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Discussion Starter · #1 ·
Hey all, sorry for all the questions, i just want this truck to be restored to the best of my ability.

Posted below is a video of my 1991 w250 right after I started it cold. A rough idle can be heard & im unsure of this is normal or what where to start on troubleshooting this potential issue. I also does this when it is warm.

 

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It's usually normal for a cold engine to run a little rough for the first minute. Is this a intercooled 91?

When it's cold started does it start on the first crank of the starter?
 

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Discussion Starter · #3 ·
It's usually normal for a cold engine to run a little rough for the first minute. Is this a intercooled 91?

When it's cold started does it start on the first crank of the starter?
It is non-intercooled and yes as soon as i turn the key it fires instantly.
 

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Do you have 12v at the KSB all the time?
 

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When it's running just use a meter or test light and check to make sure there is 12v's at the KSB.

Also is your gridheater working?
 

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Alot can cause a rough idle, a low idle will cause that. Valves needing adjustment, bad injector/injectors.
 

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Discussion Starter · #9 ·
Alot can cause a rough idle, a low idle will cause that. Valves needing adjustment, bad injector/injectors.
Im thinking it may be injectors possibly. P.O. said he had them replaced shortly before i purchased it. Though he never provided proof so i dismissed it. The VE pump seems fine. I just replaced the fuel filter and primed it until i saw fuel spurt out the top before i completly tightened. And i also went ahead and adjusted the valves last month, some were way out of tolerences.

Im just concerned of it possibly being a more serious issue such as a head gasket.
 

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You'd see smoke if headgasket. With the engine at idle loosen each injector nut and listen for the engine idle to change, no change then bad injector. Should be able to tell if they look newer.
 

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Discussion Starter · #11 ·
You'd see smoke if headgasket. With the engine at idle loosen each injector nut and listen for the engine idle to change, no change then bad injector. Should be able to tell if they look newer.
It does smoke sometimes a bit on intial start up. In the cold season youd think a new pope was elected. But yes i will also try to crack the lines.

Will alot of fuel be spraying out of the line if i crack it? I just wanna know if i need alot of rags nearby.
 

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They all smoke on cold start up that's the gridheaters job to help keep the smoke down, it's supposed to keep cycling until engine gets up to about 60 degrees.

Some will spray out but you don't need to open them that much to hear the engine sound change if the injector is good.
 
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