starting problems, air in fuel line?

[sdfabrwannab]

My truck was getting progressively worse. Starting with just running rough when it started, to starting and then dying and when trying to restart is seemed like the truck ran out of fuel. Then it got worse and started stumbling and dying when I was driving. I bought the kit that replaces the plastic caps, fuel lines and o rings for the injectors. Well I was still having problems. I took it up to a ford dealership where a friend is their ford diesel mechanic, this was a few months after I replaced the o ring, caps and fuel line. I cant remember off the top of my head but I know he replaced a couple of the o rings. I am still having starting problems. It will crank and fire, then die and when trying to restart it acts like it ran out of fuel, when it does fire it runs rough and smokes. I would take my truck back up to him but do not want to pay another bill. Where would you guys start and how do I go about getting my truck to start like it should again. Any help would be appreciated.

 

[snowman89]

I would check to see if your lift pump is still working. If it is then check the timing of the injection pump.

 

[jtate]

+if you let it sit all night and the next morning unscrew the filter and see how much fuel is in the filter.

 

[sdfabrwannab]

OK I dont know if it changes anything. Its cold out here so I had my truck plugged in, and in the past ive noticed that when I plug it in it doesnt stumble or anything when I plug it in. When plugged in it fires up and idles rough for a second with some white smoke and then idles fine. Unlike when its not plugged in and fires and dies, not just when its cold outside either. Any suggestions?

 

[jtate]

run the truck let it sit over night then in the morning unscrew the fuel filter off and see how much fuel is in the filter, this is determining if you still have a possible air leak. if the truck is starting fine with the block heater plugged in and not so great with it not plugged in relying souly on the gps then it sounds like you have a couple possibly bad glow plugs. how long does your WTS light stay on for ? i had 2 simular issues with both my trucks. the 85 would start for a sec and then die , you would have to cycle the plugs a couple of times and it would come roaring to life. turned out to be a couple of dead glow plugs. now on 91 model after replacing return line caps and orings , i was having a intermitten starting issue just like you explained and it was caused by the olive o rings on the fuel filter and ip hard line connections .

 

[sdfabrwannab]

so if it is an air leak problem how full should the fuel filter be in the morning when I pull it off?

 

[jtate]

most of the time mine wouls show about 1/2 full. how long does your wait-to-start light stay on?

 

[sdfabrwannab]

I will check the wait to start light next time I go out there and its cold

 

[jtate]

when its warmer outside does it still start hard? ive learned on these trucks that the idi's rely on the gp's alot.

 

[sdfabrwannab]

Yes it starts hard when its warmer out, and just a couple months ago I had a couple glow plugs replaced so they were all working then. That was when I had the truck in the shop for the fuel problem, and when I got it back it was still starting hard like the running out of fuel thing.

 

[jtate]

im just trying to rule out the gp's as a posible culprit. these engines rely soo much on the gp's when its cold or hot temps outside, more so in the cooler temps. my 85 it can be 70+* outside on a cold motor and if you dont use the gp's too start it, it will spin forever before it starts if it starts. now if i manually use the gp's after about 6sec on the buton it will fire on about 1/2 a turn. im not trying to say that it couldnt be air intrusion in the system but with the temps that everybody is seeing even with a healthy fuel system the motor is dependant on the gp's, so why not rule them out and get that out of the way especialy if its starting easier with it plugged in. i know you say you just had some replaced two months ago but that doesnt me zilch to me. i burnt a set up in 5 days lol. i had repeated gp issues for a whole two weeks untill i replaced them as a set and theyve been in it for 2yrs now with no issues.

 

[sdfabrwannab]

I understand totally, when I start the truck in the morning I will see about how long the wait to start light comes on and let you know. I do appreciate the help.

 

[jtate]

just before you starts it up dont forget to unscrew the fuel filter and tell us how much fuel is in it lol.

 

[Agnem]

When you unscrew your fuel filter, fuel should spill out all over the place. If it doesn't do that, then it has air in it. So technically, you don't even have to take it off all the way. Once you break the seal, fuel should flood the top of it. Taking it off the rest of the way, and looking down in the filter will only tell you how bad the leak is. It won't really reveal anything usefull, other than perhaps knowing about how long you would have to crank it to get it to fill back up. When you keep your engine plugged in over night, it won't get as cold as it might otherwise, and this can reduce the severity of the leak. If you left it plugged in for several days, you would still have the same start and quite then crank awhile you would have without plugging it in. The extra heat is just extending the time it takes the filter to drain off. Any time you suspect your filter is not full, you should actuate the schrader valve to let the air out and get that filter full as fast as possible, particularly if you still have the stock mechanical lift pump. Speaking of the schrader... always keep it capped. The cap forms a redundant seal and adds another layer of air leak protection. Read my thoughts on hard starts and air if you haven't done it yet.

 

[Popeye2347]

Speaking of the schrader... always keep it capped. The cap forms a redundant seal and adds another layer of air leak protection.

I had not thought about a cap there, but it makes perfect sense, but better if it is a metal cap with an internal gasket. Good call.

BTW Agnem, you link on 'Thoughts' I find inoperative.