The Diesel Stop banner
1 - 20 of 34 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter · #1 ·
So Mable, my 1987 Ford F250 6.9l Diesel has started running rough (all of a sudden). Some of the things I will mention happen often. Some are new, and I will be sure to let you know which is which. I really need some help figuring this thing out. The rough running started last week. She was running just fine, starting hard first thing in the morning (like always), but once we got through the initial startup, she ran great all the way to work. I was "VERY" low on fuel and stopped to fill up that morning (around 5:00am). I put about 5 ounces of Diesel Kleen for the 16 Gallons of diesel that it took to fill her up. She ran great all the way to work. Took her out during lunch break for a 20 minute round trip to burger king. No problems then either. At 4:30pm, I fired her up and headed to run some errands on the way home. We took the freeway (keeping it around 60mph as always). When I got to my first stop (tractor supply co), I came to an idle in the parking lot and sat their vibrating. I thought the cab of the truck was just going to shake right off the frame. I noticed a significant amount of white smoke steady pouring out of the tail pipe. I'd sometimes get white smoke, at speed, if I hit the gas, or when excellerating from a stop, but it never continually pours out. I shut her down, and went in to shop. I waited about 30 minutes before I came back out, and I checked the oil. It was right at the full line. I talked with a friend of mine who owns diesels and he said that white smoke could be indicative of a coolant leak, and that I should wait for the truck to cool down, pop the radiator cap, start the truck up, and look for bubbles (lots and lots of bubbles). I did this, the coolant level was good, and there wasn't a single bubble. I'm including pictures of the engine compartment and a couple of videos in this post, mostly so you guys can tell me what I'm looking at/for. I'm really new to this and don't know jack about diesel engines, though I'm learning. For instance, last fall I replaced the glow plugs and the fuel rail (it was leaking terribly). I also cleaned the injectors and replaced all the seals one them (also leaking terribly). She ran like a top after. I get 16MPG all the time, whether it's empty or filled with 2 pallets of sod (I do landscaping on the side). Lately though (the last couple fill ups) I've been getting closer to 14MPG. Also, since I've owned her, she's been rough starting. You can see it in the video. She'll start up after the first turn over, but dies about 5 seconds in, then I have to turn it over about 4-5 times before she'll get up and running again, then hold the gas for a few seconds, keeping her at around 1500rpm until it smooths out, after which I let off the gas and she drops to high-idle for about 3 minutes, then to 800 rpm, and it's off to work! So... Why is she running so rough? What do I look for. Some have told me there could be air in the fuel. Some have said I might need a new lift pump. I'm concerned that it might be the oil pump. The oil level is good, but how do I know if the oil pump is doing it's job (especially given the squirreliness of the guages, which you'll see in one of the videos). Looking for all the suggestions you can lend me. I just need to get her up and running again so I can continue my landscape work. Money is an issue, so hopefully I'm not looking at hundreds of dollars. Thanks in advance for your help guys!

You can view the videos and pictures of Mable at the following link: http://1drv.ms/1T0RQVX

Thanks guys!!
 

·
Registered
Joined
·
187 Posts
I could not see the video. I only got the audio which sounds like air. Your photos have no real focus, aside from the corroded battery terminals and some darkened injector lines. If your injector line connections have become darker or coated with shmootz since you have replaced them; they are leaking. Air is less dense than fuel, so if fuel is leaking air will also. The battery terminals need to be cleaned or replaced. You need more direct, closer, photos of the injectors, filter, and fuel lines to determine leakage over the net. Corroded or loose electrical connections will cause all kinds of problems.
 

·
Registered
Joined
·
3,553 Posts
To address your WTS, which has nothing to do with engine after it's running.

The Black grounding wire has to be on a tight and clean ground for the GP controller to work. Ground wire is usually on the intake stud close to the firewall.

To check the individual glow plugs, use a 12V test light, hook the long lead to battery POS, pull the wire off each glow plug, touch probe to GP terminal, if the light, lights, the GP is good.
 

