Running ruff question? (missing?)

[skintbackfarms]

Just bought a 89' F250 4x4 with 4:10s and started driving it home and it was is missing around 2500 rpm and up. Got back to the office with it and started to hit the pedal, it was blowing out blue / white smoke like raw fuel. What should I look for? He said he put new injectors in it in Sept. The return lines are old, and the pump looks like it is leaking. I am going to bring it home Monday and start replacing things. I want to know what to look for.

 

[RLDSL]

How much oil is it burning? Blue smoke is usuallly oil. If you just got the thing, and it just started up doing it,it might have just burned off a real stout dose of Lucas or other motor honey that the previous owner had poured in the oil to cover up the oil burning and is now inhaling oil like crazy.

 

[fastass350]

First thing I would do is a compression test, though it could be something simple, you could have low compression on a cylinder. I had one doing exactly that same deal, til it grenaded. I'd check it out before you run it much.

Chris.

 

[skintbackfarms]

I don't think it has to do with the oil. The truck is missing in the higher rpms. I am going order a set of injectors and return lines. If it was the oil, it would most likely blowing smoke at idle. Its not doing it until the higher rpm.

 

[4x4TruckinGirl]

I was gunna say injectors maybe.... you can touch each of the injector lines while the truck is running you should get an even consistent pulse from them, I suppose if one of them was off or weak feeling that might have something to do with your issue....

 

[Dsl_Dog_Treat]

Congrats on the purchase.
Now you say the pump is leaking. Whereabouts?

Depending on where the injectors were purchased and either new or rebuilt, I suspecting that you have one or two that are not popping off at the proper pressure. Prolly have a lower pop off pressure than the others.

If you have somebody locally that can test em for ya that would give you the best results. I've seen new injectors crap right out of the box and rebuilt injectors the same but also perform better than new ones. Not much in em to go wrong but enough to mess up the timing.

 

[RLDSL]

If it's at 2500 and up, take the CDR off and see if the thing is clean and working. Above 2500 the CDR should be closing, if it isn't you may be getting some heavy uneven blowby gas pulses getting stuffed down the intake loaded with oil vapour which can make the engine surge and buck or generaly just run rough if it's just getting enough to get the heavy drip down to numbers 7and 8