Rough cold-start idle, now no start...

[Furthur]

It's been idling very rough until warmed up as the temps fall this year, never used to do that. Always started and ran great, even very cold.



Went to start wed. morning, on my way to the airport (of course), and the GFI musta tripped, 'cause the led on the plugin wasn't lit. Well it started, 'bout 3rd or 4th compression, but ran really rough. Jammed a 2x4 onto the pedal for a fast idle and went inside to get my stuff. When I came out, it was dead, and would not start. Good cranking power, but not even a hint of firing. As I was gonna be late for the plane to go to work, I had my wife drive me instead, so it sits at home, waiting for me to get back and fix.



Been reading and searching, and sounds like I need to check; fuel filter, KSB, FSS, Grid heaters (pretty sure they're ok, but will check), fuel heater.



Now, lots of you seem to think it should start fine without any of this stuff, down to below zero (it's only about 10 F). So I'm thinking either FSS or gel (I have been adding stanadyne). But what about the rough idle when cold? I'm still thinking KSB on that...



What else am I not smart enough to ask?



Before you ask, I need a new fuel filter. It has 0W40 synth in the crankcase. Good battery. Pretty sure the grid heaters are working.



John

 

[Jgolden]

Last year I got caught with "summer" fuel and had problems similar to yours. I added everything in the book and got started, but not a good sound. I had to keep adding #1 to the tank until it cleared up. This was with fairly warm temps only down in the low 20's.



The place I get fuel says that last year the winter mix wasn't so good at first, but now the problems have been solved. Maybe. It was clouding up at fairly warm temps. I had a magnetic heater I put right on the filter. Not practical but worked in a pinch.



May not relate to your problems. I had to change the filter twice.

 

[JGrefenstette]

well as you already said, id check and replace the fuel filter, and if your able check the fuel pressure. because, i may be way off, but if you have a slightly clogged pickup screen in your tank, or a badly clogged filter, the cold temps, (thickening of the fuel) could cause some seriouse resistance to fuel flow that would not be as obvious during warmer temps. dont be afraid to dump some heavy dosses of diesel 911 or seafome in the tank, after changing the filter, to help clean the injectors and whatever may be in the lines.



because you say it started then was dead after you increased the idle speed and left it. leads me to believe that the fuel is being restricted, and the increased idle caused it to draw more fuel than it was able to supply at the time. could be from bad fuel, coldtemps, clogged filter/screen, or more than likly all the above.



thats my 2cents, an then some

 

[Furthur]

Ok, thanks for the help guys... got it running.

All the heaters and solenoids checked out, per FSM troubleshooting. Pretty sure, now, it was just gelled fuel. The new filter won't hurt, and the full bottle (after half-filling the new filter) into the tank should help... I hope, since it's outside soaking at about 10 deg. F now... I did warm it up good, and ran it enough to move that fuel around a bit.

I hope it's not my 2-stroke lube mix. I've been adding 5 oz stanadyne and 11 oz 2-stroke (approx), for lube, to each tank. No one else has reported gelling with it, though.

John

 

[JGrefenstette]

i wouldnt use the 2-stroke lube. ive used stanadyne perfomance formula for almost 2 years now, and its the best out there in my opinion. ive had a day or two when i didnt have it in the fuel, and cold starting without it is very noticably worse, cranks more to before starting, idles rougher, etc. most all diesel adititives will have enough lubricity for the ULSD that you run in the truck, to keep the pump seals lubed and protect the internals of the pump.

 

[JLEONARD]

I used 2 cycle oil for quite a while in mine. According to that lubricity study it was one of the better values for the lubricity it added. Actually it was right on par, just about equal, with the Stanadyne.

I just couldn't find Stanadyne anywhere around here.

 

[PToombs]

I can buy a gallon of 2 cycle oil at Wallys for the cost of a pint of Stanadyne. The Stanadyne does 60 gallons (right?) and I can get 4-5 tankfuls, at 28-30 gallons, out of the 2 stroke oil.

I haven't had any problems yet.

 

[JGrefenstette]

well i guess its a matter of opinion. ive talked to a number of guys about it, some of the teachers at my school, one makes his own bio and has run lots of tests on fuel and additives. another is a engineer for cummins. but what ever works, i mean if it does the job, then roll with it