Reply
 
Thread Tools Display Modes
 
Old 10-11-2016, 06:44 PM   #1
Senior Member
 
bemerritt's Avatar
 
Join Date: May 2015
Location: San Clemente, CA
Posts: 548
7.3 Problems going up hills, fuel filter?

Coming back from a trip this past weekend and it seemed as if the engine would shut down when working hard going up hills. The harder it got pushed, the worse it got. Eventually I had the van towed to the closest Ford service center.

As some of you may know, I recently had 4x4 done, so after talking with them, they drove up to make sure it wasn't a programming issue or having to due wit switching to 4.10 gearing.

At the dealer, they diagnosed a intermittent cam position sensor, so that was changed out.

On the drive home, the van fired up fine and seemed to get up to speed ok, but when going up a hill it seems to just crap out, as if it is not getting enough fuel.

Does this sound like a fuel filter problem? Figure it could be at the filter or at the pickup tube in the tank. The tank was trimmed for the conversion.

Just starting my research on the matter, but it seems easy enough to replace the filter myself. But anyone have a good diesel mechanic in the OC area?

Thanks for any input
__________________

bemerritt is offline   Reply With Quote
Old 10-11-2016, 06:48 PM   #2
Site Team
 
BroncoHauler's Avatar
 
Join Date: May 2007
Location: Southern New Mexico
Posts: 8,827
I've had a CPS issue before on my 7.3 Excursion. Truly maddening as it will run fine and then stall the engine without being able to restart. You can crank and crank with no result, and then later on it will fire right up.

Never did experience issues with going up steep hills though.

Shouldn't be the fuel filter in the fuel bowl, though maybe the fuel pickup in the tank is the issue?


Herb
__________________

__________________
SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.
BroncoHauler is offline   Reply With Quote
Old 10-11-2016, 07:32 PM   #3
Senior Member
 
Join Date: Apr 2007
Location: Fruita, Colorado
Posts: 1,173
It does sound like a fuel delivery problem. Any codes?
__________________
Desert Solitaire
2003 7.3L EB 4x4
Denver Fleet 4x4 conversion
saline is offline   Reply With Quote
Old 10-12-2016, 02:30 PM   #4
Member
 
Join Date: May 2016
Location: Texas
Posts: 52
Best case scenario is your underhood fuel bowl filter is dirty. Not hard to change, but I would recommend 2 things to all 7.3 van owners.
1. Use only the factory Motorcraft filters that are separate from the cap(2 piece). They filter better and are easier to install/remove than the comparable one piece filter/cap combo units from Napa, AZ, etc. Trust me, if you needed to replace filter at night, on the road or trail, you want the 2 piece!
2. It is important that the gasket goes on correctly. They come in a skinny bag which keeps them in an elongated oval shape, so it is also a good idea to remove gasket from bag and allow to return to round overnight. No matter what, don't allow your service tech to throw away your filter housing cap, even if they use a 1 piece replacement.

Below your CPS, there is an EBPS (exhaust back pressure sensor) and tube. A clogged tube is fairly easy to clean and can effect fueling as well as bad sensor. Under certain problematic conditions, it is possible for your computer to put the 7.3 into limp mode. I am not sure if this is what happened though. After fuel filter is changed, and obvious items (like air filters, fluid levels, etc.)are checked out, I highly recommend you have your fuel pressure tested under load with a quality FP gauge. That will help you determine where to go from there. If FP still tests low under load, you have clogged cartridge screens inside fuel tank sending unit, weak or failed fuel pump, or other fuel system leaks (which would show up on your driveway dripping from underneath rear of engine). Worst case scenario would be that you have one of the factory tanks that is delaminating internally like mine was. If so, all other screens and filters need to be removed/replaced as well as the tank. Do not continue driving/revving a 7.3 if you suspect extremely low FP. Things can get expensive if you do. Ask around for a real good shop that knows their way around the 7.3 Super Duty trucks. Most things are similar, except the trucks all have plastic tanks. If low fuel pressure is the problem, then tell the techs about the delamination possibility if they've only worked on trucks before. There are other possibilities that a qualified diesel tech can scan/test for as well to prevent throwing mucho parts at the problem. Hope that helps some.
VOODOO7.3 is offline   Reply With Quote
Old 10-12-2016, 02:36 PM   #5
Senior Member
 
bemerritt's Avatar
 
Join Date: May 2015
Location: San Clemente, CA
Posts: 548
Thanks for the advice. I had the filter replaced last night and it drove ok today to work. Was able to accelerate up to about 80 going up the biggest hill. It still seems to be lacking a little bit of oomph though. I don't remember having to floor the gas pedal to do this in the past.

