1995 F250 shakey idle?miss?

[95-F-2FITTY]

Ok guys so my truck had a bad #3 injector so i replaced it and it runs sooooo much better now BUT after it warms up the truck does not idle right and it kind of shakes when its setting there idleing and it sounds like it might have a slight miss.But when i rev the engine up or drive down the road its not missing but when i coast to a stop and put in the clutch or rev it up and the rpm falls back down it has a flutter in the idle where its like it is trying to adjust but it doesnt and it starts shaking/missing again at idle. I have ran a buzz test they all past and i passed a cyl contribution test as well. Any ideas?
Any help would be greatly appreciated! Thanks,Cody....................I should also add that after the injector change i have drove about 300 miles.

 

[mandkole]

Sounds like its having trouble managing ICP. Does it hard start when hot? Did it idle good before the #3 injector was changed? When were all of the orings serviced last that seal the high pressure oil system (IPR and injectors)? How many miles on it?

 

[95-F-2FITTY]

It doesnt just set there and crank but it dont start by the bump of the key.It idled horribly because the injector was dead i took it apart and somehow the poppet screw was broke.The truck has 165,000 on it. I am not sure on the orings at all the previous owner didnt change them so i doubt they have been changed.

 

[ghohouston]

First of all, did you put any miles on the truck after you changed the injector?

 

[95-F-2FITTY]

Yes about 300

 

[95-F-2FITTY]

Any ideas maybe an ipr or something?

 

[ghohouston]

An ipr CAN cause rough idle yes. It is possible to still have air in your h.p.o. system, although less likely with the miles you put on it

 

[95-F-2FITTY]

Alright so i had a CEL light come on and it was for the icp sensor so i unplugged it and that didnt change anything.So would a bad ipr possibly cause a icp light?

 

[Justin@DP-Tuner]

Alright so i had a CEL light come on and it was for the icp sensor so i unplugged it and that didnt change anything.So would a bad ipr possibly cause a icp light?

Did you unplug the ICP sensor when the truck was running? If the idle does not change when you unplug that sensor, that is usually an indication of a bad ICP sensor.

 

[95-F-2FITTY]

I unplugged my icp sensor and it did not change the idle at all but like i said when i first start it when the engine is cool it idles perfect but when it warms up it misses or shakes and lopes. But i also thought that if i unplug it that my truck would idle good if the icp was bad because isnt the pcm suspose to default to like 750psi

 

[Justin@DP-Tuner]

I unplugged my icp sensor and it did not change the idle at all but like i said when i first start it when the engine is cool it idles perfect but when it warms up it misses or shakes and lopes. But i also thought that if i unplug it that my truck would idle good if the icp was bad because isnt the pcm suspose to default to like 750psi

Let the truck get to operating temp, and while it is running, unplug the ICP sensor. If the idle changes, your ICP sensor is still working. If the idle does not change, you are already running the default, which indicates your sensor is bad.

 

[95-F-2FITTY]

thanks justin so i drove my truck tell it got warm on my lunch break today and ran a cyl cont test. When i tried i got a code p1211 "ICP higher/Lower than desired" The switch has intermitent issues so i know i should proably change it but i didnt know if something else could cause it like a ipr. So i cleared the code and tried again and it ran the test and i failed it on cyl numer 3 two times,this is the cylinder i changed the injector on to start with. So i also ran the data stream before operating temp when it idles good the IPR%17/ICP PSI-725 at idle then i ran the data stream at operating temp and it showed IPR%12 /Icp PSI-580 at idle,are these numers ok?
...........................Also when i unplug the sensor there is no change.But if the pcm has switched to default shouldnt it idle right if it was the icp?

 

[ghohouston]

Did you ohm out the u.v.c h. To #3?

 

[95-F-2FITTY]

no but they are new so i didnt figure i needed too. which pins and could you give me some directions if you dont mind lol

 

[95-F-2FITTY]

Alright so i was just lookin at my ipr last night and where the pigtail plugs in i can jiggle the connector side to side in the housing is that normal?

 

[Baker42]

The injector O-rings were inferior for the 94-97 model trucks.spend a day and pull em.
About 83 bucks from Rich Ford here in ABQ. Replace all 8 with the copper washers,and have piece of mind that there done. Then you can go foreward if the problems persist. but my bet is the # 7 & 8 is not in the best of shape. Mine went south at 90000. Also check for oil in the fuel filter. If the fuel is brown or black its a given.Keep injectos clean and free of debris while they are exposed,good luck, Not that bad of job just takes time 6.5 +or -

 

[neverkickn]

Sounds like a bad icp sensor like Justin said.

 

[ghohouston]

Alright so i was just lookin at my ipr last night and where the pigtail plugs in i can jiggle the connector side to side in the housing is that normal?

Unless it changes the idle of the truck while doing it, then I wouldnt worry about it.

 

[ghohouston]

Does your icp sensor have oil in the plug? I never saw that question asked or adressed. And do know that the depending on what cps is in your truck, it can randomly throw #'s 3 & 8 contribution codes, without the injector/u.v.c.h. being bad. Its well documented the grey cps is the cause of this.

 

[neverkickn]

The only info here that is important since we don't have any data to look at is the fact that idle doesn't change when he unplugs the icp sensor. That alone is enough to tell you that the sensor needs replaced.

Also, no offense Houston, but this grey, black, purple, Martian green cps stuff is a crock. A good current cps for the 7.3 from either international or ford will work fine.

As far as the ipr solenoid wiggling a bit, that's perfectly normal. If the nut is tight, you are good.