I bought a 1986 (MY FAV. YEAR FORD)f250 6.9 diesel with 119k on the odom. that was sitting for about 4 years and used very seldom. Dusted her off, changed oil, PASSED imission test 100% and took a trip to Flagstaff from Phoenix.
On the way up the hill the temp gauge went from middle norm to low norm and she started smokin and sounded like a cold winter start up in upstate NY. Ran ran like crap all weekend till I came back down the hill into 100 degree weather and is still not warming up completely.

I am ready to replace the Tstat but the place I think it might be does not look familiar and I have not yet got my hands on a shop manual.
Would like some advise before I take off the Alt. and air pump to find no tstat below the top water hose fitting.

Thanks AlanT

 

The thermostat is located on the upper hose housing, you have to remove the alternator and vacuum pump to get to it, make sure that you use a factory type thermostat. Many aftermaket thermostats will not tolerate the vibration a diesel causes.

As for the miss, you need to check all cyl compression, it sounds like your injector pump may have gone bad. You can check compression usings a regular auto type compression tester, remove the glow plug and you will have to make an adapter to fit the compression guage. The compression guage only goes up to 300 psi, if you have that much the cyl is fine. Check all 8. If it is not compression the only other thing is the injector pump.

Let us know

Dave

http://a2ztowing.homestead.com/a2ztowing.html

 

Thanks Dave,
I did pull off the hose and peek inside to see the stat.
I dont recall mentioning a miss. The rig runs great When it's warm but I have a small fuel leak at the pump till it warms up. I think it is coming from the fiting where the fuel feed goes into the pump.I tried tightening it once and thought it stopped but still get a small drip on the exaust till it warms up. Any sugestions?

Thanks again.......Alan

 

Sorry about the miss, must have confused with other post, anyhow, on this line there is a special oring seal that needs to be replaced. Go to ford and get two, one for the line coming out of fuel filter and the one at the injector pump. Very simple to replace. Place a drip pan under the rear part of the engine, as you will loose some fuel when you take this line off, there is a drain area on the valley pan that goes to the back of the motor. Good luck

Dave

http://a2ztowing.homestead.com/a2ztowing.html

 

Thanks Dave1
I am so happy to have found this forum.

 

I went to Ford today to get the o rings and the goof at the parts counter tells me that I cannot get the rings seperate from the $56.00 fuel line.
Is there a part number I could use to order them?

Thanks....Alan

 

The seals for the fuel line are available through ford by them selfs. Anther though would be to go to an international dealer. They are better at finding parts for these trucks. If you dont have that option, I can get the parts number from ford but it will not be till monday. Please let me know.

Dave

http://a2ztowing.homestead.com/a2ztowing.html

 

Will have to find a Int.Dealer in Phoenix I'm sure there is one.
Further inspection after cleaning the engine reveiled that the fuel leak seems to be coming from the excelerator pump at the bottom of the injection pump (if that's what that is)Can it be rebuilt or should I hold off till I can afford the $300 for a rebuilt pump? It leaks untill it's warmed up. And also where is a good source for a shop manual for the 6.9?

Thanks again......AlanT

 

I have never played with the injector pumps, It is our shop policy to replace the pump. Other than turning the fuel up or timing we replace pumps. As for a good shop manuel, haynes makes a very good diesle manuel available at most chain autoparts stores.

Also popular mechanics makes cds for the truck which use the Al Data info. I have several and most of them are very good. Many diagrams and tech recall info. Cost is 19.95 for each model. You can buy the CD and register the vehicle you have. Additional registered vehicles are 14.95. Good sorce for info.

Dave

http://a2ztowing.homestead.com/a2ztowing.html