I may switch gas tanks as I want a bigger one anyways. Is there a user way to test fuel pressure under load? I have been meaning to get one of those sensors that you can connect to bluetooth to monitor temps and whatnot, anything like that that can monitor pressure?
bemerritt is offline   Reply With Quote
Old 10-12-2016, 02:42 PM   #6
Senior Member
 
rallypanam's Avatar
 
Join Date: Feb 2013
Location: San Francisco/Nevada City
Posts: 3,638
Borrow a good code reader and check a few things.. Fuel pressure and injector pressure. those probably aren't the exact terms, but here's what little I know:

1. Low fuel pressure can cause this, it can be from clogged lines, clogged filter, crappy pump, etc. If you put a reader on it and the fuel pressure at the motor is good, it's probably not it.
2. HPOP powers the injectors, so check that. There's the HPOP itself, a sensor, and a few other components. If it doesn't provide good pressure, you'll have issues. If it doesn't have above a certain threshold of pressure, the injectors won't even fire and you won't be able to start the van.
3. Check injectors themselves.

Look on some of the Ford truck forums. Way more knowledgeable people there, and the motors are close enough to be able to do most troubleshooting.
rallypanam is offline   Reply With Quote
Old 10-12-2016, 03:01 PM   #7
Senior Member
 
bemerritt's Avatar
 
Join Date: May 2015
Location: San Clemente, CA
Posts: 548
Thanks, looks like I should just pony up for the "AutoEnginuity Total Ford Enhanced Bundle"

Having a 98 and being invested in it for the long haul makes it seem like a worth while purchase
bemerritt is offline   Reply With Quote
Old 10-12-2016, 04:41 PM   #8
Senior Member
 
shenrie's Avatar
 
Join Date: Nov 2012
Location: boise idaho
Posts: 2,054
Garage
Had to replace my hpop a couple of weeks ago. First sign of an issue was low power. Called my mechanic and he asked for ipr's and icp pressures. I checked scanguage and reported back. He instantly replied and said I had a leak. He said either a leaking oring on one of the injectors or the hpop was bad. Took the van to him an he checked the cheaper fix first and pressure tested the fuel rails. Both sides pumped right up to 3k and held ...replaced hpop and power is back.

If you have a scanguage these are the numbers he gave me in the range they should be.

Quote:
Icp at idle 475-490
Ipr% at idle 9-11%

Icp at wot in neutral 1100-1200
Ipr% wot in neutral 18-21%

Icp under hard acceleration 2400-2700
Ipr% under hard acceleration 35-40%
__________________
"understeer is when you hit the wall with the front of your car, oversteer is when you hit the wall with the rear of your car, horsepower is how hard your car hits the wall, and torque is how far your car moves the wall."
shenrie is offline   Reply With Quote
Old 10-13-2016, 06:28 AM   #9
Member
 
Join Date: May 2016
Location: Texas
Posts: 52
Quote:
Originally Posted by bemerritt View Post
Thanks for the advice. I had the filter replaced last night and it drove ok today to work. Was able to accelerate up to about 80 going up the biggest hill. It still seems to be lacking a little bit of oomph though. I don't remember having to floor the gas pedal to do this in the past.

I may switch gas tanks as I want a bigger one anyways. Is there a user way to test fuel pressure under load? I have been meaning to get one of those sensors that you can connect to bluetooth to monitor temps and whatnot, anything like that that can monitor pressure?
bemerritt, Yes, you can buy two fuel line quick (a/c type) fittings from O'Reilly's or similar, about 6' of 3/8" fuel injection hose, T, & clamps and mechanic's fuel pressure gauge. Make it temporarily "T" in between pump and engine and temporarily attach to door mirror for testing under load. A more permanent solution is to buy the bowl fitting and diesel rated Schraeder valve that stay on bowl. Gauge attaches to that, when you need it. Here are those fittings:

1/8" NPT straight pressure port adapter.

Fuel rated Schrader valve for testing fuel pressure. Rated for Diesel or Gas.

No scanner or app will tell you FP. You can see a-lot of other engine parameters with Torque Pro app and Wifi OBD2 adapter for @ $30 total, naturally AE software has more capabilities (like injector buzz testing, etc.) and is much more expensive. Cheers!
VOODOO7.3 is offline   Reply With Quote
Old 10-13-2016, 10:30 AM   #10
Senior Member
 
bemerritt's Avatar
 
Join Date: May 2015
Location: San Clemente, CA
Posts: 548
Yeah, after endless amounts of reading last night, fuel pressure seems to be more of a challenge to read. Ordered the scangauge to read ICP and that will be here tomorrow.

Definitely feels like a fuel supply problem. Confirmed today at the beginning of the hill it was doing great again and then it just starts losing power at the top. Even when I get to the top and start going flat it seems to take a while to recover.

Late next week I'll be changing out fuel tanks and cleaning the pickup. Apparently there is a valve in there that some years have that has a tendency to gunk up. So hopefully this takes care of it.

Is there any potential damage I am doing by driving the van until then? Seems to be running fine otherwise.
__________________

bemerritt 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 04:32 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.