I have been reading so much i think my head might explode. about the time i think i have a grasp on what might be going on i start reading and there goes the grasp.

So here we go.

E99 f250 superduty 4x4 crew cab 7.3 psd automatic 188,000 miles stock ride height. It has a tuner? Small ****, little box. I keep it turned down low. I have owned the truck about two thousand miles.

Bad shudder or lack of power at lower rpm, 1400. It just doesnt seem to be as strong of a running truck as i thought it would be.
It seems like it has to be wound up to 2000rpm or more to produce good power. It doesnt feel like a miss or shudder at the higher rpm's, but does at the lugging rpm's. Maybe thats typical.

I am not sure if it should be described as a miss or shudder.

I have replaced the air filter, fuel filter, and engine oil and filter. 15w40 Rotella.

The SES light is not on. The OD light is not flashing.

Is it tranny or TC problem?
I get a bad shudder when i am cruising in OD, 45-50 mph, about 1300-1500rpm, and give it light throttle.
If i mash it in OD it downshifts and away we go without shudder.
If i click off OD button, the rpms come up and i can throttle up with no shudder.
No shudder when starting off. No shudder on decel or coast.
Slower speeds i dont really feel it. Maybe at 30mph, but very slightly.
The OD light is NOT on.

The engine starts good. No smoke at start up and i havent ever seen smoke when it shudders. Or any speed for that matter.

It seems to shift better cold than warm. When it is cold, i will count the shifts and it will be in 4th,OD, and be running higher rpm's. When it hits full operating temp it drops rpms, TC locking in?, and starts the shudders when feeding it slight throttle.

Will injectors create a miss or shudder feel also. The idle doesnt seem real smooth, but i dont have a lot to base it on.

I checked ex manifold temps and it seemed the passenger side, front cyl. was running a lot colder than the others.

I need to get this nailed down before spring and i start towing. Or before it does major damage.

Will haveing it scanned give me any definates on injectors and such? Will it give me any tranny info?

I have fixed a lot of little issues on the truck with everyones help on here, hopefully you guys can shed some light so i can take care of this. Whether it is tranny, tc, injectors, or what.

Thanks in advance, Ken

I think i need to go find some aspirin.

 

nice write up and way to use the search function!! and welcome to FTE.

Do you have the ability to have a buzz test performed?

How does it cold start?

here is a link to a thread from another member, He started out with cold start issues that ended up being injectors. After he rebuilt the injectors (granted he went stage 2) he could not believe the power. https://www.ford-trucks.com/forums/9...ease-help.html take a look at page nine and you will see his results username is lostman

the fact that you don't have a SES kind of leads me to believe the HPOP may be fine.

Someone please correct me if I am wrong but your post really describes worn injectors to a T.

Good luck

Steve

EDIT: post up your location, someone local to you may have an AE and be willing to take a look at it for you.

 

here is a bump, should be getting more responses?

 

I have the same shudder/problem. Mine happens roughly around the same speeds maybe 55 top end, but never before 40mph. I never looked at the rpms range when it happens. I will tomorrow. Like you said always on light accelerartion.

I haven't had it computer checked yet. I have heard anything from injectors to TC. I replaced the fuel filter, and cleaned the air filter. I heard it was a u joint problem. Unhooked them and they were fine for now.

So I am at a loss for now.

I prefer the advil's for my headaches.

 

Your symptoms sound like my truck about 4 weeks ago.
Turns out the problem was a bad injector. In my case #7 was not firing. I replaced that injector with a remanufactured unit and rebuilt the others with a Rosewood kit. I sorta messed them up at first but then I realized my mistake and corrected the situation, but that is another story for another day....

PM me if you are in the Phoenix area and we'll use my AE to pull any codes that may be stored in there.

If you don't have access to a scan tool, you may go with your instinct and check out the cylinder that you said was a bit cooler than the others. Pull the valve cover, start the engine and see if oil is squirting out of the discharge port. I find it much easier to get the passenger side valve cover off by pulling the front tire and reaching in through the fender well to get those two bolts by the A/C unit.

You may get lucky and find a loose connector somewhere....

Let us know what happens and we'll see if we can offer any more suggestions.

Good luck!

 

My truck does this when I haven't rotated the tires in time.

Changing injectors didn't do anything for me, and I have a full built trans. And I'm live tuned.

 

Thanks guys.

I am in Illinois, just across the Mississippi River from South St. Louis County. Interstate 255 and exit 9.

Cold start i think is good. Upper teens it starts ok. Slight puff of smoke, but not really any of the romps.
Plugged in for a couple hours it fires right up. Even when it was in single digits. No smoke.
Only time it failed to start, it was 0 and the plug on the block heater was bad.
New it was the plug from ohming out the heater with specs and info from this sight! Thanks.

I have a friend that said he can scan it. He has wrenched on these motors alot at his work. He has been getting overtime here latly. I just have to be able for us both to be freed up. I am going to call him today. I'll do the old "hey buddy, watcha doin tommorrow?"

Phoenix, warm, sunshine, I could use some of that. Just a bit far for me. But thanks for the offer.

I might pull it in my shop tommorrow and ohm out the harness. Maybe pull the valve covers.

I have been around quite a few motors, gas 2 and 4 stroke, a few big diesel trucks, but this is my first diesel pickup so i dont have much to base on.
When i test drove the truck the owner said to push in the OD button anytime you were at speeds under about 50. Said it was easier on the tranny. Yea and it doesnt chuga, chuga. Humm
My friend with 390,000 on his 7.3 said he never has done that.

Thanks for the help. I look forward to getting this issue tankin care of so i can move on to some of the other mods i want to do.

Thanks Again, Ken

 

You're not gonna find any codes on your trans if the OD light isn't flashing.

How long has it been since you rotated and balanced the tires?

 

I was told about the tire rotation. I went to Belle Tire here in michigan and they did it for free since I bought the tires from them.

 

And it didn't do anything for you?

I found that it was not RPM dependant on mine. Which is what first led me to dismiss the engine contributing to the issue.

Like I said though, it does it when I don't rotate the tires in time. Very subtle shudder starting around 38 and going away around 48.

It does it every set of tires that I don't rotate often enough.

It's done it before and after injectors, before and after a built trans, before and after live tuning, etc...

 

Thanks for the replies,

This isnt necessarily a speed related issue. I can click it out of OD, maintaining the same speed but with higher RPM's and the shudder goes away. A tire issue would be speed related. But i do appreciate the input.

When it is doing the miss/shudder, 40-50 mph, 1300-1600rpm, approx, in OD, it will rattle your teeth and feel like it is going to shake the truck apart. But will gradually smooth out as the RPM's come up. But no smoke.

My friend with the scan tools is out of town. But that i believe is my next step.

Any other ideas or thoughts will be appreciated.

Thanks, Ken

 

Same issue here. haven't had time to go to the dealership where a friend works to get it checked out.

 

I didnt get to tear into it this weekend.

Going to try to get something set up with my friend this week or weekend. I will post anything i find out.

Thanks, Ken

 

Nope, the tire rotation didn't help. But, the good note is that I know they are balanced now

 

I talked to my freind and it looks like we will be scaning my truck this weekend.

Hopefully we will find something.

We took the camper to the dealer this past weekend. Truck seemed to do ok as long as the rpm's were up around 2000.

It got just over 10 mpg. Doesnt seem very good. About a 100 miles of around town driving and 150 miles towing the camper. Camper weighs around 8000 lbs.
That is up and down hills from St. louis to the other side of Lebonon, Mo on I44.

I will post what we come up with.

Thanks, Ken