# '99 7.3 runs good then loses power



## SharpBlades (Sep 13, 2009)

My '99 f-250 7.3 is giving me some trouble.

It started a couple weeks ago, The truck had sat for 2 days, I went to take it out and upon starting it almost immediately died. The fuel bowl has been leaking (I need to get the o-ring kit and install it) so I figured that i just didn't give enough time to re fill the fuel bowl. So I cycled it a couple times and started it. 

It ran fine for about 5 minutes in the driveway so I took off and got about 2 miles and it started to lose power almost like it wasn't getting any fuel the SES light also came on... I couldn't remember if I treated the fuel last time I filled up so I added some diesel 911 to the tank, let it sit, and started it about 30 minutes later. It ran great, no SES light... not one hiccup.

Last week I went to start it, and again forgot to cycle the key a couple times and died in the driveway just like the first time. I cycled the key a couple times and she started fine and I drove about 150 miles with no problem.

This past sunday, I filled it up and made sure the fuel was treated since we are expecting lows of -7 this week... We got snow monday and my driver took it out and plowed a 5 hour shift without any problem. He parked the truck inside yesterday and took it out again this morning for another shift. 

I got a call while he was at his last account that the truck was acting up, SES light, low power even with accelerator all the way down, coming back to the shop he said he could only get it up to 30mph. I was there at the shop when he pulled up. There was no smoke... we turned it off then started it back up immediately, the SES light was out and it ran fine. 

I don't have a scanner that will read the codes but I might be able to have my cousin scan it. 

I am not very knowledgeable about diesels, so I'm not sure where to start troubleshooting. 

The only thing that I can think of is the fuel bowl leak which might explain dying at startup after the truck has sat for a couple days, but I'm stumped why it acted up this morning.

Any ideas of what might be wrong would be appreciated. And my appologies if any of my post is incoherent... I'm running on 2 hours of sleep


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## Antlerart06 (Feb 28, 2011)

blowed out O ring on the fuel filter should been replace when you notice a leak Not later


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## SharpBlades (Sep 13, 2009)

Antlerart06;1573010 said:


> blowed out O ring on the fuel filter should been replace when you notice a leak Not later


I know it should be... I'm waiting on the kit. It's the bowl o-ring(s) that are leaking not the big filter o ring


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## Milwaukee (Dec 28, 2007)

Hope you didn't ruin $1600 injectors from low fuel pressure plus AIR in fuel system.

Fix that diesel leak when you see ASAP!

Find someone with scanner that will work with diesel to find what code for.


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## Antlerart06 (Feb 28, 2011)

Milwaukee;1573083 said:


> Hope you didn't ruin $1600 injectors from low fuel pressure plus AIR in fuel system.
> 
> Fix that diesel leak when you see ASAP!
> 
> Find someone with scanner that will work with diesel to find what code for.


You said it I had leak from drain plug in middle night plowing snow I was lucky only kock out 2 injectors


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## fordtruck661 (Feb 26, 2011)

Here you go just order it and got it done.. should only take 2 to 3 hours if you really take your time. Make sure you replace your fuel filter at the same time

http://www.riffraffdiesel.com/mm5/m...uct_Code=GZ-7-003&Category_Code=F731-FS-ORING


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## SharpBlades (Sep 13, 2009)

My cousin scanned it and it didn't show a code but he agreed that the fuel bowl seal is likely the culprit. I've ordered the o rings.

I'm thinking that if it acts up again I'll have the driver turn off the truck and cycle the key a couple times to re prime the system then continue. I know it's not ideal, but we are expecting another 12"+ within a couple hours. 

Will I ruin the injectors by having him do that?


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## Milwaukee (Dec 28, 2007)

SharpBlades;1573149 said:


> My cousin scanned it and it didn't show a code but he agreed that the fuel bowl seal is likely the culprit. I've ordered the o rings.
> 
> I'm thinking that if it acts up again I'll have the driver turn off the truck and cycle the key a couple times to re prime the system then continue. I know it's not ideal, but we are expecting another 12"+ within a couple hours.
> 
> Will I ruin the injectors by having him do that?


