Engine power goes down time to time - fuel pressure issue - Taurus Car Club of America : Ford Taurus Forum
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 34 (permalink) Old 07-07-2013, 02:35 AM Thread Starter
Junior Member
 
Join Date: May 2011
Location: Dammam, Saudi Arabia
Chapter: Northeast
Posts: 94
Rep Power: 17
 
Trader Score: 0 reviews
Engine power goes down time to time - fuel pressure issue

One month before when i took my car for a long journey (1200 km) one time i noticed the car didn't accelerate and lost its power, i stopped at a gas station and checked nothign found abnormal, when i started the car it got ok and i didn't get this issue again.

after that i sued this car daily 200 km drive, i didn't get this issue.

Again i went on a long journey, Yesterday i was returning back home the issue started. its like when go on slop up or down the car suddenly loses its power, RPM comes down though give fuel, like rpm doesn't shoot up. if on flat road it goes smooth. if i turn ignition off and start the engine on slope up/down it get its power and accelerate normal to full speed when any slope comes again it loses its power. i had to turn off ignition and start engine again every time when it did so.

I had a check car stopped it idles good, but no power if off and start again it becomes good and rpm goes normal. checked fuel rail pressure when the issue was there, pressure was low. i doubted the fuel relay and i swapped with another one, still the issue was same.

my questions
1- what are the steps i have to follow for further checks ( no engine code at present)
2- why it gets ok every time i start it
3- I noticed at beginning it ran good and the issue started when engine got hot, can it be related to any component? (due to less power heat didn't raise or come to middle)
4- the car uses return fuel system as i know, the filter have a return line, any advice to change it?
5- what about fuel pump? can this get ok only at start and goes weak every time?
mbarazeen is offline  
Sponsored Links
Advertisement
 
post #2 of 34 (permalink) Old 07-07-2013, 08:20 AM
Devoted Member
 
Join Date: Apr 2003
Location: Virginia
Chapter: Southeast
Year: 94
Model: Ford Taurus
Engine: 3.8L Essex
Posts: 2,433
Rep Power: 44
 
Trader Score: 0 reviews
You may have more than one problem. Have the engine computer scanned for trouble codes & post All code Numbers, as they can offer up good trouble shooting clues.

Good trouble shooting idea to try swapping out the fuel pump power relay, as its a common problem part.

When the fuel pressure was low, did you measure under load operating voltage to the fuel pump??? If fuel pump operating voltage is ok, but fuel pressure is still low, when the problem is present & the engine is running, try removing & reinstalling the gas cap to equalize fuel tank pressure & see if the engine power immediately returns. If so, suspect the gas cap isn't properly venting the fuel tank, so replace the gas cap with a Ford part.

Is the fuel filter due, or past due for scheduled replacement??? If so, do that & see if the fuel pressure returns to normal.

When you've had the problems, were you using a quality fuel, one that your certain that its vapor pressure is properly adjusted for the hot climate your in. I'm thinking of possible vapor lock problems, with the fuel boiling in the lines under hot weather & high speed highway operation.

Some thoughts for consideration, let us know how your trouble shoot goes.

94 Taurus GL 3.8L PEP204A
99 Ranger XLT 4dr 4.0L 5spd Auto
Payload & Tow Pkg

Details are trifles, but trifles make perfection & perfection is no trifle (Ben Franklin)
Our signature is a sign of a job completed, autograph your work with excellence.
pawpaw is offline  
post #3 of 34 (permalink) Old 07-07-2013, 08:33 AM
Play Nice or Don't Play

 
jag1959's Avatar
 
Join Date: Jun 2011
Chapter: Northeast
Year: 1998
Model: Ford Taurus SHO
Engine: 3.4L Yamaha V8
Posts: 14,786
Rep Power: 120
       
Trader Score: 0 reviews
Suspect fuel pressure regulator. When reading low pressure pull vacuum line. Does it climb?
jag1959 is offline  
 
post #4 of 34 (permalink) Old 07-07-2013, 08:55 AM Thread Starter
Junior Member
 
Join Date: May 2011
Location: Dammam, Saudi Arabia
Chapter: Northeast
Posts: 94
Rep Power: 17
 
Trader Score: 0 reviews
thnaks for the replies,
As i mentioned no engine codes read on my scanning tool. Fuel pressure regulator can be a suspect as jag1959 told, i will look into that. Is it located over the tank under the vehicle?
I didnt try to open fuel tank cap and have a check, may be worth to see that too.

