excessive white smoke when in gear at idle

KingS

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Nov 29, 2006
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Ok guys need some help on this and no one has figured it out yet, three weeks ago my truck just all of a sudden I came to a stop and I noticed white smoke at idle alot and you can smell it strong plus lost 200 rpms at idle. Before this I could hit 50 psi in a snap of a finger and hold it there with wastegate wide open but then after this it would only hit 44psi so checked injectors dv's and holders I had a bad holder so changed plus a injector got somthing in it so got that taken care of, thought that would of been my problem, nope same thing plus now a week later I can only hit 39 psi and it is rolling black coal like it allways has since I had my injector done what could be causing this plus it seems doggy now too please give my idea's I have had about enough with trying to figure it out.
 
yeap right on at 17.25 only thing I haven't done is check fuel pressure but not sure on what it should be and how to tell if it is a liftpump issue or overflow vavle or pump it's self
 
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does any one make a aftermarket overflow and if so what is the difference and how does it help. Plus who has it if aftermarket ones are out there
 
No one that I know of makes an aftermarket one, a replacement one is around $50. If you want to go aftermarket you can buy a adjustable fuel psi regulator and install it down stream of the inj. pump, but things will get a little more complicated. So if you want to keep it simple and just spend $50 buy a overflow valve. Also you can pull the old one out and stretch the spring out thats in it, reinstall it and see if that helped the problem. Or you can hook a psi guage up and see what psi you have.
 
When the 24v trucks smoke white at odd intervals, we always suspect worn-out valve guides now. But on this one, I would guess something is up with the fuel system if you're losing RPM at idle. Checked the fuel filter? Filled up at a different station?

brandon.
 
ok guys thanks for suggestions so far I will start by checking the fuel pressure and go from there to so what I can find hopfully I don't find it's the pump it's self would just hate to have to buy a performance pump that would just be terrible news at least to my wife's ear's any way.:rockwoot:
 
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By the way if you end up replacing your O.F. valve you can pull your old one apart and rob the shims out of it and put some of them in your new one and presto you have a higher psi O.F. valve.
 
Well replaced overflow valve not the problem so went and bought a fuel injection tester kit to check fuel pressure well unless I'm doing it wrong it pulsates bad. At idle it pulsates from 17 psi to 30 psi, and then when reving it up slowly it will pulsates from 30 psi to 50 psi, and once you get to 2500 and hold it steady it falls off and pulsates from 0 to maybe as high as 2 or 3 psi. Am I doing somthing wrong of is that right and if it is what part is bad the lift pump? Or somthing else and what are way of fixing it buy a lift pump or some other alternative else.

thanks again in advance for replies.

Ok guys went out to so my wife what it was doing on the fuel pressure gauge and now it wont' drop to o like before but still does the other pulsateing stuff any info please plus should the gauge read pressure when truck is shut off or should the guage slowly like a matter of 5 secs drop back down to zero. Oh yeah I am using the air bleed hole on the banjo on top of the filter that is where the local injection shop told me to hook it up to.
 
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Put a valve on the guage and just crack it open, this will slow the pulses of the pump until it reaches a steady psi on the guage. After you put a valve on your psi guage let us know what it reads. Have you checked your fuel lines? The rubber fuel lines at the back of the engine on the side of the tranny get old and crack and start sucking air. I would check them to rule them out, if you haven't replaced them you probably should, just to keep from having to deal with that problem. This usually causes hard starts. Also how does your coolant look?
 
now hard starting and coolant is great and so is oil I got the truck back from Schied's a month or so ago from having it fire ringed and 14mm head studs. then 1000 miles after I got it back this happened and no one can figure it out I also have a hesitation slash miss in the motor when you rev it from idle to what ever rpm by pushing hard on the pedal. if reved normal you don't notice it.
 
If you still have a stock fuel delivery system the pressures you stated sound normal for a piston type pump. What you could do is pressurize the fuel tank with compressed air (about 10-15psi) and watch for any leaks. This will give away any leaks on the suction side of the lift pump. I have had a few with the fuel heater sucking air and causing some similar problems. Hope this helps.
 
ok guys latest check on this problem I posted about fuel pressure took it for a drive with the fuel pressure guage hooked up pressure read like I said until I push it to the floor then the pressure drop to 10 psi and allitle under and doesn't pulsate the needle is steady what is your thought on this could this have anything to do with my problem of smoke at idle and if so what it the fix thanks.
 
Sounds like you have an injector issue, i see this problem a lot.
 
I just had my injectors pop tested and clean by JL to make sure that wasn't the problem I had one stuck open but that is now fixed and that is why I posted this thread is to see what else to check and to confirm my findings as I diagniose the problem thanks again for replying though.
 
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New Finding Today

new findings on this problem.
I took the lift pump off and the rubber line that runs between the fuel heater and lift pump was dried out and cracked, no fuel leaking out of it but once I took everything apart and emptied all the fuel, I staighted out the rubber line and fuel and air bubbles came out of the crackes and the line had nothing in it flacked off some of the line where the cracks where and there is diesel fuel inbetween the webbing and outer rubber of the hose so that is some of my problem for sure. Need to know where to get this line or what hose to buy to replace it with. Plus I need to know if the above post about my fuel pressure when WOT is normal or is the lift pump bad to. Anybody that know's the answer for sure reply please so I know if I need to buy a pump tomorrow along with the rubber hose thanks guys.
 
ok guys thanks I will post once new lidft pump is on and I have the rubber hose replaced on if it fixed my problem or not thanks again guys.
 
I have the same problem, truck smokes white at idel upon startup and clears up once warm. I replaced the rubber lines, all except for the large one, lift pump and overflow. still not fixed so im not sure what to tell you.
 
I know you posted that you had injectors tested, but do you have another set you can put in? I have run into this problem twice now and it was an injector issue both times.
 
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