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01 f-350 running rough on cold start but runs fine after warm up.

1.7K views 3 replies 3 participants last post by  timmyboy76  
#1 ·
Its been doing this for a while. Pretty sure it is not a glow plug issue as it does this in summer as well & I replaced all the glow plugs about a year ago. I also replaced the GP relay at the same time with a Stancor. I also replaced the IPR & CPS about 15k miles ago. I have done the 50 cent mod on the passenger side( haven't done the drivers side yet).

This is my symptoms. On cold start truck will always start but runs rough when idling. Has almost no power when I first take off. It takes about 10 seconds of driving for power to build up. Until the truck gets up to full operating temp She runs very rough in the 1000-1800 RPM range. Shakes the whole truck. Feels like it is worst on the passenger side. If I get on her (2000rpm plus) she smooths out some but is still running rough & doesn't have its normal power. Once up to operating temp if I get on her a few more times she smooths out & runs perfectly after that. I can shut it down for hours & she runs fine when I start it back up. It's only when the truck is bone dead cold it does this. When it does finally smooth its not a gradual thing it goes from running rough to running perfectly like someone flipped a switch.

I did some reading & thought it may be stiction so I bought some stuff that you put in your engine oil( can't remember the name of it) which seemed to help a bit. It still could be this though I guess.

SES light is not on & no smoke coming from tail pipe at any time.

I have run SVO for 130k miles in a 2 tank system. Even though I have had great success running VO I will admit it may have shortened the life of my injectors which I am suspecting to be the problem.

Before I go buy new sticks I am looking for suggestions on other things I could check first & also what tests I should/can do on my injectors. I know I can get a buzz test done but that only tells me about the electrics of my injectors. If it is injectors I would like to know how many are bad & which ones. If its only 1 then I may just replace that one but if its a few of them then a guess they all gotta go.

Any advice is greatly appreciated.
 
#3 ·
That's very good info. Thanks very much. I will try the block heater as soon as I can.