Engine runs rough after warm up!

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Oct 20, 2008 | 08:10 PM

dvldog458

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From: Woodbridge NJ

Engine runs rough after warm up!

Any ideas why my truck could be running rough after warm up? It runs perfect at cold start up but after about 1/2 hour or so during normal driving conditions the truck will start to miss,spit,and stall. And when it cools down it runs great again........WTF!
My truck is a 1991 Ford F-250 with 408W and a 9psi Powerdyne. The truck was converted to massair and I'm running 42# injectors w/ a Pro-M 75mm cald for 42# injectors MSD BTM and MSD dizzy.
Any suggestions would be great. It's gotta be something small.

Thanks,
JD

Oct 21, 2008 | 09:12 AM

dvldog458

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From: Woodbridge NJ

I just changed the ECT sensor ...still runs bad after it warms up.
I'm thinking maybe the TFI module on the dizzy????

Oct 21, 2008 | 03:56 PM

dvldog458

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From: Woodbridge NJ

I just replaced the TFI and the coil....still running rough. I will try to pull the codes tomorrow.

Oct 21, 2008 | 04:19 PM

Thumper19

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From: Colorado

Do you have an IAV valve?

Oct 23, 2008 | 09:04 AM

dvldog458

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From: Woodbridge NJ

Thats the cold start idle control right?

Oct 23, 2008 | 02:10 PM

Lazy K

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I suppose it could be a faulty temp sensor but you have got to pull the codes that surely must be stored. Also have you checked your fuel pressure?
By the way, sounds an awsome rig.

Oct 25, 2008 | 12:22 PM

dvldog458

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From: Woodbridge NJ

Just egr code I put the delete kit.....
Fuel pres. is 42

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Oct 26, 2008 | 10:10 AM

G/T

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I Would Say Temp Sensor

Oct 30, 2008 | 08:29 PM

#10

dvldog458

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From: Woodbridge NJ

No cats on this truck.
I did reinstall the EGR valve just to see....its seems to run better.
And at the last fill up I put in 93 oct.

Nov 13, 2008 | 09:56 AM

#11

dvldog458

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From: Woodbridge NJ

Its still running like azz!
I'm going to install a new O2 sensor,ECT,MSD Blaster coil,new plug wires,and run a hotter plug.
It seems like it is fouling out the plugs or O2 sensor....Is it possible to foul out a O2 sen?