds as soon as the solenoid behind the kick panel on the drivers side hits the 2 or 3 second time out the pressure drops to zero is this normal i have not tried to crank it over yet to see what that reads working on some battery issues
 
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Old 01-31-2017, 12:06 PM
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No, pressure should drop a little, but hold for a while. Either bad fuel pressure regulator, or check valve in fuel pump isn't holding. Pull vacuum hose off the f.p.r. and check if fuel is in there. If there is, the regulator is bad.
 
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Old 01-31-2017, 05:26 PM
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Default Fuel pressure

Originally Posted by Camaro 69
No, pressure should drop a little, but hold for a while. Either bad fuel pressure regulator, or check valve in fuel pump isn't holding. Pull vacuum hose off the f.p.r. and check if fuel is in there. If there is, the regulator is bad.
Ok I will check the FPR I just replaced the FPR so I know it is brand new but yes it can be bad I know that I also replaced all the o rings and filters in the injectors but I will continue to check these things
Thank you for the info
 
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Old 02-12-2017, 10:34 AM
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Hello again quick question when are the injectors supposed to spray . I turn the switch on but not try to start some of the injectors spray and some dont and the fuel rail will not hold pressure they spray only in the start position correct and what should i buy if i replace them all it is a factory stock 350 LT1 96 Z 28
 
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Old 02-12-2017, 02:25 PM
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did this start after you replaced the fpr?
 
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Old 02-12-2017, 06:59 PM
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No it turns over but will not start
 
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Old 04-02-2017, 10:24 AM
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Hello again it has been a while since I had time to do some more troubleshooting on this car .But what I found was it was not holding fuel pressure I found the problem to be the injectors so I replaced them all also I had 8 ouarts of oil and mostley gas in the oil pan .I drained that out and let it dry out a few days replaced with new oil and filter turned on the switch the fuel relay engaged timed out in a few seconds fuel pressure went to 45 psi started the motor it fired right away i let it run for 10 to 15 minutes to build heat I turned it off to check the fluids .I will be changing the oil again Tuesday should I be concerned with all that gas in the oil pan as the engine did run for a little while with all that in the pan but not for more then 10 minutes or so
 
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Old 04-02-2017, 03:32 PM
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whats left will evaperate once the engine gets to operating temp and go into the the air intake system through the pcv valve.
 
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Old 04-02-2017, 05:13 PM
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Hello ok thanks for that info that helps me also after all this when I start the car and let it get up to temp and cut it off it is kinda hard to get it to start back up till it cools off some any ideas or what I should check next
 
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Old 04-02-2017, 11:02 PM
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fuel pressure would be one, tired fuel pump can perform poorly once warmed up. ignition module is another, it can fail once warmed up. is it turning over slowly when it wont start or does it turn over the same when trying to start all the time. unhappy starter can lose power once warmed and not turn the engine over fast enough to start, draws to much voltage from the battery
 


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