(800) 853-2651
SHOP NOW

F250 miss

M

Mike(NEOhio)

Well-known Member
Location
Newbury, Ohio
My '99 250 SD, 5.4, 221K with no major problems ever. It developed an irregular miss in hard acceleration and on hills. Sometimes rough idle. Radio was ticking with the miss so I figured ignition. I put a new set of plugs along with new exhaust system, including converter. Resistance in all the injectors is within spec. Coils are all 1.0 to 1.1 ohms. The miss is still there but no radio noise. Wondering where I should look next? I haven't cleaned the throttle body and EGR for a while, used to do it every year or two.
 
Check for a vacuum leak. On the side of the intake there are rubber elbows that the vacuum lines hook to. They will deteriorate over time. Rough idle and miss on acceleration usually mean engine running lean.
 
Can I disconnect one coil at a time to find the miss? I still get ticking on the radio in AM. Monday is my birthday and I have to get it through Echeck to get my new plates.
 

Looks like you have the money to throw at it... A 8 pack of ignition coils would eliminate VERY COMMON coil issues...

Its very possible with a good scanner it may pull up the miss fire counter and point you to the cylinder in question when the event is misfiring are in generic mode, mode $06 test $53 has the events recorded... Mode 6 has not been much help to me unless its a 2005 and up...

A ohm test will tell you if the coil is bad but it will not verifi the coil is good... If it ohms out bad its bad, if it ohms out good it still may be bad... Sorry but that's the way it is...
 
Does it have a miss history that you can scan? If it does I would first swap a coil pack off the cylinder that's missing with one that isn't a see if the miss moves. If it does you know the problem if not I would move an injector. That's where I would go if it has a miss history in the ecm.
 
Does it have a miss history that you can scan? If it does I would first swap a coil pack off the cylinder that's missing with one that isn't a see if the miss moves. If it does you know the problem if not I would move an injector. That's where I would go if it has a miss history in the ecm.
 
If you are getting noise on the radio look under the hood when it is dark out and the engine running. It most likely cross firing from a coil or wire to ground.
 
You should be able to pinpoint the miss by checking for codes. A misfire of any significance or repetition will set a code for sure. The ticking in the radio would indicate a secondary arcing over. since these are coil on plug systems, it may take a bit of ingenuity to find the problem.
As a side note, you should NEVER clean the throttle body on a Ford product since about 1990. They have a special treatment on the edge of the throttle plate that is meant to seal the outside diameter of the throttle plate to the throttle body. They use a calibrated orifice in the center portion of the plate for idle minimum airflow. In many cases, cleaning the throttle body renders it unusable.
 
As a side note, you should NEVER clean the throttle body on a Ford product since about 1990. They have a special treatment on the edge of the throttle plate that is meant to seal the outside diameter of the throttle plate to the throttle body. They use a calibrated orifice in the center portion of the plate for idle minimum airflow. In many cases, cleaning the throttle body renders it unusable.
Click to expand...

That throttle body cleaning or warning was mainly in place for the dealer techs and warranty purposes. Yes there was a coating on the throttle plate to resist build-up but it doesn't last forever. With older vehicles, these coatings wear off or simply become ineffective, so cleaning is the only option other than replacing. Of course you might want to disconnect power to the PCM or a battery cable to reset KAM or base idle.

Back to OP, and like others have said, I think you probably have a coil or coil boot going bad. Until you get a misfire code or have a higher end diagnostic scanner/machine, you will be stuck guessing which one it is.
 
(quoted from post at 04:12:01 08/17/15)
As a side note, you should NEVER clean the throttle body on a Ford product since about 1990. They have a special treatment on the edge of the throttle plate that is meant to seal the outside diameter of the throttle plate to the throttle body. They use a calibrated orifice in the center portion of the plate for idle minimum airflow. In many cases, cleaning the throttle body renders it unusable.
Click to expand...

That throttle body cleaning or warning was mainly in place for the dealer techs and warranty purposes. Yes there was a coating on the throttle plate to resist build-up but it doesn't last forever. With older vehicles, these coatings wear off or simply become ineffective, so cleaning is the only option other than replacing. Of course you might want to disconnect power to the PCM or a battery cable to reset KAM or base idle.

Back to OP, and like others have said, I think you probably have a coil or coil boot going bad. Until you get a misfire code or have a higher end diagnostic scanner/machine, you will be stuck guessing which one it is.
Click to expand...

I agree I have cleaned my fair share and never seen a issue come about because of it...

I don't buy plug boots anymore it seams every time I do soon down the road I have to replace the coil so I wasted $10 are $80 on a set plus my time... I did not make it, it is what it is...
 
I have cleaned it several times over the years and it always ran better after cleaning. The passage from the EGR is on top just back of the throttle plate and I've had the plate get sticky.
I tried disconnecting one coil at a time and listened for the radio noise. I think I found the one but I'm going to look for a scanner tomorrow.
Thanks for all the opinions.
 
(quoted from post at 06:48:40 08/17/15) I have cleaned it several times over the years and it always ran better after cleaning. The passage from the EGR is on top just back of the throttle plate and I've had the plate get sticky.
I tried disconnecting one coil at a time and listened for the radio noise. I think I found the one but I'm going to look for a scanner tomorrow.
Thanks for all the opinions.
Click to expand...

I think the radio check is a good catch let s know how it goes...
 
You must log in or register to reply here.
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top