Well, about 2 months ago my truck just didn't want to start anymore. Drained the battery and burned up the starter. Replaced starter and charged battery, decided it was a fuel problem. Replaced the fuel filter, air filter and fuel lift pump because it was easy and relatively cheap, no change. Just last week replaced the injector pump, all new injectors and new glow plugs. Incidentally the WTS light had not been coming on for some time so when I checked the GPs all were bad (Autolites) except one. Now I have 8 new Motorcrafts and the WTS light and GP cycling are working great. Now, back to the problem at hand. I have in the past replaced all the return hoses and now with the new injectors all new o-rings and there are no leaks present. My IP was leaking before but now there is no diesel smell at all. I have read the posts about the fuel shutoff solenoid getting hot when it is new and sticking, so just tried pouring water on it and that didn't help. The fuel solenoid seems to be working great clearly clicks on and off. The starting problem is terribly intermittent works great sometimes and won't start other times. Once its running it runs great. The only thing I can think of is maybe IP timing? But, it seems like that would affect running also. Currently it is just set to the static timing mark.

So, if anyone has any other ideas before I break down and take it in somewhere I would appreciate your thoughts. I will be out of town for the weekend but will check back on Sunday night.

Thanks for all previous and future help on this. Because of your helpful advice the IP replacement went very smooth.

 

Hand in there Gary,

I just let my 91 sit for two weeks and sure enough it got air somehow into the fuel filter and was difficult to start. I got air when I checked at the schraeder valve. I have done all the return fittings, o-rings, etc.. just recently.

My guess would be you still got an air leak. Check for air at the Schraeder Valve next time you have starting problems to confirm this.

As for my 91 I am going to upgrade my fuel filter set-up to a Racor set-up like I did on my 93, I just have not got around to it yet. A lot of those fittings around my factory fuel filter look suspicious to me and the drain line looks like it has the ever so slightest weep on it.

Seb.......

 

My 89 had problems starting when it got hot...air leak of some sort...I have the IP in my 84 now, had simular problems but not as bad...installed "push button" for the plugs, works like magic?!!

 

Define intermitant starting problem,is it always a cold start,is it always a hot start?Are the conditions always the same,such as parked up hill or down hill.These may sound like stupid questions but every condition has a diff prob ascoiated with it.

 

As I said I have not had any trouble for months because I drove the truck every day. Then the other day I had to park it on a steep uphill with the rear tank in use which was down to 1/4 tank at the time.

I think the incline together with the low rear tank level may have provided enough gravity suction (more than usual) to pull air in somewhere where it normally does not pull in. The truck a crew cab so on a steep incline there would have been several feet of additional suction head between the rear tank and the top of the fuel filter.

I have not had any problems since I started driving the truck again daily. I know it is air getting in because I had to bleed the filter at the schraeder valve to get the truck going again.

On possilble thought I had was that the rear tank was replaced by the last owner (rusted out) with a new tank and the rear tank gauge always reads high. So 1/4 tank is probably getting a little low maybe to the point were the fuel return tubing is no longer properly submerged when the truck is parked on a steep incline.

I am still going to upgrade to a racor fuel filter set-up which will eliminate all those potential air leak connection around the existing factory filter. Also 2 micron filtration is much better than those factory 10 micron filters.
Lastly, given my 91 is 15 years old I will have to start looking at all the fuel connections between the engine and the tanks. There are a lot of connections and any one of them could cause the air leaks.

 

Thanks to all for your suggestions. Since I posted this it has not failed to start, it has started great every time. By intermittent I mean it sometimes does it when its hot and sometimes when its cold, it doesn't seem to matter. It is typically parked on a flat surface. I have searched again for leaks but still not found any. If it happens again I will check the shrader valve for air.