·
Registered
Joined
·
3,553 Posts
Oil pressure. Cold engine at idle, 10 to 40 PSI. Hot engine idle, 5 to 10 PSI. Hot engine 1800 RPM, 40 to 70 PSI.
Rarily does the oil pump ever go bad, maybe around 400,000 miles, it is a gear pump.
 

·
Registered
Joined
·
3,553 Posts
She'll start up after the first turn over, but dies about 5 seconds in, then I have to turn it over about 4-5 times before she'll get up and running again, then hold the gas for a few seconds, keeping her at around 1500rpm until it smooths out, after which I let off the gas and she drops to high-idle for about 3 minutes, then to 800 rpm, and it's off to work!
Above said, it's typical of air intrusion, air along with fuel has to be worked out before smooth running. White smoke is air intrusion.

Your fuel is draing back to tank, to confirm that before a start, remove the fuel filter, if it's half full, then you have air intrusion, check the seal from the lift pump to filter, it gets hard from heat, a little bump doing work and it will let air in, not fuel out. same thing, the line from filter to IP fuel inlet. The hardened seal is difficult to remove, use a dental pick to pick at it.

You changed all the rubber lines between injectors, any wetness on them is a leak, leaking will let air in after shut down.

That short rubber hose from hard line to lift pump is another source of air intrusion, it gets cracked. Replace it. Use only diesel rated hose.
 

·
Registered
Joined
·
11,887 Posts
To check the individual glow plugs, use a 12V test light, hook the long lead to battery POS, pull the wire off each glow plug, touch probe to GP terminal, if the light, lights, the GP is good.
Not a valid test at all. Glow plugs 101---- If the light lights the glow plug *may* be OK or may not. The glow plug may have zero resistance which will allow the light to light but with no resistance the plug will not heat. The reliable check is with an Ohm meter.
 

·
Registered
Joined
·
3,553 Posts

·
Registered
Joined
·
11,887 Posts
Just the opposite, if either end of the heating coil is burned off, you'll have infinite resistance. But if the coil is shorted internally to the body or whatever the light will light but no heat.
 

·
Registered
Joined
·
86 Posts
Just the opposite, if either end of the heating coil is burned off, you'll have infinite resistance. But if the coil is shorted internally to the body or whatever the light will light but no heat.
I don't know enough about their internal construction to say if it possible for them to short when they burn out, but I assume that is what the fusible link is for.

Either way, I like to check them with an ohm meter so I can see "how bad" they are. That is, I'm not sure a test light would show weak plugs.

The last time I replaced my glow plugs, all of them had the same resistance, plus or minus a couple of tenths except one was open and another was about an ohm off (I don't remember if it was high or low). The one with the different resistance didn't get nearly as hot as the others.

Though really, for a quick test, the light is easier and faster for most people...
 

·
Registered
Joined
·
86 Posts
It looks like your check engine light came on at the same time your oil pressure gauge went whacko. Also, since giving the engine some fuel will clear your light and the wacky gauge at the same time, I would guess you have a bad oil pressure sender or wiring. My money is on the sender...

I will also third Zork and Bill, sounds like air intrusion...
 

·
Registered
Joined
·
11,887 Posts
Either way, I like to check them with an ohm meter so I can see "how bad" they are. That is, I'm not sure a test light would show weak plugs.

The last time I replaced my glow plugs, all of them had the same resistance, plus or minus a couple of tenths except one was open and another was about an ohm off (I don't remember if it was high or low). The one with the different resistance didn't get nearly as hot as the others.
Right, that's been the case here and elsewhere often. A test light will light brightly because there not enough or no internal resistance and of course the plug doesn't heat.
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #12 ·
Ok... So I believe I've identified that there is a diesel leak (very small) where the line running up to the fuel filter leaves the lift pump down below. I'm guessing that's where air is getting in. I have three questions. First, does anyone have, or know where I can find, a part number for the seal I need to replace? Most diesel parts places don't go back that far. Secondly, is there something I can just wrap, or slather around the outside to seal it in lieu of taking it apart and replacing the seal (if I can't find the part number / replacement part). And finally, I really need to get back to work around the house and need the truck to get supplies and make a dump run. Is it going to cause damage to run that engine with air in the fuel? She runs ok at highway rpm's, just idles really rough. Can I put her to work (gently) until I get her fixed up? Thanks guys!
 

