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Old 08-23-2017   #1
Regimof
 
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Default New fuel pump. Takes much longer to start

So I recently put in a new fuel pump in. Seemed pretty straight forward. Now it turns over for quite a bit longer before it starts.

Thoughts?
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Old 08-24-2017   #2
BigJohn
 
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Default Re: New fuel pump. Takes much longer to start

Some of the new fuel pumps are coming out with defective hoses; from small leaks to in time splitting the full length of the hose.
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Old 08-24-2017   #3
Paul Workman
 
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Default Re: New fuel pump. Takes much longer to start

One thing at a time: I'd suggest you'd first want to know the fuel pressure readings at the rail with the key ON, before turning the starter (to see if adequate fuel pressure is present), before hypothesizing further or raining parts on it.
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Old 08-24-2017   #4
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Default Re: New fuel pump. Takes much longer to start

Quote:
Originally Posted by Paul Workman View Post
One thing at a time: I'd suggest you'd first want to know the fuel pressure readings at the rail with the key ON, before turning the starter (to see if adequate fuel pressure is present), before hypothesizing further or raining parts on it.


Never done that before. I assume there's a video somewhere on how to do it?
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Old 08-24-2017   #5
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Default Re: New fuel pump. Takes much longer to start

When I start my car I turn key to on position, let pumps pressurize system then turn to start, hold key longer than a regular car to avoid backfire, after replacing both my pumps my car starts faster now than it did with old pumps
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Old 08-25-2017   #6
Paul Workman
 
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Default Re: New fuel pump. Takes much longer to start

Quote:
Originally Posted by Regimof View Post
Never done that before. I assume there's a video somewhere on how to do it?
No video needed, really. Just remove the safety cap from the Schrader valve at the front of the (passenger-side) rail, and connect a fuel pressure gauge to the valve. (I got mine gauge [AND an extension too!] from Harbor Freight).

Turning the ignition switch to ON and pausing (as PhillipsLT5 described), you should see the pressure in the mid 40s (e.g., ~45± 2#). (And, BTW, after turning the switch OFF, the pressure should hold to a pound or two for 10-15 minutes or so. If if falls off faster, either a check-valve in one of the fuel pumps is bad, or there is one or more leaking injectors; neither is a good thing - especially if it is leaking injectors. But, that is getting further off topic!)
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SW headers, X-pipe, MF muffs

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Old 08-25-2017   #7
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Default Re: New fuel pump. Takes much longer to start

Quote:
Originally Posted by Regimof View Post
So I recently put in a new fuel pump in. Seemed pretty straight forward. Now it turns over for quite a bit longer before it starts.

Thoughts?
How much longer ?
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Old 08-25-2017   #8
LGAFF
 
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Default Re: New fuel pump. Takes much longer to start

Longer crank can sometimes mean the check valve is not working on a pump
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Old 08-26-2017   #9
Hog
 
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Default Re: New fuel pump. Takes much longer to start

Cycle the key once to cycle the pump. That will pre pressurize the system before you engage the starter to crank the engine.

Since the new symptom occurred concurrently with a pump change, something in the pump or near the pump is letting pressure back into the tank.

I agree with Lee on this one.

The start of this video explains the potential issue.
https://www.youtube.com/watch?v=5YLRtA_QHa8
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