Low idle speed at start up ?

[DVolk]

The truck runs fine but idles slow at start up . when its warm it runs fine .

A few years ago the injector pump backed off , why im not shure . I also replaced the air tube on the pump as well ,



Any one have any ideas ? Im thinking my lift pump is getting bad ?



Also after the pump backed off when pulling the water temp crawls up a bit but not bad

 

[Jgolden]

There is the KSB. (Cold start deal) How cold are you talking? Mine is an 89 engine so the KSB works differently. I believe on yours it advances the timing until the engine warms up. Search KSB. I just know enough to confuse the issue, but it's a good place to start.

 

[JLEONARD]

You say

 few years ago the injector pump backed off

meaning that the injection timing is now a little more retarded than it was previously?

That would make the idle slower and less power so maybe that's why the engine temp goes up a bit????

 

[DVolk]

I re tightend it up after i noticed it and i noticed it on a bumpy road

after i tightend but ive been wondering what the issue and how to correct it with out pulling the front cover off and completely re timing etc but once its warm it runs fine if i had the extra cash id have pump looked at and a 366

spring put in put i dont want to tackel it heremy self

 

[dpuckett]

A lot of the idle speed issue will depend on fuel quality and actual temp. If your lift pump isnt up to snuff (5psi at hot idle), the engine will idle slower at first start up. Try plugging in the block heater and see if that helps the initial idle speed. I notice the same issue, too, in real cold weather (single digits or less). Truck has done it as long as I've owned it and is otherwise fine, so I just live with it.



JGolden- the KSB in your 1990 (if it's the same as the Dodge version) is activated when power is cut off. The KSB in the intercooled trucks is activated when power is applied.



PS- you dont have to pull the timing cover to time the injector pump.



Daniel

 

[Bob Beauchaine]

If you think timing might be an issue you can advance the timing slightly and see if that helps. As far as air temps we live close enough together - I'm in Portland - so our temps a relatively close. The recent cold snap with low temps in the upper teens did not affect my truck.



Bob

 

[Jgolden]

A lot of the idle speed issue will depend on fuel quality and actual temp. If your lift pump isnt up to snuff (5psi at hot idle), the engine will idle slower at first start up. Try plugging in the block heater and see if that helps the initial idle speed. I notice the same issue, too, in real cold weather (single digits or less). Truck has done it as long as I've owned it and is otherwise fine, so I just live with it.



JGolden- the KSB in your 1990 (if it's the same as the Dodge version) is activated when power is cut off. The KSB in the intercooled trucks is activated when power is applied.



PS- you dont have to pull the timing cover to time the injector pump.



Daniel

Thanks Daniel, my pump is a little wierd, no shut off lever, but it seems to otherwise the be same as the one on a Dodge. May be a 1989 engine.



JGolden

 

[DVolk]

It has been acting this way a few years now , its just annoying since my 90

engine dont do that , and if the timing jumped how would you know if the gears jumped with out the cover off ?

 

[JLEONARD]

and if the timing jumped how would you know if the gears jumped with out the cover off

No one said the gears "jumped"... I doubt that would happen withot a real mess. You said the pump moved. It doesn't take much to change the timing.

 

[DVolk]

How i noticed it was on a bumpy road it acted like a tractor of mine in a bumpy feild real jumpy and burpy iin fact one of the bolts fell out , how im not shure maybe some one tried steeling it ?, or it simply backed off