jgn

When I first start my truck and the motor is cold the rpms will stay at 500 or right below and they will slowly increase over a few minutes time till they are at the normal setting which is right at 1000 in park, also will be putting out a lot of white smoke during this time. Seems the colder it is the lower the idle is when first started. Any ideas on why this is occurring?

Lil Dog

Have you had your timing set/checked lately? Late timing would attribute to the white smoke you are seeing cold. The low idle increase is normal, at least mine has always done it. With the DDP injectors, it tends to start loping at low idle speeds to try to maintain idle speed until its warm.

dieselman2300

My truck does the same when idling.
Are BOTH of you grid heaters working? I just had the same problem, you could hear and see the relays working, but it would still smoke on startup. I checked bothe of the grid heater relays on the driver fender and only one of them was coming on.
Also, like Lildog said get your timing checked.

xzaq103

how cold are we talking? Mine when i start it is about at 600 RPM and does not want to run after it warms up she idels at about 850 give or take 50 RPM. Mine also smokes more at startup as did my other two. But this one smokes more Im thinking about getting my timing checked and set at 15.5 Ill keep ou guys infromed on my findings.

Chris

John Faughn

There could a lot of things , 95 is that the original injectors , timing / slipped , fuel solenoid linkage adjustment .
Like everything , only testing will tell , list of possibilities is what to check , injector popit test & spray pattern , 1000 RPMs at idle is high .

kas83

1000 in park when warm is just a little high, but not bad. Both of mine have a low idle when cold, and have white smoke when warming up. But then again, it's cold enough now for the trucks to smoke white when running around town too. Both trucks have a lope when first fired, the 97 having enough to rock the truck back and forth. Other than that, both start great and run good. I can move both immediately, even with the low idle. I don't recommend it, but the last snow storm required both getting moved very quickly.

jgn

My timing is or was at 13.5* I don't have the tools to check or set it but am hoping to find someone close to me that does that might be willing to help me with it for a few bucks. As far as I know they are the original injectors don't know if a previous owner changed them or not. When you say late timing are you referring to retarded or advanced? The fuel solenoid is opening all the way. Can retarded timing cause a dead miss in these engines or should I be checking for a bad injector maybe. It runs strong still but if cruising right at lock up speed it's like being on a brahma bull when it locks up. I'm looking at a different truck right now and want to try and get this one back to running good so I'll be able to sell it. All your advice is appreciated. I made an adapter today so I can hook up a fuel pressure gauge just to rule that out as a culprit. If you hook a clear line up in the return path to check for air in the system should there be any air bubbles at all in it, or is a few expected due to circulation? It starts up okay so I don't know if this would be a cause or not. Can the lift pump or injection pump introduce air into the system only while running if somethings wrong with either?

John Faughn

There are a lot of places for air to get in , check for weak cylinder , remember its a cold symptom , so check cold , crack the injector lines , one at a time , what your looking for is any that there is little or no change in eng running , that is the one that is not working /much .

jgn

A little update, I hooked a gauge up this afternoon and checked my fuel pressure. I had around 12 psi at idle and could manage around 20-22psi at 2000 rpms. I removed and stretched the spring in the OF valve, after this I had 17-18 psi idling and around 30 psi at 2000 rpm or right above. It did seem to idle a little smoother after this. I then ran the rpms all the way up and as soon as I did the white smoke started rolling and the fuel pressure dropped to around 15 psi. Could this be a timing issue and that causing the miss to be more noticeable, could I have a rubber line collapsing under full suction from the pump? It still has a miss in it and jerks like crazy when traveling at lockup speed till the rpms increase. Any ideas on where to check next? I'm not really worried about the low idle part of it since most everyone says this is pretty normal but would like to solve this other problem. Thanks for the replies.

John Faughn

Get a new OFV , stretching the spring is not a fix , your pressures are still a little low .