Scotts_D250

Well for the past few weeks i have noticed a Haze at idle and when i get heavy on the gas but i thought nothing of it because it would only do it every once in a while. But today it started to worry me, after getting heavy on the throttle it didnt go away like it normally does. Its hard to notice but you can see it go past the window when the wind is blowing.

What would the problem be? Dirty injectors? its a 91, orig 193k miles.

sorry i ask more than i input, I'm new to the diesel scene, i hope soon i can start giving back to this fine community.

Thanks,
Scott.

ofcmarc

Could be dirty injectors. I would start with checking the air filter though.

Tron

Check the fuel filter and lift pump pressure. That is the same thing ive been dealing with and am about to install a new Air dog lift pump to hopefully fix this. I suspect now that the last lift pump is no good or maybe more air but no external leaks. If it comes and goes I would look into these for sure.

rcurrier44

Is it when it's cold? If so check out your KSB sol.

IRoss

Tron, do you run a FP gauge? I recall that we both have the same problem with haze from the 190's....I wonder if a higher fuel pressure would help the injector to atomize a little better..I experimented with the fuel screw but that did not seem to make a noticeable difference...pdr checked my sticks and told me there was nothing wrong with them, and I still get a steady haze with my valet on and the pump turned down or up..my fp is steady at 5psi usually....

Tron

I don't have a gauge yet but will soon as I am installing an Air dog 100 on the weekend and would like to know what its doing. It should put me anywere between 10-15psi from what i was told. Every one gave me a different answer. I hoping this helps with my haze and lack of power. every now and then it runs good but it only lasts a few minutes.

I was wondering if air could pass through the o-ring on the little pin that runs on the fuel pin. I suspect I have a air problem with out a external leak.

I also just had my Injection pump off and the injectors out and sent back to the pump shop to double check. They said the could no find anything wrong and turned the pump up some more. This just gave me more smoke and a bit more throttle response. I can barely get my pyro over 1000deg's and before with the stock injectors and stock IP turned up I could pass 1500deg's. Maybe that lift pump is a problem. I will know Saturday. At idle it is giving me 7psi.

wannadiesel

You didn't by chance replace the return line banjo bolt with a high flow banjo bolt, did you?

Thunderhog

O.K. Wanna, I have been watching this thread as I too have a haze at idle problem I have been chasing since my conversion. Nothing I have done has made it better, or worse. The Injectors were an unknown so I bought DDP 40's as they have a great reputation, and was truly hoping they would help my problem. They did not. however, it does run better, and cooler. I was looinkg at this thread as I had a discussion in another thread about lift pumps, and was hoping to see some clarity here. Now I need to check my return line Banjo bolt??? Egads! How in the blue blazes would I tell?
Thank you in advance!

Tron

I have not installed a high flow return bango bolt. The pump shop supplied me with 2 both times they had the pump. They just replace them in-case they are restricted. And yes it is the stock size as have removed and installed both and did side by side to the original. Thanks though

Just curious....why would anyone put in a high flow return bango?

Im all set to install the new pump Saturday, I will keep everyone posted.

wannadiesel

It ought to have a little tiny hole. It's a restrictor that serves to keep the case pressure up but folks who don't understand the fuel system have tried to "free up" the fuel flow.

OK, just making sure you hadn't done something crazy and forgot to mention it.

Tron

Ok, so the new Air Dog 100 is in.

The results.

I notice more response and less blue smoke but not by much. It does pull a bit better over all. I backed out the smoke screw a whole bunch to help with the low boost smoke but I still have a lot of smoke especially after sitting at a light. I seems to build up and then when I leave the light it clears in a big cloud of greyish blue smoke.

I still don't have a fuel pressure gauge in there so I can't tell you the pressures. I know this is very bad, its in the works.

I plan on adding some more timing to see if this helps as it is stock from when I reinstalled the IP after having it checked. Still can't break 1100deg's so Im going to turn it up some more.

Thunderhog

I ordered a fuel pressure gauge, and intend to see just where I am at. I think its running out of fuel at wide open throttle, It falls on its face at about 2600-2700 rpm (not like a gradual de-fuel) The boost drops off and it slows just like its starving. before the 366 spring it would just stop accelerating when it de-fueled, like running up against a rev limiter, or throttle stop. Now it actually revs up and then slows down until it shifts. I think it has 5/16" fuel line too! (what was I thinking?) When I put the truck together it was bone stock except for the Banks Intercooler. now, not so much. It is a disease! I just cannot leave ANYTHING alone.

wannadiesel

Pull the downpipe and an intercooler boot and look for oil.

rochauler1

You may also want to check the valve clearance (run overhead) this is what cured mine.

Thunderhog

No oil in either, and I have moved the lash tighter and looser, just to see what happens. The only thing the lash change did was make more noise the looser I went with lower EGT and slower spool up, and tighter made more heat and spool up faster (a little, VERY little). I keep records of all modifications, and or changes, and the results. (old habits) one thing that is an unknown, is fuel pressure. And I should know better. I received my fuel pressure guage today, a 270 degree 15lb autometer electric. I am going to install it post filter as the filter will have some pressure drop. The other thing I wan to try is more timing. I have to be careful as I tow long distances (although not "heavy" by our standards) about 18,000 lbs (gross) at most. I have seen piston cracking problems with too much timing. Dave, as most people use the "I have my timing 1/2" fom the head" method, I just cannot do that. It amounts to "advance the distributor till it knocks, and back it off a little". Will it work, I suppose, but you never have a point of reference after that. Can you shed any wisdom on how many Thousandths, or MM past straight up you would suggest? I have the tools to do this, but not the wisdom of how much to increase it. I am also gathering the parts for a low pressure Piston lift pump, and will be changing pre pump to -8 and post to -6. However I will NOT change any fuel related item untill I run some pressure tests first. I thank you for any input. and I will post all my results.