01 f 450 7.3 135k miles running real rough and low power like its on 7 cylnders. the ses light is on but i used auto zones reader and it said "pass" no codes found. so do i need a special reader for diesels? any suggestions on what to check to see why its running so rough?

thanks,
JJ

 

sometimes it there are specific codes that these engines will give that can only be read by a code reader that has the Ford specific codes on it. good luck and btw what exactly is the truck doing? sometimes with all the collective knowledge on this site the problem can be diagnosed without the reader.

 

Yes you need a special code reader to check the codes on these trucks. The free scans at the auto parts stored won't work.

Can you describe the rough running better? Does it do it all the time? Any other dash lights or symptoms you can tell us?

 

Like they said on the code readers. How is your oil level and quality? Low oil levels have created lots of problems lately. How about your fuel filter?

 

awhile back it ideled rough at a stop light for a min then went away after i took off. today it got started to move after it had been running earlier in the day and its now constantly ideling and running rough all the time. the ses light came on imidiately when this happened today. it has a major miss and shakes a lil bit. from the lack of power and vibration it feels like one of the cylinders isnt firing. the fuel filter was changed about 10k ago so its due and the oil about 5k ago so its also due. Ive never had a fuel filter clog that fast but who knows. anyways where besides the dealer can i get the ses light code read at, cause this problem looks like its here to stay.

 

I think you are having the under the valve cover 9 pin plastic connector loose problem.. Mine did the same last year.. Poor design on the locking tabs of the connector.. You need to scan the codes .. if it is a P1316, you probably will have to pull the covers and fix the connector.. I used a home shim behind the tabs to keep it locked... been good ever since..(repair cost = $0).. You can also use a digital ohm meter to check resistance at the connector on the top side of the valve cover to verify the problem before pulling covers..
Used the following info:


GGIICIIGG
G = Glow Plug
I = Injector +
C = Injector -
Ohms between the G and block Ground should be 0.1 - 2.0 ohms.
Ohms between the I and C one at a time if one or more is > 5 ohms, it will point to the side's gasket connector or UVC harness being shorted or not making connection.

You can get a ohm meter for less than $20.. good investment.. See My Gallery for pic's of a loose connector and home made repair shim...

 

What city in Ca.. maybe some here is close by that has the proper scanner..

 

im in sacramento

 

Maybe you could start a new post... asking for scanner help in Sacramento
I think the key to solving the problem is reading the codes.. My Diablo Sport programmer will read most of the codes for our engines,but you are abit too far away !

 

ok since we dont have time to let the truck sit while we figure this prob out it went to the diesel shop. they said there is a missfire in cylinder #7 could be an injector. also it might be the wire harness connector under the valve cover that "clintbonnie" was talking about. they said about %70 of the 7.3s they work on have that problem. anyways they will should have it done by tomarrow.

 

Too bad we didn't have time to really help ya... I know you have to keep those wheels rolling. Let us know what the real problem was..later.

 

dammit it was that harness! $300 but its back on the road today.

 

Was it shorted, disconnected at the connector or do you know? Did they do both sides? Just curious

 

they said it came apart from the heat. they fix the retaining clips so it wont happen again . i assume just one side unless they didnt tell me.

 

Exactly what happened to mine..the connector separated on the driver side under the valve cover.. The plastic locking tabs just warp from the heat..(ford fixed the problem sometime in 2003). When you have time and if you want to save some money, suggest removing the other valve cover (if they just did the one), to fix it from happening again.. Both of mine were separated, but the pass side was still working bearly.. I only had 65K miles on the engine. You just need a shim behind the tabs.. One guy modified a quarter coin and slipped it in.. You can reuse the valve cover gaskets.. so the repair costs are 0.