OK I don't know if this is the proper place to post this or not, I apologize if it's a bit out of context, but since the 1st gen cummins motors use the rotary style pump as do the 6.9L Ferd's I decided I'd try here.

Basically, my 87 F-250 runs great, except when you let it sit, then it just turns over and over and never fires. Starting fluid usually gets a sputter out of it( I know that's bad, but some days a little bit is necesarry) but ussually I bleed the fuel out of it while hot crossing the starter relay to get it to spin and she fires up, runs all day fine, never misses a beat, then bam again it does it. Does this sound like a pump problem? I'm getting ready to just replace all the lines from the tank to the lift pump(which I've put a brand new LP on it and no change) I've changed the fuel filter, glow plugs, the gp relay's workin, I haven't seen any fuel leaks at all, but I'm not sure if it could be running back into the tank or not. Is there a check valve in the pump? I asked the guys at napa if they had an inline fuel filter with a check valve in it that I could add but they were worthless, they looked in their catalog for like 2 seconds before telling me no. I've seen alot of CTD owners here with similar trucks so hopefully someone knows a cheap trick. At $350 bucks for an IP it's not so bad, but still I'd rather spend that on new exhaust or something for the CTD, this is just my beater truck, don't need another addiction lol. Theres some light smoke at WOT at higher RPMS but other than that she runs pretty clean unless it's set for a week or so, so I imagine the valve seals are in need of replacing after 250k hard miles. But could it be a symptom as well?

 

the old 6.9 were a son of a gun to start when the glow plugs weren't working , I would pull all the glow plugs and check them and make sure the controller is working. it is mounted behind the air filter on the engine.

 

I don't know much about that truck but I know who to ask. Three good ways for you to get help: PM Argve on this site, visit The DieselStop.com, and/or visit Oilburners.net. Argve is Ford IDI guru who came over to the "dark side" (Ford Vader?), and both those sites have very active IDI forums with knowledgable members who can answer your question. Good luck.

 

Sounds like is getting in the system to me. My GPs are out on mine. I have the relay disoconnected and use ether. It only takes a small wiff and it fires right up.

Have you ever replaced the small fuel return lines between the injectors, o-rings under the plastic T's that sit on top of the injctors or the cross-over hose at the rear of the engine?

I had to replace all of those when I installed new headgaskets. The little ones that go between the injectors snapped like a carrot. Hard as a rock.

IIRC, there are square o-rings at the fuel line connections on the fuel heater at the front of the engine. They could be bad also.

Are the fittings at the fuel supply pump tight?

FWIW, the fuel injection pump on a pre- '94 Ram is a Bosch VE pump. The 6.9/7.3 IDI uses a Stanadyne pump, IIRC. From what I hear, they are usually at around 100k miles. They are only lubed.cooled by the fuel, same as a VP-44.

 

I don't think it's the glow plugs, I replaced all of them, and the relay was working, sometimes it'll start and run for about 10-20 seconds then die, and then have the same problem, which makes me think it's air in the lines. The little bleeder valve above the fuel filter, if you crank it over and hold that open it spits and sputters air, so I'm guessing that's what it is. I'll have to go take a look at those return lines b/t the inj though, I haven't seen them leaking, but I wasn't really paying attention to them either. Are they high pressure? I've got to go unstick the hood first, it wouldn't open yesterday when I went to try to work on it, stupid Ferds lol. No really it's been great to me, just this one thing and the hood sticking :-P Thanks guys I appriciate it.

 

Years ago I had a 85 ford 6.9. Ran fine when it ran. I agree with two previous points. The 6.9 just does not start without plugs. (Ether may be the exception)

I also had to replace the injection pump at around 90K. But when it went, IT REALLY WENT. I went from rougher than usual starts to NO GO in about a week.

Glow plugs are a fine idea, just not the way they do it on the 6.9. I had a 5 cylinder mercedes with plugs and NEVER had any problems. Started down to 20 below, could double and triple cycle the plugs without worry.

Ford decided to be clever. They installed 6V plugs with a 12V system. I had to replace a cooked set every year. I replaced the entire wiring harness, the relay, the very spendy little "brain" at the back of the motor and nothing helped. The idea is the 6V plugs heat up really fast and the "brain" says when to stop by measuring resistance so the plugs don't cook. Never quite worked that way.

P.S. Other thing I just remembered. Truck had double batteries. Had one go bad, and when engine cold the one battery just didn't spin the motor fast enough to make her pop. It happened slowly so I didn't notice until had problems with every start. Two new batteries, solved that one.

Moral of the story .. . I found a cummins. . . .sold the Ford.

 

Not high pressure. Just small spring loaded clamps holding them on. Be careful pulling the little lines off. The Ts could be a little brittle. Never broke any of mine though.

 

lol I originally bought the dodge for the motor to go into the ford. But that never happened, and I've done too much work now to switch over, so eventually there may be a swap if I find another 5.9L. But for now I've got the ol 6.9L. good motor,,, when it starts,,lol,,,,drove one with a turbo kit on it,,,pretty strong, nowhere near my CTD but good enough for a daily driver i suppose. Maybe that old hx35 could be turned into something ??? For another day, lets get it started first cuz Diesel is .50 cents cheaper than gas here!!!!! and the dodge still isn't near finished,,,:-/

 

Hey, this is a Cummins site
Oh well, I use to work at a Ford truck dealer. Some of the earlier Diesels had a fuel water seperator on the firewall on the drivers side. I saw many of them start sucking air and would cause you to lose prime. I bypassed many of them, there is also a lift pump on the right front of the engine. Make sure it is working. I have also seen trucks with 2 tanks have problems with the switch over valve.
What I would do is get a bucket of clean fuel and put a fuel line right to the fuel transfer pump. that would eliminate both tanks, switchover valve and water seperator. If the truck runs good off of the bucket then your problem is before the transfer pump. if it still wont run than problem is from the pump forward. That is a start anyway. Good luck

 

Did ya get her rattl'n yet?

As posted previously you have an air leak somewhere which is allowing the fuel to drain back into the tank. Most common areas have been mentioned (fuel return line system = o-rings under caps and water sep on firewall). I would start looking at those areas.

A complete return line kit is like 25 bucks at most diesel shops.

Most guys end up bypassing the stock water sep on the firewall and getting an all in one unit for direct replacement at the stock OEM fuel filter location next to the alt. From what I have heard they are a spin on deal from various suppliers Diesel Injection Service for example. The later IDI powered trucks came with the type of setup found within the link I posted so you could if you wanted to run down the local bone yard and pick up the filter head and bowl (the thread size/pitch is different on the OEM 7.3 style - it's larger than the stock OEM 6.9 filter) But all other fittings are the same and in the same location. Now I will tell ya that I dropped the bowl off mine because it was a pain in the rear bumper to deal with and just started picking up a one piece filter/sep from napa part number is I can't remember but I can look it up for ya if need be - I would have to pull out my log book on The Enterprise and go digging... So if your interested in the part number drop me a PM and I'll go digging.