300 still missing when cold
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More Turbo
Joined: Jun 2001
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300 still missing when cold
for some of those who may remember, my 88' 300 has a miss to it when it is cold, it quickly goes away though when the engine is warm. I recently replaced the coolant temp. sensor and the air charge temp sensor. neither helped. it does not feel like a miss in any one cylinder, just feels like a total lack of pulling power. I am thinking that it is somehow related to the fuel mixture, but I am not that familiar with all of the fuel system components. This morning when I left it was about 45 deg. and I was barely able to take off even in 1st gear(granny gear). I would like to get this fixed before winter. any help is appreciated.
Junior User
Joined: Sep 2001
Posts: 53
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300 still missing when cold
My truck has the same problem, so I just let it warm up every morning(10-15 mins). I was late for work one day so I drove her cold. Trust me, thats a dangerous thing to do. Let it warm up first!!. If you have a dead cylinder, check for spark, then you might think of changing the plugs. One of the plugs might be fouled. Anyhow, I've seen a bad wire act up only when the trucks cold, and I've seen a bad plug foul only when the trucks cold.Always assume the simplest solution! Check for small things first. I never did, so thats my piece of advice to you.
Posting Guru
Joined: Mar 2001
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300 still missing when cold
I think you're on to something. Typically, on my old carbed '79 if the electric choke is "choking to hard" the engine bogs bad like it's too rich. Gotta find someone who knows the EFI's good. Funky sensor I'd guess...
Senior User
Joined: Oct 2001
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300 still missing when cold
I told the old man that when I try to drive the rig when its cold I have nothing but probs and you know what he told me? Dont drive it when its cold. I have been all thru this rig trying to fix the prob and my conclusion is that my 300 is a cold blooded animal with an attitude. so I just let her warm up in the morning(again 10 -15 mins)
Junior User
Joined: Sep 2001
Posts: 53
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300 still missing when cold
I pulled what Ford calls a electric choke, and put on a manual. The electric choke never worked properly from day 1, the manual does the job. You can not drive the truck cold(80% of engine wear occurs when cold) . The carberator is simple, yet can be stubborn at times. 2 simple adjustments and they have to be set just right.Oh I forgot to mention,if you plug the truck in It takes half the time to warm up.Don't forget never drive her cold, unless you have a manual choke and the hi-idle remains on then you can attempt driving cold.
Senior User
Joined: Oct 2001
Posts: 157
Likes: 0
300 still missing when cold
I had the same problem and just figured it was mandatory to allow the 300 to warm up. after reading your post I was inspired to tear it all apart untill I found it.I DID!!! here it is. I checked the plugs and they were fouled(carbon-too rich). so I checked my ignition and everything turned up fine. only one thing left the carb. I checked the float. should have been 3/8" was about 3/16". checked the metering rod. no specks ,just procedure from ford manual. It was off 3 turns. put it all back together, started right up and drove perfect(cold). had a slight flat spot that I corrected by increasing the choke one rich. Its hard to belive that Ive been running with this cold problem for years when it was so simple to fix. hope it helps
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