i will work on it and let you know the updates.
M85 likes this.
mbarazeen is offline  
post #5 of 34 (permalink) Old 07-07-2013, 09:13 AM
Play Nice or Don't Play

 
jag1959's Avatar
 
Join Date: Jun 2011
Chapter: Northeast
Year: 1998
Model: Ford Taurus SHO
Engine: 3.4L Yamaha V8
Posts: 14,786
Rep Power: 120
       
Trader Score: 0 reviews
Regulator is on the fuel return rail.

jag1959 is offline  
post #6 of 34 (permalink) Old 07-07-2013, 09:43 AM
Devoted Member
 
Join Date: Apr 2003
Location: Virginia
Chapter: Southeast
Year: 94
Model: Ford Taurus
Engine: 3.8L Essex
Posts: 2,433
Rep Power: 44
 
Trader Score: 0 reviews
If your fuel pressure regulator is on the engine as shown above, you might try removing its vacuum line to see if its wet inside with fuel, if so, replace the fuel pressure regulator.

94 Taurus GL 3.8L PEP204A
99 Ranger XLT 4dr 4.0L 5spd Auto
Payload & Tow Pkg

Details are trifles, but trifles make perfection & perfection is no trifle (Ben Franklin)
Our signature is a sign of a job completed, autograph your work with excellence.
pawpaw is offline  
post #7 of 34 (permalink) Old 07-07-2013, 11:11 AM
Technical Advisor
 
behlinla's Avatar
 
Join Date: Dec 2007
Location: Wisconsin
Chapter: Midwest
Posts: 7,539
Rep Power: 90
      
Trader Score: 0 reviews
Okay, just to be clear do you have the correct 2001 PCM in your car now? Theses issues are with the 2001 PCM?

Also I have to ask the obvious, is the gas tank empty when you have these problems? Fuel gauge reading correctly?

When you checked the fuel pressure and found it low was the engine running or not?

I would change the fuel filter if it's been 50,000 km or more since the last time it was changed.

Make sure you hear the fuel pump run every time you cycle the key to on.
behlinla is offline  
post #8 of 34 (permalink) Old 07-08-2013, 12:10 AM Thread Starter
Junior Member
 
Join Date: May 2011
Location: Dammam, Saudi Arabia
Chapter: Northeast
Posts: 94
Rep Power: 17
 
Trader Score: 0 reviews
Quote:
Originally Posted by behlinla View Post
Okay, just to be clear do you have the correct 2001 PCM in your car now? Theses issues are with the 2001 PCM?

Also I have to ask the obvious, is the gas tank empty when you have these problems? Fuel gauge reading correctly?

When you checked the fuel pressure and found it low was the engine running or not?

I would change the fuel filter if it's been 50,000 km or more since the last time it was changed.

Make sure you hear the fuel pump run every time you cycle the key to on.
1- yes i have the correct PCM now
2- gas tank has no issue , gauge is reading correct
3- i checked when engine running, i opened the cap of the valve on fuel rail, pressed the vale, very less pressure and engine about to die, then get idle when relased
4-fuel filter replacement is due, but i drove this car last night to another city 30km far, i didnt have this issue till i stop at the 3rd trafic signal in that city. i returned back after 3hrs and it worked smooth till i reached. i doubt anything related to heat / engine copartment temperature? what it could be? if fuel filter is the issue, it must have given me truble whole the way.
5- i hear the fuel pump noise every time i turn the key

in my car i see the fuel rail doesnt have a return line. as i remember the filter itself is having a return line. so where can be the regulator located? or am i missing something?

If i want to check supply voltage and relay drive voltage from PCM, how to access the terminals? i am thinking to pull the relay and insert think insulated wire to bring it out and put the relay in place so that i can check it when the issue come, is it the correct practice?

Edit: i opened the gas cap last night to see if any different , in both cases the issue remains the same.
Thanks

Last edited by mbarazeen; 07-08-2013 at 12:14 AM.
mbarazeen is offline  
post #9 of 34 (permalink) Old 07-08-2013, 02:20 AM
Technical Advisor
 
behlinla's Avatar
 
Join Date: Dec 2007
Location: Wisconsin
Chapter: Midwest
Posts: 7,539
Rep Power: 90
      
Trader Score: 0 reviews
Check the regulator next.

I think the fuel system on a 2001 Vulcan might be mechanical return (sort of an oddball year).