What kind scanner he had? Most scanners doesn't work on this powerstroke. Expensive one will find codes. When it pop light it storage codes in.

If I were you I rather FIX fuel leak NOW no matter what. It will ruin injectors when air get inside.


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## FISHERBOY (Aug 13, 2007)

Hav u put an updated cam sensor in it , also maybe change the EXHAUST back pressure sensor, and the tube coming off the exhaust manifold, my 99 shut down over the summer cause of that. If u want to upgrade the IDM box to 120v instead of 110v


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## Antlerart06 (Feb 28, 2011)

SharpBlades;1573149 said:


> My cousin scanned it and it didn't show a code but he agreed that the fuel bowl seal is likely the culprit. I've ordered the o rings.
> 
> I'm thinking that if it acts up again I'll have the driver turn off the truck and cycle the key a couple times to re prime the system then continue. I know it's not ideal, but we are expecting another 12"+ within a couple hours.
> 
> Will I ruin the injectors by having him do that?


I wouldnt drive it till O ring is replace Ford should have it in stock


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## SharpBlades (Sep 13, 2009)

FISHERBOY;1574041 said:


> Hav u put an updated cam sensor in it , also maybe change the EXHAUST back pressure sensor, and the tube coming off the exhaust manifold, my 99 shut down over the summer cause of that. If u want to upgrade the IDM box to 120v instead of 110v


No I haven't. I was reading about how the old cam sensors would fail, so it is on my list of things to check. The only thing I've done to it is an oil and filter/fuel filter change and adding a muffler... Up until a couple weeks ago she's purred like a kitten... Or should I say roared like a lion lol.

As far as sucking air though, if it was shouldn't it be blowing white smoke?

It ran perfectly fine today for the whole route plus end clean outs, about 6 hours.


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## SharpBlades (Sep 13, 2009)

Antlerart06;1574045 said:


> I wouldnt drive it till O ring is replace Ford should have it in stock


You'd think so but I called all the dealers in my area and they don't have the fuel bowl re seal kit, only a replacement drain valve. They didn't even know what I was talking about...


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## SharpBlades (Sep 13, 2009)

Milwaukee;1573255 said:


> What kind scanner he had? Most scanners doesn't work on this powerstroke. Expensive one will find codes. When it pop light it storage codes in.
> 
> If I were you I rather FIX fuel leak NOW no matter what. It will ruin injectors when air get inside.


I don't know what brand or anything, but it was a big scanner... About the size of a laptop. He said that he has used it on powerstrokes and it has always found the code, so I don't know what is going on.


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## Antlerart06 (Feb 28, 2011)

SharpBlades;1574081 said:


> You'd think so but I called all the dealers in my area and they don't have the fuel bowl re seal kit, only a replacement drain valve. They didn't even know what I was talking about...


what goes bad a lot is the drain value
change the filter you get a bowl seal for the cap

So what seal is leaking on yours


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## SharpBlades (Sep 13, 2009)

Antlerart06;1574087 said:


> what goes bad a lot is the drain value
> change the filter you get a bowl seal for the cap
> 
> So what seal is leaking on yours


I know it is one of the o rings on the fuel bowl. But every time I try to find exactly which one, nothing gets wet grrr... I know that it is probably a ring on the drain valve, but I would rather replace all the rings on the bowl. Plus the dealers wanted upwards of $50 for just the drain valve assembly.

I did replace the fuel filter yesterday again, just incase the bowl seal was faulty.


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## Antlerart06 (Feb 28, 2011)

SharpBlades;1574096 said:


> I know it is one of the o rings on the fuel bowl. But every time I try to find exactly which one, nothing gets wet grrr... I know that it is probably a ring on the drain valve, but I would rather replace all the rings on the bowl. Plus the dealers wanted upwards of $50 for just the drain valve assembly.
> 
> I did replace the fuel filter yesterday again, just incase the bowl seal was faulty.


You want watch out some cheap aftermarket filters will leak The ones with cap and filter made together doesnt seal up right

$ 50 is cheaper then buying new injector


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## SharpBlades (Sep 13, 2009)

Well the orings came today, I got them all installed, got the bowl bolted in place, got all the brass fuel line fittings snugged up, and forgot that the friggin FPR fitting is aluminum. thought to myself - " self, you should snug each fitting another 1/10th of a turn, just to be sure"... Snug, snug, snug, SNAP!!!! WTF! 

I don't know whether I am more mad that I have to find a new FPR, or that I can't find the wrench that I threw.


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## Antlerart06 (Feb 28, 2011)

That sucks


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## MickiRig1 (Dec 5, 2003)

I tend to listen to that little voice that tells me not to do something. After 53 years it's been right most of the time!


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## Dstosh (Dec 30, 2003)

Its your cps.


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## SharpBlades (Sep 13, 2009)

Well I got the truck put back together yesterday... The cap for the FPR was $40 at the stealership. I also picked up a new cps and put that on. I have about 75 miles on and so far so good...


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## SharpBlades (Sep 13, 2009)

Well I thought it was fixed, but of course.... It's not. The same thing happened again. I have since ordered a superchips programmer, not really for the tunes, just to read the codes. It should be in tomorrow, so I'll let y'all know what it tells me. I'm really hoping its not an injector


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## fordtruck661 (Feb 26, 2011)

SharpBlades;1586698 said:


> Well I thought it was fixed, but of course.... It's not. The same thing happened again. I have since ordered a superchips programmer, not really for the tunes, just to read the codes. It should be in tomorrow, so I'll let y'all know what it tells me. I'm really hoping its not an injector


Im not one to push people away from this site but I suggest you join this form http://www.ford-trucks.com/forums/forum31/ there are all people that own the same trucks and know just about everything that can go wrong. I am a member and its a great group of guys just like here. Thumbs Up


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## SharpBlades (Sep 13, 2009)

I scanned the truck and 2 codes came up: p1247 turbo boost pressure low and p1316 injector circuit 

From what I've read, the turbo code could mean a stuck waste gate actuator, and the injector circuit could just be a loose connection. I hope that is all it is


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## tyler886 (Mar 8, 2008)

You'll need a good scan tool capable of pulling codes from the IDM. Most homeowners tend to go with AE (AutoEnginuity) as its a pretty good bang for your buck. Performing a cylinder contribution test is almost a must as well a buzz test and KOER selftests. 

P1316 is 99 times out of a 100 a bad UVCH (under valve cover harness for fuel injectors/glow plugs). Especially since your saying the problem is intermittant. P1316 must be fixed first before you can properly diagnose a boost pressure problem. P1316 just relays information to the PCM saying theres a code in the IDM. Most of the time you can get away with just popping off the valve cover and reattaching the UVCH that becomes unseated. Also check for any burnt pins on both sides of the harnesses.

Ford does sell an updated lock for the connector to stay in place correctly. Just be sure the harness itself has no opens in it.

-Tyler


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## dieselss (Jan 3, 2008)

From what I've read, the turbo code could mean a stuck waste gate actuator
only if the tk sounds "windy" or loud while driving.
im gunna say its a hose, or connection.


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## dfd9 (Aug 18, 2010)

Have the injector wiring harnesses been replaced?

They used cheap clips that after time become loose from hot\cold cycles and will wiggle loose. This can be intermittent.

Also, listen to the guys who told you to fix the leak immediately next time.


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## SharpBlades (Sep 13, 2009)

I'm going to be pulling the valve covers this weekend and do the 50 cent mod.


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