Running Rough Today, Whats Broke?

[02x72]

Driving the truck truck today it started to run horrible all of a sudden. I stopped to get fuel at a place I regularly go and a few blocks later it started running like its on 5 cylinders. First and second gear are horrible, and it clears up a bit once I get into third, but its still noticeably bad. Fuel filter is fine, I drained it and practically no water came out thats not it. Im thinking an injection pump considering Ive been getting progressively worse fuel mileage for the last few months and as far as I know its the original one. Do those just go out like that though, I thought it was a gradual thing? And now that its off it wont start again so its diagnosing anything is gonna be fun.

 

[gatorman21218]

ok so there was no water in the fuel but could it have clogged the filter? having it die just after filling up I'd be very suspicious of the fuel.

Tell us more about the no start. does it matter if its hot/cold? does white smoke come out of the exhaust when cranking? is there fuel pressure at the schrader valve when cranking?

 

[02x72]

Fuel filter is fine, tried to start it as soon as I shut it off when I got home and had no luck. Lift pump is fine, theres plenty of pressure at the filter. I thought about bad fuel as well, but I get fuel from this place all the time and its a pretty busy station, so I find it had to believe thats the issue. Its smoking white a considerable amount when it was running.

 

[icanfixall]

Ok we need more information.. Just a ruff guess on the miles on the engine or the injection pump. The white smoke has me wondering whats going on. Your telling us it smokes white when its running and the mileage has been steadly dropping. Then it felt like it was running on 5 cylinders... That sounds like a head hasket let go between cylinders and water was getting in the cylinders for a while. Did your coolant level drop and does the enfine crank but not start. If it wont crank then a cylinder has filled with coolant... So there are some questions to answer before morehelp can be given..

 

[HammerDown]

With the above being said...pull all glow-plugs out, see if it cranks and pushes water out a GP hole.

 

[redneckaggie]

how do you know the filter is good. drain some fuel into a bucket and see if it smells like gas. what you are describing sounds like contaminated fuel or a plugged filter. does the smoke from the exhaust burn your eyes like diesel.

 

[hesutton]

Those cylinders are missing because they are NOT getting fuel or they have lost compression.

Lack of fuel:
Bad fuel (even busy stations can get a new driver who emptys the wrong stuff into the wrong storage tank)
Clogged filter, lack of water doesn't ensure a good flowing filter. How many miles are on it?
Poor supply of fuel, something is hindering flow from the tanks. The lift pump is crapping out. Junk in the lines. What's your fuel pressure?
Bad IP or injectors. Not your typical failure, but it could happen where it won't feed certain cylinders. Leaking/stuck injectors from age, wear, or trash in them.

Loss of compression:
Bad head gasket.
Bad valve/guide wear (or some other issue in the valve train) preventing the valve from opening or seating properly.
Cavitation
Piston/ring damage or severe wear.

Those are just a few possibilities. Gotta test a few things that have been posted by others and report back.

Heath

 

[058hammer]

First step in trouble shooting a diesel engine big or small is change the filter.

 

[02x72]

I pulled the filter, its clean. Poured out what was in there and and seeming perfectly fine diesel came out. Fuel pressure is fine, schrader valve shoots it across the engine bay when cranked over. Coolant level is fine, and when i smelled the smoke before turning it off it diddnt smell like coolant, like a fuel smell. Engine cranks over like a champ, just wont fire. The IP and injectors have factory gray paint on them, and I dont know if they have ever been changed, so as far as I know they have 225k miles on them. Until the last month the truck ran perfect, around 18 mpg and pulled my chevelle through the mountains like a champ. Then the mileage started to drop, it wouldnt get up to temp as much, staying around 160( yes I replaced the tstat) and now this.

 

[redneckaggie]

15u(micron) is less than 5 TEN THOUSANDTHS. that is .0005 inches, most people have never even dreamed of measuring that small, much less seing something that small, also coming from the man that builds these pumps, never dump fuel out of a filter because what you have just done is allow unfiltered fuel into the injection pump side of the filter. How expensive is a filter, much cheaper than an ip which is what you were preparing to replace in the first place. As a reminder please make sure to keep troubleshooting scientific, plenty of pressure does not tell me anything, 5 psi is scientific. I didnt see anything in the fuel that I dumped out means nothing unless you were using a microscope. I have had plugged up filters that poured out perfectly fine diesel until I beat the crud out of them.

 

[058hammer]

15u(micron) is less than 5 TEN THOUSANDTHS. that is .0005 inches, most people have never even dreamed of measuring that small, much less seing something that small, also coming from the man that builds these pumps, never dump fuel out of a filter because what you have just done is allow unfiltered fuel into the injection pump side of the filter. How expensive is a filter, much cheaper than an ip which is what you were preparing to replace in the first place. As a reminder please make sure to keep troubleshooting scientific, plenty of pressure does not tell me anything, 5 psi is scientific. I didnt see anything in the fuel that I dumped out means nothing unless you were using a microscope. I have had plugged up filters that poured out perfectly fine diesel until I beat the crud out of them.

What he said.

 

[HammerDown]

OP...did you crack the injector lines to make sure when cranking, fuel is being pushed from the IP?
Also what about the shut-off ontop of the IP, are you getting a strong 'CLICK' when turning on the key? if it's not opening, no fuel is interning.

 

[icanfixall]

Well after rereading all this a second time its my feeling that you pump has failed. From your own posting. It was running well. Then fuel mileage began to drop. Now its not running. This tells me something was failing slowly but now its completely failed. The low mileage was a warning.. Also knowing the injecters are probably the original ones tells me they are twice the mileage they usually last... So I feel safe telling you its time for a rebuilt pump and a NEW set of BB code injecters. Also have the engine timed once any of this wirk is done

 

[redneckaggie]

even if he needs a new ip a fresh fuel filter should be installed with that also. easiest way to tell whether ip is shot is to crack injection lines and see if they are getting fuel. I have never seen a pump that just flat quit. will not say it isnt possible just extremely rare. The only pump failures I have seen where leaks, sticky advance mechanisms, dead fss, simple things. This is through over 20 trucks I have worked and tinkered with. One of them had over 350,000 on the stock ip and injectors. the only thing that had been done to the ip was a reseal of the top cover.

 

[02x72]

FSS solenoid is working, there seems to be fuel getting to the lines, but there is no way of telling if the pump is pushing 1800 psi to fire them. its not a fuel filter issue. I have an inline glass filter before the main filter and it is clean as well, and both tanks were dropped and cleaned a few months ago so theres not years of buildup in there. While I dont have a gauge to measure fuel psi, its basically shooting a stream of it over the driverside fender, so I know from experience that is fine. I have a new set of BB's from Russ sitting in the back seat and a rotunda timing meter at my disposal, so I may just bight the bullet and order a ump from Mel.