Check for fuel pump voltage at the IFS switch in the trunk. Don't rig the relay up like that.
behlinla is offline  
post #10 of 34 (permalink) Old 07-08-2013, 07:46 AM
Devoted Member
 
Join Date: Apr 2003
Location: Virginia
Chapter: Southeast
Year: 94
Model: Ford Taurus
Engine: 3.8L Essex
Posts: 2,433
Rep Power: 44
 
Trader Score: 0 reviews
Quote:
Originally Posted by mbarazeen View Post
1- yes i have the correct PCM now
2- gas tank has no issue , gauge is reading correct
3- i checked when engine running, i opened the cap of the valve on fuel rail, pressed the vale, very less pressure and engine about to die, then get idle when relased
4-fuel filter replacement is due, but i drove this car last night to another city 30km far, i didnt have this issue till i stop at the 3rd trafic signal in that city. i returned back after 3hrs and it worked smooth till i reached. i doubt anything related to heat / engine copartment temperature? what it could be? if fuel filter is the issue, it must have given me truble whole the way.
5- i hear the fuel pump noise every time i turn the key

in my car i see the fuel rail doesnt have a return line. as i remember the filter itself is having a return line. so where can be the regulator located? or am i missing something?


If i want to check supply voltage and relay drive voltage from PCM, how to access the terminals? i am thinking to pull the relay and insert think insulated wire to bring it out and put the relay in place so that i can check it when the issue come, is it the correct practice?

Edit: i opened the gas cap last night to see if any different , in both cases the issue remains the same.
Thanks
OK, good trouble shooting feedback, too bad the gas cap test didn't prove positive, as its an easy fix!!!!. Your answer in #3 above, about the engine idle recovering when you pressed the fuel rail Schrader valve to check fuel pressure, is a good clue.

A few things come to mind that could be causing this.

1) As it seems to happen after a long drive, or in traffic, I suggest again, fuel line vapor lock, from the fuel boiling after a drive in the hot weather your having now in Saudi Arabia. If the problem began right after you filled up with fuel from an off brand, or out of the way fuel station, that was selling sub-standard fuel that didn't have its vapor pressure properly formulated for the temperatures your having this time of year. If you have Chevron/Texaco/Caltex, Shell, or BP gasoline available, maybe try one of them & see if things improve.

2) An aged, weak, failing fuel pump, or pressure regulator assembly, that's likely located in the fuel tank, is having intermittent problems building & holding fuel pressure. Could be a grain of sand that's gotten past the in tank fuel pump "sock" pre-flter and lodged in the pressure regulator, or drain-back valve holding it open so that the pump can't build proper fuel pressure. So perform a proper fuel pressure test, with a gauge connected to the fuel rail Schrader valve test port (where you bled the fuel pressure off in your trouble shoot) & post your fuel pressure Numbers with the engine cold and at idle & at say 2500 rpm, then do it again when the engine is warm & about to stall. EDIT: Also leave the fuel pressure gauge attached to the fuel rail after you turn the engine off, then time & post how long it'll hold fuel pressure & what the fuel pressure number is.

3) A line, or gasket, or seal problem, in the fuel tank, with the fuel pump/pressure regulator assembly, intermittently picking up air & injecting it into the fuel line, or with shifting debris clogging the in tank fuel pump pick up sock pre-filter, so the pump has problems sucking up enough fuel to build pressure.

4) As has been suggested, maybe intermittent low operating voltage to the fuel pump. As has been said, the in trunk fuel pump inertia cutoff switch electrical connector is an easy access test point, to back probe the fuel pump electrical B+ feed, as it'll test most of the electrical wiring to the fuel pump for under load voltage drop.

More thoughts for consideration, keep us posted on your trouble shoot.

94 Taurus GL 3.8L PEP204A
99 Ranger XLT 4dr 4.0L 5spd Auto
Payload & Tow Pkg

Details are trifles, but trifles make perfection & perfection is no trifle (Ben Franklin)
Our signature is a sign of a job completed, autograph your work with excellence.

Last edited by pawpaw; 07-08-2013 at 07:52 AM.
pawpaw is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Taurus Car Club of America : Ford Taurus Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Power Steering Pump Replacement + High Pressure Line Monsoon Suspension, Handling and Brakes 6 03-31-2019 09:17 PM
ERG? or DPFE? causing high RPMs CBrotherton Maintenance and Repair 6 06-29-2013 11:47 PM
unusual engine related noise (fuel pressure regulator?) chris87654 Engine and Drivetrain 2 06-21-2013 07:15 PM
Why won’t my car start? - Comprehensive No-Start Troubleshooting Guide behlinla Maintenance and Repair 1 01-05-2013 11:52 PM
How to Understand and Diagnose Misfires Sam Solutions to Common Problems and 'How To' Articles 0 11-12-2012 02:37 PM

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome