rough starting

[JB]

hey guys since the weather has cooled off ive noticed that my truck is idling rough only when i start it after it sits overnight... so far it has started every time but when it starts its idling rough... after it warms up it runs great... and its never had this problem before. im getting worried cause its about 40 or 50 degrees and its gonna get allot colder here real quick... do you think it could be the fuel heater? or maybe that i need to change my fuel filter. . even though i changed it about 2000 miles ago... ah well any input would be greatly appreciated thanks

 

[pepecat]

I've heard of this happening once before. Was as you described, and it turns out that the fuel shutoff/KSB connectors were swapped. Try swapping and see if that fixes it.

 

[JGrefenstette]

could have some summer fuel in your tank. do you run any additave?? if not you should, for a lot more reasons than just helping the cold start. i use stannadyne, its the best stuff in my opinion. perfomance formula. fantastic. really improves cold starts and idleing, when cold. your best bet though is probly just go to walmart and get some diesel 911 i think its a red 1 quart bottle. that should help untill you get some winter fuel.



is your grid heater cycling? if its in the 40s and sits over night, it should be coming on. if its not, that could be a part of the problem, if its not heating the intake air and causing incomplete compustion cause the fuel is not reaching proper temps, and there are a few other factors as well. ifs its not working, check your grounds and clean up the connections, then check your voltage inthe heater circuit.



hope that gives you somthing to chew on.

 

[JLEONARD]

At 40 deg F it won't be a summer fuel issue. At that temp the fuel will be fine.

Mine always started fine without the grids until it got into the 20's... fiorst or second compression stroke it would pop... . run smooth but maybe 50 rpm low until it warmed the cylinders... maybe 1 minute.

I also doubt it's the filter. That's more of an issue at power.

Couild be KSB but then again I never really understood how that works... I think Greenleaf understand it well enough to explain it (again).

It could be a little bit of fuel drainback/ a little air in the sytem coupled with cold cylinder temps.

 

[Tippin Spotted Cow]

As I understand it, the KSB cuts the flow down to the fuel pump, so when the pump starts pushing fuel in, it takes just a little bit longer in the stroke to build up "pop" pressure for the injector to open up and spray the fuel in, thus retarding the timing. I may be off by a few light years though... so don't take too much stock in what I say.



I have noticed that if you crank the pump up but keep your stock injectors, the thing will get an awful idle in cold weather and start pumping white smoke like nobody's buisness. Mine did that for a while, and it actually cleared up a lot when I put in some larger higher flow injectors.

 

[Grey Wolf]

Basically the KSB solenoid is there to advance the timing below 90 degrees. It receives a signal from the rear most switch on the intake manifold. It' s also not repairable, if it's not working you need a new one... ...

 

[Bob Beauchaine]

The KSB advances timing slightly to aid in cold weather warm up. After the engine temp reaches 100 degrees power is cut off to the KSB as the engine is warm enough to run normally. I can't remember what the supplied voltage is to the KSB when cold - 9 volts - I think. Check the stickies for voltage. If you can't find it there let me know and I will get it for you.



Bob

 

[Tippin Spotted Cow]

Eh... I tried... . mine hasn't worked since I got the truck anyway.

 

[Grey Wolf]

It's 12 volts Bob...

 

[JB]

well thanks for the imput, im gonna check some stuff out this weekend... last summer i had the ip rebuilt and turned up 10% and im now wondering if thats whats going on ive got stock injectors and im also running veg oil on a two tank system... but ive checked the valves and there great... ive also been running stannadyne for about a year or so in my diesel tank and im very religious about it... so with that im left wondering about having the ip turned up... but like i said it has never done this before... hummmmmm. . oh also how would i check if the ksb is functioning properly? i know you said it should be receiving 12v but how do locate and get a reading on this? well thanks again...

 

[Grey Wolf]

If you apply 12 Volts to it you should feel it click if it doesn't it's dead. If it's working check it when it's cold again, have someone turn the ignition switch on while you listen or feel the KSB to see if it's clicking. If it isn't then your air temp switch is dead. Clear as mud?



Sorry just read this again, the KSB solenoid is on the side of the Inj. Pump. I has a solid line on the front of it and the electrical connection is on the back end of it. .

 

[JGrefenstette]

hmmm. veggie. i wish id known that youd been running that, before i made my first post. i got very close to converting my truck to that. a guy i used to work with had his own buisness installing those systems. after being at diesel school and talking to many instructors about it, one of which makes his own bio-diesel and has done multiple tests on differnt fuel types. i found that the veggie is detrimental to the health of a diesel. they tore down a diesel that had been running off veggie, with little more than 20,000 miles of veggie, and they said it was an awefull site. rings were glazed and siezed up. also the veggie contains glycerine that if i remeber right, has water molecules in it. either way i know the veggie has water molecules in it, that can only be removed by boiling them out our water washing the oil, which is an interesting process. the water molecules are not a friend of the injector pump, injectors, or any othere function of the engine for that matter. i hope im wrong, but you may be experiencing problems that have been brought on by the veggie, and its effect on the engine.