1986 F250 with 6.9l diesel. It is really hard to start, even with new glow plugs. It apparently does not matter how often you cycle the glow plugs, it is still difficult to start to the point of feeling like you are running the starter too long. There is an after market electrical before the mechanical fuel pump that comes on with the key. When it finally starts, there is a lot of white (fuel) smoke that takes any where from 5 to 10 minutes to clear out. Other than that it runs fine and just passed Colorado emissions test.

 

Sounds like your mechanical pump is shot.

I see no reason to have an electrical one before it other than the PO tried to "afro engineer" it and did not want to spend the money on a new mechanical pump.

IMO: when all else fails put it back to the way it's supposed to be and fix it right.

 

Check out the pre powerstroke forum here. But the glow plug controler sounds like it is bad. It screws into the back of the block behind the intake. Do yourself a favor and upgrade to the solid state GP system off of a 7.3

 

Have the little lines between the injectors ever been replaced? If not, get a kit and replace them and the little o-rings in the middle of the plastic injector caps. You will have to pull the metal injector lines off to replace them. If the o-rings are old, then they will leak air and let all the fuel run away from the injection system back to the tank, making it hard to start, even in warm weather.

Also if you fell into the trap and bought Autolite or any other brand glowplugs, then they are probably already burnt out. You have to buy Motorcraft or International, which are both made by Beru. Any other glowplug will burn out, and you run the risk of the glowplug tip swelling up and breaking off into the engine. If you did get the cheap plugs, check them and I bet some of them are already burnt out-I hope you can get them out without ruining the engine.

 

I did not like the electrical fuel pump myself, especially since it ran all the time as soon as the key was turned on. So I removed the electrical pump and installed a new mechanical fuel pump. It is even harder to start now. Prior to my purchase a mechanic installed new, ac delco, glow plugs. But I am now wondering if it is a glow plug issue since when the engine is warm there is absolutely no problem starting. Someone mentioned the glow plug relay, but the light does come on for a while, though it does not seem to make any difference as to how many times you cycle the glow plugs. Is there a way to test the relay & glow plugs?

 

The glow plugs were ac delco and installed by a mechanic prior to my purchase of the vehicle. I wonder about the relay since I removed the electrical fuel pump, installed a new mechanical fuel pump and it appears even harder to start now. The glow plug light comes on but it does not appear to have any affect for starting. Is there a way to test the relay and glow plugs in place?

 

A very simple test is to take the connector off the glow plug. then take a test light and clip the clip to the + battery term. Then touch the glow plug(where the connector goes. The test light should light. If not they are bad. Go to each glow plug. There is a resistance test but this will tell you if any are completly burned out

 

Quick question, stosh: what is IMO? I've seen it several times and don't know what it means. I know, I know off topic. And boosstuff- listen to Dave, use only Beru plugs. You can find them online for $9.99 each. Go to DieselFiltersOnline.com, under 6.9L Ford.

 

IMO = In My Opinion

 

Thanks, Brad. By the way, wouldn't you think that a mechanic would know better than to put ac delco plugs in? On a Ford, one would think that he might at least went to an autolite. Delcos are pretty much good in GM's only, at least IMO. Way to sound cool, eh?

 

It really sounds like air in the lines to me. My truck would start ok if I started it every day, but if it went for more than a day it would take awhile to get going. After I replaced the return lines, I can let my truck sit all week and it will start right up. Seems most people add the electric pump to fill the lines before starting. It's a band-aid fix though. Since your truck got harder to start when you removed it, that makes me think you have a leak.

 

Delco products are a very good product. Their electronics are excellent. I am sure they are better than the crapy autolites,


And as Syco said. It does sound like air in the fuel system. But the test light trick is free and only takes 5 min. if you decide to do O-rings and caps...here is a link where i got mine http://o-f-i.com/search.php

 

I appreciate all your input. An update. I honestly do not know if ac/delco is better or worse than autolight. I don't even want to think about original ford equipment, but who knows. This morning, it was pretty warm here at about 48 degrees. I went out to start the truck, did not wait for the glow plug light to go out, just hit the starter and it started quicker than a couple of days ago waiting for the glow plug light. There are new hoses between the injectors, so I for now have to assume they would be smart enough to do the orings. I am not thrilled with the prospect of just replacing parts to make things work and would like a reason. If it were air in the system, which could be possible, I would wonder if the heavy fuel/white smoke would be so prevelent when if finally started?? Boosstuff

 

Last evening I went out to start the diesel, at which time I had a terrible time. It had set for a couple of days and gave me fits. I have not had time to do the test you all recommended, but I hope to have some time this weekend to follow up. When I tried to start it last night, the glow plug light did not even come on until I had cranked it for a while. I work part time in a parts store, so can generally get parts for less than most people. I really need to figure out why this beast is so difficult to start. Any test or recommendations are appreciated.

 

sounds like air in the lines. But you should be able to hear the GP relay clicking , if it is working