help with fuel pressure numbers
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
help with fuel pressure numbers
Guys, my 2000 v-10 has been going thru a lot of gas lateley 
, had a friend scan iot...said it was pushing too much fuel thru. i got a actron fuiel pressure tester to double check it going by info from a post from Art Krewat. At idle,engine running, should see 28-30....i have 45 psi. with engine off,key on,should see 38-40...i have 38. couldnt test with engine running and vacuum disconnected from fuel regulator (and plugged)...so i went to next step...pedal to floor should be above 35 , i have 40+ couldn't really see guage from cab as well as i thought. could this point to a fuel regulator problem? thanks guys....Britt
, had a friend scan iot...said it was pushing too much fuel thru. i got a actron fuiel pressure tester to double check it going by info from a post from Art Krewat. At idle,engine running, should see 28-30....i have 45 psi. with engine off,key on,should see 38-40...i have 38. couldnt test with engine running and vacuum disconnected from fuel regulator (and plugged)...so i went to next step...pedal to floor should be above 35 , i have 40+ couldn't really see guage from cab as well as i thought. could this point to a fuel regulator problem? thanks guys....Britt
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Art,thanks for chiming in...i went out a few minutes ago and checked the fuel pressure with the regulator vaccum line disconnected and line plugged. the fuel pressure was 50 psi. i spoke with a parts guy at the local ford dealership. He said that if the fuel pressure reg was going out, the truck would be nearly un-driveable. I dont know what the symptoms are of this problem, my friend who scanned it told me that it seemed to be pushing too much fuel thru....the only issue ive got with the truck aside from this is its started to go thru oil a little more than usual. normally i'll go thru a 1/2 to 3/4 quart between changes....last week its gone thru a quart. pvc is clear....it rattles....and both pvc and elbow was changed out in last year. also recently did the sct3 87 economy tune from mike at 5 star. only picked up 0.10 mpg increase 
last mpg check figured at 8 mpg, have been averaging around 11.7....thanks for any ideas Britt
last mpg check figured at 8 mpg, have been averaging around 11.7....thanks for any ideas Britt
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,562
Likes: 424
From: Long Island USA
OK, 50 is TOO HIGH. 45 at idle with the vacuum connected is TOO HIGH.
Connect a hose to that vacuum nipple on the regulator, apply vacuum, and watch the fuel pressure. It should drop as you apply vacuum. If it doesn't, and certainly doesn't go below 45, something is wrong with the regulator.
Before 2002, the OBD-I systems wouldn't really complain about fuel mix until it gets WAY out of whack (+-40%) https://www.ford-trucks.com/forums/5...t-come-on.html
With the system running in closed-loop even at WOT, it'll monitor the O2 sensors and trim the mix up to a point, making up for the increased fuel pressure. I bet if you had a scan tool and watched the fuel trims, they'd be way into the (-) direction as far as they can go.
And for the oil consumption, a rich mix will wash the oil from the cylinder walls, and burn off the oil.
Again, if you have 50 psi with no vacuum, and 45 with, that's way too high.
Connect a hose to that vacuum nipple on the regulator, apply vacuum, and watch the fuel pressure. It should drop as you apply vacuum. If it doesn't, and certainly doesn't go below 45, something is wrong with the regulator.
Before 2002, the OBD-I systems wouldn't really complain about fuel mix until it gets WAY out of whack (+-40%) https://www.ford-trucks.com/forums/5...t-come-on.html
With the system running in closed-loop even at WOT, it'll monitor the O2 sensors and trim the mix up to a point, making up for the increased fuel pressure. I bet if you had a scan tool and watched the fuel trims, they'd be way into the (-) direction as far as they can go.
And for the oil consumption, a rich mix will wash the oil from the cylinder walls, and burn off the oil.
Again, if you have 50 psi with no vacuum, and 45 with, that's way too high.
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Art, just got your reply....thanks,picked up a new regulator today,will try the vaccum trick as soon as i can find my vaccum pump
.....gotta clean my garage out!!! will have time to swap it out this weekend. i'll get back to you then....this has probably been an issue for a while, just wont throw a code with obd-1 system. thanks again Britt
.....gotta clean my garage out!!! will have time to swap it out this weekend. i'll get back to you then....this has probably been an issue for a while, just wont throw a code with obd-1 system. thanks again Britt
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Art...an update...found my vac gauge. hooked it to pressure reg. pulled vaccum down to 40 and it held...that was with engine running. however with the engine off and key on had 22 pounds pressure i applied vaccum and the pressure slowly dropped to 20 pounds. i've probably got this all screwed up... i also checked my tailpipe for gas residue,it was wet with gassy oil residue. should i check with engine off or running? I appreciate the advise, does this still point to bad regulator? Thanks Britt
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Art, forget the above numbers....didn't have the guage screwed tight 
. with engine running, i've got 50 psi. I unplugged and capped the line to the pressure reg. then hooked my vaccume guage to the nipple pulled 15 pounds of vaccum on the guage and the fuel pressure dropped from 50 to 45 psi. there was a little fluctuation on the guage. exaust is still gassey....thanks
. with engine running, i've got 50 psi. I unplugged and capped the line to the pressure reg. then hooked my vaccume guage to the nipple pulled 15 pounds of vaccum on the guage and the fuel pressure dropped from 50 to 45 psi. there was a little fluctuation on the guage. exaust is still gassey....thanks
Trending Topics
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
update
Finally got around to changing out the fuel pressure reg. on my v-10. wasnt that hard....just folllow the procedure in my chilton manual. gotta check the pressure in the morning....seat of the pants seems to be better though. hope this is it, was getting gas and oil residue out of the tailpipe and mileage went to hell....
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Fords to Drive Before You Die
Joe Kucinski
3 Best / Worst Features Of The 2025+ Ford Expedition
Brett Foote
10 Ways Ford is LOSING to the Competition
Joe Kucinski
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Guys, update...fuel pressure reg swapped out.truck drives better. before i swapped it out i had fuel pressures up to +35 (useing a friends data logger scanner) now fuel pressures are in range of -3 to + 1 fuel mileage seems to be a little better to. thanks
Thread Starter
|
Senior User
Joined: Nov 2007
Posts: 195
Likes: 0
Art...thats "trim"....oops,he's reading it to me as we were driving. should i unhook the battery to reset the computer to clear it out? btw, i'll try the vac. test on my 4x4 today. i'll let you know, thanks
Thread
Thread Starter
Forum
Replies
Last Post
gvrangr98
Explorer, Sport Trac, Mountaineer & Aviator
15
Mar 16, 2010 09:28 PM
