Hello, I am new here and in need of help. So here it goes,Sorry it is so long I am just trying to give all info I can think of to make it easier for some one to help. I have a 84 Ford F250 6.9L IDI that I have owned for the past 5-6 years. My dad owned it before me for about 4 years and used it for his tranny shop to do parts runs and tow every once in a while. He never had any issues starting it even it the winter it would sit for days sometimes even weeks and he could go out and hold the gp on for 10 or 12 sec and it would fire right up. So a little more info, it has a monetary toggle to run the gp and was set up that way when he bought it and it always worked flawlessly. I bought it from him and it had ran and started first try every time holding gp for 10-12 sec in winter and in summer didnt even need to use the gp up untill about a year 1/2 ago. It was fine in the summer but winter hit and it started to take a little more cranking to get it to start, the later into the winter it got the longer and longer it would take. I asked my dad if he had ever replaced the gps and he hadnt so I thought that was probably it replaced all 8 with ac delco (that was what was in it so i just went with that not knowing what was best) and when removing the old ones they didnt look burnt or bad but replaced them anyway. The first time after new gp fired right up after 10 sec of gp on, drove it to work 15 min drive on highway, when I go to start it after work 11 hour shift about 4pm 30 degrees F outside it wouldnt start had to tow it home. It was cranking a little slow so I had batteries tested and they were both bad, got two new bat and droped them in but it still took it a few times cranking to start it. Once started and warmed up it will start fine the rest of the day as long as it doesnt sit for more that 3 hours any longer than that and it takes alot of cranking. I have replaced the fuel lift pump and gp relay as well. It is summer now and it still takes alot of cranking to get it started, I have replaced the gp twice after the first time as the ac delcos burned out so I tried autolite (not knowing they are crap as I have read every where looking for a solution) and they burned out after one 10 sec use so I got BERU/MOTORCRAFT gp and put them in which was just two months ago and they stopped working after about 1 week. I am at a loss of what the problem is with the gp burning out and am not sure if that is the only prob or if that is just part of it. Why would the gp burn out so quick? The longest I ever hold them on for is 12 sec which never was a problem before, and also it has a very hard time starting now even in 90 degree F weather as to when I first got the truck 5 years ago I didnt even need gp in the summer? Any help would be great, this is my first diesel and I have no clue where to start looking for a solution. Thanks in advance.

 

7.3 IDI 1990 here, it sounds like your controller replaced and the glow plugs go with Beru, or if you want to find the 7.3 idi glow plugs and use them you can go to 30 sec on the 7.3 idi ones, insted of the spade terminal you would have to soldor on the round type, the reason why I said the controller rweplcement, is insted of the 6.9 controller, you can put a heavy duty solenoid on it and some good heavy wire, But it's all upto you friend. How mant miles are on her?

 

Hi, thank you for your suggestion. The only thing is that the controller is not even connected as it has been unplugged and a push button was installed to manually run the glow plugs. The last set of glow plugs i put in were motorcraft and i never have them on for more than 12 sec, it has worked fine that way for the past 9 or more years and just recently started burning up plugs and very hard to start. It has 153,000 miles on it, i just got some new motorcraft glow plugs today and put them in and it fired right up like always when its got new plugs in it. I am just thinking that these will burn up like the last 3 sets have in very short time. Any other thoughts or ideas would be great and i will look into c ost of converting to the other style of glow plugs, I'm just not able to spend any money at the moment as i am on a two week layoff right now but really need to figure this out before winter as this is my daily driver to work. Thank you again for your reply.

 

Mine has 95,118 and it starts everytime, Other than the pesky glow plug controller only staying on for 8 sec it starts right up.

 

I haven't used glow plugs in my 6.9 diesel for atleast 10 years.

Best thing I did is put in a eather injector system like from a farm tractor and inject it before the air filter. And rememeber it doesn't take more then a quick squirt. YOU CAN"T HAVE ANY GLOW PLUGS HOOKED UP IF YOU TRY EATHER, BAD THINGS WILL HAPPEN.

 

Thank you Hummin Cummins for your reply. I have read about many horror stories from using either in my search for an answer to my problem and many people say not to use it ever and others such as yourself have said that's all they have used for many years with no problems (without using glow plugs of course). I used either once last winter when all of my gp where fried and i was trying to leave work. When i started having all of these problems with starting i decided to carry some with me just as backup, but if this new set of plugs burns out on me again I may just go with the either injection as that would be a much cheaper route than constantly replacing gp and other parts trying to figure this out. I have read though that over time either will ruin the motor? As with anything though there is always as many people who say it will as there is that say it won't. Thank you for your input.

 

You may want to test your push button switch. Make sure its not supplying power when its released. Even a small amount of power (2 or 3 volts) coming through the button will cause them to burn up. As for the getting harder to start in warm weather usually when a diesel engine starts loosing compression (one weak cylinder will even cause it) the first place you will see it is on the cranking time. Its not able to compress the full enough to get it hot enough to ignite. Also this new sh*t they call diesel isn't worth a crap. One of the test Chevrolet has you do with diesel to make sure its not contaminated with gas is to pore a small amount on the floor and try to light it with a lighter. If it lights it has gas in it. So This new fuel is so crappy it wont even light unless it is extremely hot.

 

Thank you dukes-78. I will have to check the push button that its something i have not looked at, i know everything i have read everyone says the diesel now is crap, I try to use additive for lubricity and to help with cold starts all year around because of that but i know there is only so much it can do with such sh***y fuel. I use the Power Service additive in the white bottle because it is recommended on almost every forum i have looked. As far as the compression how would you test that and if there is a loss would it be a matter of replacing piston rings to fix that? Thank you again for your reply and knowledge it has given me some new things to consider especially because i think there is more to the hard starts then just the gp being fried because it used to start first time just bumping the key in the summer even in a40 degree F day and now it has to have glow plugs used (when there not fried ) or crank for 3-4 min even on a 95° day. Thanks again.

 

You will have to get a compression tester that will screw into the injector holes or you can do it in the glowplug holes. As for the minimum compression on a cylinder or how much difference you can have between cylinders you will have to look up the specks for your year model. As for fuel additive I found a place that carries Stanadyne diesel additive. The first thing I did was change my fuel filter and filled the filter with the additive and that will flush your fuel system and clean the injectors. Then I add a 12 oz bottle to about every other tank full. The additive isnt that expensive and It seems to be helping. I trust the Stanadyne additive as Stanadyne is the manufacture of the Injectors and Injector pump that came factory in my 94 7.3. Dont feel bad Im in the same boat mine has 287,000 mi and is due for a rebuild, but there worth it. With only 153,000 if you find that you have only one weak cylinder you may be able to change the rings on that one cylinder you will just have to check what kind of condition the cylinder is in.

 

Another factor is, how good your starter and batteries are. My 6.9 got to where it was starting harder. Didn't really notice but the starter was cranking slower. I don't remember the exact number but the amps it was requiring was way out of spec. Rebuilt the starter and the differance was unbelievable.