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No fuel pressure to test port on fuel rail but good pressure from pump when disconnec by Steelers8
Started on: 07-05-2021 10:53 PM
Replies: 23 (266 views)
Last post by: Patrick on 09-07-2021 04:40 PM
Steelers8
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Report this Post07-05-2021 10:53 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
I just put heads on and car ran before. Put new Coil, Distributor, Injectors, Fan Switch, and Coolant Switch. Car starts if carb cleaner sprayed in but pump disconnected before filter has 70 lbs but nothing at valve on fuel rail? Any ideas because seems to have pulse but no pressure?

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Report this Post07-06-2021 12:38 AM Click Here to See the Profile for Mike in SydneySend a Private Message to Mike in SydneyEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm guessing clogged fuel filter, pinched fuel line between output from pump and fuel rail, or faulty fuel pressure regulator. If you disconnect the fuel line from the fuel rail do you get fuel when you turn on the ignition? CAUTION: Do not crank car. Do not check with warm or hot engine. Do not do alone. Have a Class B fire extinguisher close by.
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Report this Post07-06-2021 12:56 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
New fuel filter. With pump hooked up 10 lbs before and after filter. Gas to fuel rail. No pressure out the valve. Gas coming out return but pressure does not go up in pinch return. Could pressure regulator just stop working while I was putting heads on?

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Mike in Sydney
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Report this Post07-06-2021 02:01 AM Click Here to See the Profile for Mike in SydneySend a Private Message to Mike in SydneyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like you have a fuel pump issue. See this thread about half way down. https://www.fiero.nl/forum/Forum2/HTML/138476.html Yes, I know this is about a new pump but the items mentioned by Dennis are places to start looking.
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Report this Post07-06-2021 02:14 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

pump disconnected before filter has 70 lbs but nothing at valve on fuel rail?


 
quote
Originally posted by Steelers8:

With pump hooked up 10 lbs before and after filter. Gas to fuel rail. No pressure out the valve.


???

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Report this Post07-06-2021 02:27 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Guess I will have to change the regulator then. Seems odd it went out when it was fine before.

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Report this Post07-06-2021 02:40 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

???


Just powering up the pump with battery charger and when I just pressure with tester before the filter reads 10. Disconnected and put after filter 10. Before filer just pump not connected to fuel line 70.

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Will
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Report this Post07-06-2021 08:54 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

Just powering up the pump with battery charger and when I just pressure with tester before the filter reads 10. Disconnected and put after filter 10. Before filer just pump not connected to fuel line 70.



So you have 70 psi upstream of the fuel filter and 10 psi at every point downstream of the fuel filter? Sounds like your fuel filter was bad out of the box.

However, you also said the 10 psi at the rail does not increase when you pinch off the regulator return?
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Report this Post07-06-2021 08:59 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
No I got 70 before fuel filter without being connected to the fuel filter but if connected through the system 10 before and after the filter but no pressure at the valve at the fuel rail. A lot of gas on the return line but doesn’t increase if I pinch off the return.

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Report this Post07-06-2021 09:02 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post

Steelers8

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quote
Originally posted by Will:


So you have 70 psi upstream of the fuel filter and 10 psi at every point downstream of the fuel filter? Sounds like your fuel filter was bad out of the box.

However, you also said the 10 psi at the rail does not increase when you pinch off the regulator return?


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Report this Post07-06-2021 09:04 AM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post

Steelers8

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70 before fuel filter not connected to anything but pump. If connected to fuel filter 10 before and after and no pressure at rail.
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Report this Post07-07-2021 06:27 PM Click Here to See the Profile for Mike in SydneySend a Private Message to Mike in SydneyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

70 before fuel filter not connected to anything but pump. If connected to fuel filter 10 before and after and no pressure at rail.


I've been scratching my head on this. How are you measuring pressure between the pump and the fuel filter? Is there a Schrader valve in the line, there? Can you upload an image?
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Report this Post07-07-2021 08:10 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
I have pressure now. It will only start and go up to 1100 rpms and dies. Sounds like maybe a vacuum leak. Any ideas were to start?

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Report this Post07-07-2021 08:28 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

70 before fuel filter not connected to anything but pump. If connected to fuel filter 10 before and after and no pressure at rail.


So just to clear things up I'm assuming you mean 70 psi. I'm assuming you're dead-heading the fuel pump with a reliable gauge before any fuel gets to the 1st component being the fuel filter. If this is so, then you've proved that the fuel pump is capable of producing adequate static-pressure but that does not always equal adequate dynamic-pressure or flow / volume.

If I was in this situation I would use a pressure gauge of the proper range, an appropriate ball valve to regulate the pressure and a measuring container to collect the results and compare this to the manufacturers specifications of the pump. Example, 1.5 gallons per minute @ 55 psi.
Once the pump has proven itself then I would add in the fuel filter and retest. If all proves well then I would allow fuel to flow to the regulator and so on.

I would also recheck the schrader valve on the fuel rail. The core could be bent off center and its not being depressed. Replacements are available for fuel use.
---end of "If I was in this situation". Just like on TV, results may vary...

Spoon


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Report this Post07-07-2021 09:03 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

I have pressure now.


Tell us what you did.


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Report this Post07-07-2021 09:13 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Well took fuel pump assembly out and put in a bucket of gas so now good fuel pressure at fuel rail. It starts but only goes to 1100 rpm and dies. Sounds like maybe a vacuum leak! Any idea where to start looking? Everything is hooked up. New intake gaskets. Could it be there or idle sensor?

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Report this Post09-02-2021 08:58 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
Well put new intake gaskets in and no more vacuum leak but it is timed now but will not idle. Starts but as soon as I take my foot off the brake it dies. Can’t even put in reverse to back out of the garage. Any ideas please!

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Report this Post09-02-2021 09:05 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

What is the fuel pressure at the schrader valve on the fuel rail?
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Report this Post09-02-2021 09:18 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
43 lbs

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Report this Post09-07-2021 08:35 AM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

Well took fuel pump assembly out and put in a bucket of gas so now good fuel pressure at fuel rail. It starts but only goes to 1100 rpm and dies. Sounds like maybe a vacuum leak! Any idea where to start looking? Everything is hooked up. New intake gaskets. Could it be there or idle sensor?



I would advise against using live wires and testing the pump in a bucket of gasoline. Quite frankly I cannot even see how you can measure the pressure this way. What was the procedure? If you now have 43 psi at the rail then fuel pressure is up to spec. This whole episode sounds extremely strange.

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Report this Post09-07-2021 02:00 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
So what is next? Check all injectors with noid light?

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Report this Post09-07-2021 03:54 PM Click Here to See the Profile for reinhartClick Here to Email reinhartSend a Private Message to reinhartEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Dennis LaGrua:


I would advise against using live wires and testing the pump in a bucket of gasoline. Quite frankly I cannot even see how you can measure the pressure this way. What was the procedure? If you now have 43 psi at the rail then fuel pressure is up to spec. This whole episode sounds extremely strange.



Yes I have no idea what the OP is doing. Each post/test is more confusing than the previous one.
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Report this Post09-07-2021 04:21 PM Click Here to See the Profile for Steelers8Click Here to Email Steelers8Send a Private Message to Steelers8Edit/Delete MessageReply w/QuoteDirect Link to This Post
I agree. Someone made me go back to this post. Guess I will have to figure it out.

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Patrick
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Report this Post09-07-2021 04:40 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steelers8:

Someone made me go back to this post.




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