Go Back   F150online Forums > Powertrain & Mechanical > V8 Engines
Sign in using an external account
Register Forgot Password?


Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-14-2009, 09:25 AM
Senior Member
 
Join Date: Sep 2008
Location: OH
Vehicle: 1999 Ford F150
Posts: 312
bad fuel pump or injector/s ?

This is on my 97 F150 xlt 4x4 w/4.6V8 automatic. Truck has 115k miles.

So sunday I was driving on the high way going about 50-65 mph. All of a sutton the rpms dropped like the car was going to shut off. Check engine light flickered for a second and the car cought itself.
It did it like 2 times and then didn't do it again. Drove fine the rest of the day.

Next morning drove it to work. No issues drove like it always has. On the way home though it did it 3 times in a row and then finally just shut the truck off. I had to coast into the EM lane. Tried to start it but no such luck. Just cranks but doesnt start and run. Had to have it towed home.
Got home and the tow driver got in the truck put the key in and it strated up. He was like hmmmm, and me too.

So am I looking at the fuel pump going bad or is bad already?
Fuel injectors?
Or something else?

The truck started up fine all days, idled fine too. Does now too.

No check engine light is on now, and everytime it acted up the light would come on for a split second then
go right back off.

Spark plugs are all new and motorcraft. Only one needs to be replaced on the passenger side back. It's a
pitta to get to. Dont think a bad plug would cause my issues though. Also has a new fuel filter.

Anything else that would cause my symptoms?
I was thinking maybe fuel pressure regulator, but the truck should still run, just not good correct.
If that was it, it would run rouph all the time not just all of sutton.

Thoughts/suggestion.

Whats the easiest way to change the pump. ( have a full tank of gas right now 24g)

Thanks,
Reply With Quote
  #2  
Old 04-14-2009, 09:40 AM
Technical Article Contributor
 
Join Date: Oct 2005
Location: MI
Vehicle: 1998 Ford F150 5.4L 4X4
Posts: 25,636
Quote:
Originally Posted by Midnightride42 View Post
This is on my 97 F150 xlt 4x4 w/4.6V8 automatic. Truck has 115k miles.

So sunday I was driving on the high way going about 50-65 mph. All of a sutton the rpms dropped like the car was going to shut off. Check engine light flickered for a second and the car cought itself.
It did it like 2 times and then didn't do it again. Drove fine the rest of the day.

Next morning drove it to work. No issues drove like it always has. On the way home though it did it 3 times in a row and then finally just shut the truck off. I had to coast into the EM lane. Tried to start it but no such luck. Just cranks but doesnt start and run. Had to have it towed home.
Got home and the tow driver got in the truck put the key in and it strated up. He was like hmmmm, and me too.

So am I looking at the fuel pump going bad or is bad already?
Fuel injectors?
Or something else?

The truck started up fine all days, idled fine too. Does now too.

No check engine light is on now, and everytime it acted up the light would come on for a split second then
go right back off.

Spark plugs are all new and motorcraft. Only one needs to be replaced on the passenger side back. It's a
pitta to get to. Dont think a bad plug would cause my issues though. Also has a new fuel filter.

Anything else that would cause my symptoms?
I was thinking maybe fuel pressure regulator, but the truck should still run, just not good correct.
If that was it, it would run rouph all the time not just all of sutton.

Thoughts/suggestion.

Whats the easiest way to change the pump. ( have a full tank of gas right now 24g)

Thanks,
So you don't want to test anything ? Just throw parts at it ? - We suppose to guess which parts to throw at it?

You have something against diagnostics lol.

Well, I don't so here's what yuh do, -

You might have a DTC in memory, check that first/ then pressure + regulator.

So how old is the filter exactly? - And change that plug, geeeze..
Reply With Quote
  #3  
Old 04-14-2009, 10:50 AM
Senior Member
 
Join Date: Sep 2008
Location: OH
Vehicle: 1999 Ford F150
Posts: 312
Quote:
Originally Posted by jbrew View Post
So you don't want to test anything ? Just throw parts at it ? - We suppose to guess which parts to throw at it?

You have something against diagnostics lol.

Well, I don't so here's what yuh do, -

You might have a DTC in memory, check that first/ then pressure + regulator.

So how old is the filter exactly? - And change that plug, geeeze..
nothing against testing!!!
checkign the DTC is going to be hard since I have no scanner and the truck is parked at home right now.

I was only guessing the fuel pump since it's not a consistant thing and has gotten worse over the few days. Plus after it sat for about an hour it worked again.

The fuel filter has maybe 1k miles on it. Got it changed over the winter.

I plan to change that plug. I just dont think it would cause the truck to die while driving at a constant speed and then not let it start back up but will later on.

What pressure should I be looking for with the truck in part and running? Or how should I go about checking the pressure? Like I said it idles fine.

Testing the fuel pressure regulator, how to test it, and what to look for?

Thanks!
Reply With Quote
  #4  
Old 04-14-2009, 12:53 PM
Senior Member
 
Join Date: Oct 2007
Location: farmington hills, MI
Vehicle: 1997 ford f-150
Posts: 3,439
Send a message via AIM to shifty_85 Send a message via MSN to shifty_85
haynes manual says...... fuel PSI at idle vac. hose attached 30-45 PSI vac. hose detached 40-50PSI.

haynes also says. use a stethoscope or screwdriver and put it on the injector and it should make a steady clicking sound that rises n falls with engine RPM.

you could also crack the fuel line before the fuel filter turn the key foward and see what ya got but the fuel pressure test would prob be better.

im not sure how to do it but i know with a voltometer you can check the ohms on the injectors. maybe jbrew knows how to do it.

also do a fuel amount test or somthing i forget what its called its were you open the purge on the gauge and pour it into the a bottle it should fill a 1/4 of a 2 liter in about 5 seconds or somthing not to long *Hey look college is paying off for me!!!*

Last edited by shifty_85; 04-14-2009 at 12:56 PM.
Reply With Quote
  #5  
Old 04-14-2009, 06:27 PM
glc glc is online now
Senior Member
 
Join Date: Dec 2006
Location: Joplin MO
Vehicle: 2003 Ford F150
Posts: 29,086
Can you drive it to a parts store? Most of them do free scans.

Otherwise, this is a cheap usable scanner:

http://www.amazon.com/gp/product/B001LHVOVK
__________________
2003 F-150 XL RCSB 2wd 4.2 M5OD 3.55 LS
Reply With Quote
Old 04-14-2009, 06:27 PM


 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


All times are GMT -4. The time now is 04:47 PM.





This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company
 
Contact Us Advertising Privacy Statement Terms of Service Jobs Forum Text Archives
Emails & Contact Details