home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 05-21-2021, 08:12 PM   #1
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default Fuel flowing back into tank after shutdown

Don’t know if it’s the return line or what but, when it shuts down I can hear fuel flowing back into the tank.

Pressure regulator, pump or check valve?
__________________
Quote:
She’s built like a steakhouse but, she handles like a bistro.
BeaverMeat is offline   Reply With Quote
Old 05-21-2021, 08:20 PM   #2
apachechef
Burnt Sierra Madre
 
Join Date: Jan 2009
Location: Fort Joe Smith, Klendathu
Default

consider normal operation
__________________
Quote:
Originally Posted by lummert View Post
Dammit, Lummert.
Quote:
Originally Posted by Jesse8931 View Post
Well keep us updated on how your dumbass plan goes.
apachechef is offline   Reply With Quote
Old 05-21-2021, 08:25 PM   #3
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

Quote:
Originally Posted by apachechef View Post
consider normal operation
Never did it before...
BeaverMeat is offline   Reply With Quote
Old 05-21-2021, 09:05 PM   #4
cosbySweater
Board Member
 
cosbySweater's Avatar
 
Join Date: Jul 2009
Location: Monterey/Falun
Default

What pumps are you using?
__________________
1974 AMC Gremlin, lq4, 7875 billet, ss2 cam, 80e, 3600 stall converter, Holley Terminator x
1984 Volvo 245 Om606td, 722.6, Lifted
1995 Porsche 993
2013 VW Passat TDI
Quote:
Originally Posted by bricktop420 View Post
Thank you very much everybody... i now feel sufficiently retarded and will go cry in the corner...
cosbySweater is online now   Reply With Quote
Old 05-21-2021, 09:09 PM   #5
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

Quote:
Originally Posted by cosbySweater View Post
What pumps are you using?
OE fuel (external) pump. Oh... the engine is a 302EFI with a vacuum operated fuel pressure regulator.
BeaverMeat is offline   Reply With Quote
Old 05-21-2021, 09:27 PM   #6
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Gee, that is an interesting piece of information.
__________________


1982 Volvo 245 with a Ford 302 V8

Ford V8 Conversion Manual -
http://forums.turbobricks.com/showthread.php?t=250257

Bertone Restoration - http://forums.turbobricks.com/showthread.php?t=256460
TestPoint is offline   Reply With Quote
Old 05-21-2021, 09:45 PM   #7
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

Quote:
Originally Posted by TestPoint View Post
Gee, that is an interesting piece of information.
What?

It’s just the regular ‘81 vintage type external fuel pump. Or the was it the pressure regulator? Still learning the ins-and-outs of this thing.

Perhaps it’s normal and I never noticed it before? The return line emptying out? I thought the whole system should be pressured.

Last edited by BeaverMeat; 05-21-2021 at 09:50 PM..
BeaverMeat is offline   Reply With Quote
Old 05-21-2021, 10:11 PM   #8
2 old for this
Board Member
 
Join Date: Mar 2018
Location: Amarillo and the Sanger de Cristo mountians
Default

Oe pumps have a check valve which keeps the system pressurized
2 old for this is offline   Reply With Quote
Old 05-21-2021, 10:58 PM   #9
lookforjoe
Making Volvo Parts Fit
 
lookforjoe's Avatar
 
Join Date: May 2008
Location: Rockland County, NY
Default

Quote:
Originally Posted by BeaverMeat View Post
What?

It’s just the regular ‘81 vintage type external fuel pump. Or the was it the pressure regulator? Still learning the ins-and-outs of this thing.

Perhaps it’s normal and I never noticed it before? The return line emptying out? I thought the whole system should be pressured.
81 K-jet cars had a pulse damper mounted on the bracket underneath next to the main (external) pump. The (control) pressure regulator was mounted under the intake
__________________

My XR July2013 - 446AWHP @ 8K rpm C30 AWD conversion Feedback Thread
lookforjoe is offline   Reply With Quote
Old 05-21-2021, 11:18 PM   #10
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

Well. This is a 5.0L swapped car where the Diesel fuel components were swapped for gas ones. I’ll check if there is even a check valve.

Other cause could be a faulty regulator/vacuum leak.

I’m starting think this may actually be the problem with my misfire issues

Last edited by BeaverMeat; 05-22-2021 at 12:01 AM..
BeaverMeat is offline   Reply With Quote
Old 05-22-2021, 05:11 PM   #11
dl242gt
My car is fun hp club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

It's normal to have fuel emptying to the tank after shutdown. The check valve slows down the decay of fuel pressure for easier hot starting. But it's normal for the system to empty out after shutdown. it just should take awhile like about 20 minutes to a half hour. It's called the rest pressure in a kjet system.
dl242gt is offline   Reply With Quote
Old 05-22-2021, 05:50 PM   #12
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

Quote:
Originally Posted by dl242gt View Post
It's normal to have fuel emptying to the tank after shutdown. The check valve slows down the decay of fuel pressure for easier hot starting. But it's normal for the system to empty out after shutdown. it just should take awhile like about 20 minutes to a half hour. It's called the rest pressure in a kjet system.
Yup. It flows back immediately after shutdown and there is zero pressure in the line.

Last edited by BeaverMeat; 05-23-2021 at 12:01 AM..
BeaverMeat is offline   Reply With Quote
Old 05-23-2021, 07:31 PM   #13
gsellstr
Vintage anti-ricer
 
gsellstr's Avatar
 
Join Date: Oct 2004
Location: Somewhere in a northern California smog bank
Default

Think about this for a minute guys.

The check valve is on the pressure side, the outlet of the pump.
The fuel pressure regulator determines how much fuel is returned to the tank, after fuel has run thru the rail.
There's no restriction on the return line to the tank once fuel leaves the regulator, never was, shouldn't be in this setup.
There's no way to have pressure in the return line without a restriction.

If the PRESSURE side is losing pressure, that's a different story. A quick check of fuel pressure with the engine running, then shut it off, see what happens will tell you if there's an issue on the pressure side.
__________________
RIP
Doug Williams "Mr. Doug" 4/15/2009
Pete Fluitman "fivehundred" 7/14/2013
Mick Starkey "TrickMick" 1/10/14
Mark Baldwin "blue850t5" 7/19/18
Nick Fengler "fengler" 8/6/18
Thomas Fritz "stealthfti" 10/11/18


74 144 B20
http://forums.turbobricks.com/showthread.php?t=224983

90 745Ti
http://forums.turbobricks.com/showthread.php?t=334698

If you need Superpro bushings PM me for price and availability!
gsellstr is offline   Reply With Quote
Old 05-25-2021, 12:59 PM   #14
dl242gt
My car is fun hp club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

Just to clarify what I wrote. The fuel pressure decay after shut down is slowed down by the check valve in the fuel pump. This is happening in the area between the fuel pump and the fuel pressure regulator. However, as Gary wrote, the fuel system after the regulator has now restriction so it will empty out quickly after shutdown.
dl242gt is offline   Reply With Quote
Old 05-27-2021, 01:12 PM   #15
BeaverMeat
Board Member
 
BeaverMeat's Avatar
 
Join Date: Aug 2020
Location: Vancouver Island
Default

I did the complete Fox 5.0 pulsing idle/3000rpm+ check list and ran the codes. Got a code 67 and 95.

67 is the neutral safety switch (which isn’t connected). Code 95 which is “fuel pump secondary circuit” fuel pump error. Meaning the relay didn’t kick-in the pump when the ECU told it to do so.

The car uses the Ford pump relay to run the Volvo duel pumps. So... I don’t know if it’s the swap that throws the code or of the ECU is doing it’s job.

The car primes as it should... I can hear the line pump. Perhaps my tank pump isn’t working and is throwing the code.

Last edited by BeaverMeat; 05-27-2021 at 01:20 PM..
BeaverMeat is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 07:57 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.