Dropping fuel pressure Help

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Aug 31, 2007 | 07:37 PM

WHPLASH

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From: Macomb Michigan

Dropping fuel pressure Help

I have a Walbro intank, Msd boost a pump and a hotwire kit. Recently, under light throttle the car will drop from 61psi (on the gauge) to 57-58. Under light. When I get into it, it will drop below 50 psi.

I did check the volts and they are 18.3 and when the rpms rise under wot (boost) they go up to 18.9 I have not touched anything on the boost a pump. Its hidden.

Any suggestions where to look or what to do? Is the Walbro going out?

Sep 1, 2007 | 08:10 PM

WHPLASH

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Any thoughts???

Sep 2, 2007 | 01:11 AM

Tiger2o69

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From: MS

same thing is happening to me.

Sep 3, 2007 | 02:20 PM

WHPLASH

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Help....

Sep 3, 2007 | 05:10 PM

onfire

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From: Virginia

Light throttle drop of 3 pis is not a concern. Dropping under 50psi at wot is a concern. How old is the pump? Has it always done this? Could be a leak at the pump.

Sep 3, 2007 | 05:42 PM

WHPLASH

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It has 8000 miles on it. 4 yrs old. It has never done this before.

Sep 3, 2007 | 07:19 PM

onfire

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From: Virginia

Quote:

Originally Posted by WHPLASH

It has 8000 miles on it. 4 yrs old. It has never done this before.

Then I would:

1. Change the fuel filter and see what happens.

2. Check the pump and make sure the fuel line is not split at the pump...possibly change the inlet sock now since you'tr there.

3. Get a new pump if 1 and 2 don't fix it.

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Sep 4, 2007 | 09:55 PM

Detroitmuscle

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From: Shelby Twp.

Let me know what you discover, my car straight died on me this morning and I'm getting no fuel pump turning on at all. I've heard that sometimes the hose coming from the pump itself needs to have another clamp placed on it otherwise it tends to leak.