·
Registered
Joined
·
3,553 Posts
cut a piece of 3/8" ID hose off a 1/4" long, use a dental pick to get the old out. there called olives. stuff a couple of fat orings in there ace hardware has orings. dieselorings.com has them most any hyd.shop has them.
 

·
Registered
Joined
·
17,604 Posts
Harbor Freight has Viton O rings. I used 2 stacked- no leak going on 5 years now.
 

·
Registered
Joined
·
11,887 Posts
(if I can't find the part number / replacement part).
If you're referring to the black rubber sleeves that go over the steel lines, you won't find a part number because they are a commonly used seal used on many low pressure lines on diesel systems. Measure the OD of the lines, most injection shops or parts houses will have them. Can't remember for sure, but I think one line is 1/4" and the larger one is 3/8". Worse comes to worse, buy short pieces of fuel hose. Hose goes by ID, tubing by OD.
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #16 ·
So what about running it until I get it fixed? Is that safe or will it do damage? Also, somewhat related question... Do they make a fuel filter that, with built in water separator, that will cut my truck? Thanks!
 

·
Registered
Joined
·
3,553 Posts

·
Registered
Joined
·
3,553 Posts
Ok... So I believe I've identified that there is a diesel leak (very small) where the line running up to the fuel filter leaves the lift pump down below. I'm guessing that's where air is getting in. I have three questions. First, does anyone have, or know where I can find, a part number for the seal I need to replace? Most diesel parts places don't go back that far. Secondly, is there something I can just wrap, or slather around the outside to seal it in lieu of taking it apart and replacing the seal (if I can't find the part number / replacement part). And finally, I really need to get back to work around the house and need the truck to get supplies and make a dump run. Is it going to cause damage to run that engine with air in the fuel? She runs ok at highway rpm's, just idles really rough. Can I put her to work (gently) until I get her fixed up? Thanks guys!

Here are the Part Numbers.
Search results for: 'hard line seals'

Parker 7-006 60VL-6 Viton sleeve 3/8" requires one from lift pump to filter. $2.54
Parker 7-005 60VLV Viton sleeve 5/16" requires two from filter to IP. $2.54 ea.
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #19 ·
Got my O-rings

Here is a filter with water seperator if your interested. I'll even send along the steel line seals. PM Me please.

http://www.thedieselstop.com/forums/f42/88-94-fuel-filter-housing-assembly-523673/
Checked out the pics on your linked post. I am not sure this is what I'm looking for. I'm told that there is a fuel filter out there that looks like mine on top, but on the bottom has a clear (glass?) section wherein you can see if there is water (air) in the fuel. Have any of you heard of such a thing? Also... picked up the HNBR variation of the O-rings offered at Harbor Freight. I chose these over the Viton because of the statements about handling higher temp fluctuations and being resistant to more chemicals. It seemed a better fit for my current project. Let me know if there is some reason I'm not seeing that I shouldn't use these and instead use the Viton. I'm going to do this work tomorrow morning. I'm guessing I just break the line loose top and bottom, remove the old seals, replace with new seals, and reinstall the line. Then I figure I'll have to start it up and bleed the air out. Is that right? Where would be the best place to bleed the air out. Can I use the Bicycle tire looking valve on top of my fuel filter, or do I need to crack open the injectors lines? Is there anything else I should be aware of or have on hand prior to accomplishing this task? Thanks a bunch guys!
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #20 ·
Not a valid test at all. Glow plugs 101---- If the light lights the glow plug *may* be OK or may not. The glow plug may have zero resistance which will allow the light to light but with no resistance the plug will not heat. The reliable check is with an Ohm meter.
Can you give me a little more guidance on what to look for with the Ohm meter? I have one and would like to do this test.

Thanks!
 
1 - 20 of 34 Posts
Top