Truck had a slight loss of power recently. Today I started and immediately heard a miss in the firing. Drove about a mile before it died. Loss of power and rough running. Crank but no start.

Towed it to a Auto Zone that was about 1/2 mile away (lucky) No check engine light, no codes from reader at Auto Zone. Tried to start again and it did, but ran rough with low power.

Towed it home. Its starting now, but running rough and low power.

About a year ago I had the low power / shakes and did the 50 cent mod on the driver sides only. It fixed the problem. Those shakes were worse that what I'm feeling today.

So....which to try in the morning? Replace CPS or go for the Passenger side UVCH?

Thanks!

 

I would pull that passenger side vc and see what you find.Stick a quarter in it.It sure sounds like what you have going.CPS usually does not throw a code.

 

CPS will only cause a no start condition, or dying like you turned off the key.

What is your fuel level? Have you performed the Hutch Mod?

Oil level and condition?

The .50 cent is good preventative maintenance but it is usually accompanied by a SES light when there is an UVCH issue.

 

Read the OPs post wrong.I thought he had CEL....Sorry,Big Al says fuel,sure could be.

 

I do not have a scanner to do a buzz test which is a good way to test. When I was having my rough running issue my neighbor brought over his heat gun and we tested the exhaust manifold on both sides. The passenger side showed a substantial difference in heat. I also put a glue stick to both sides and the drivers side melted it right away and the passenger side did nothing to it.

I opened up the passenger side and sure enough the uvch was off about 1/4in. Put in the Ford clips and buttoned it back up. It fired right up and ran good on my test run.

Just to be safe, I added the clip to the drivers side today. It was also coming off a little but not as bad as the passenger side.

Tim M

 

Fuel level was pretty low, but the light was not on yet. I added 5 gallons by hand and let it run for a bit, but it was still running rough and low power.

The oil was changed about 5 weeks or maybe 1200 miles ago, Mobil Delvac.

Fuel hatch mod. Hmmm.. If it is the fuel/hatch mod problems would the symptoms 'dissapear' temporarily if I added more fuel?

Now that I think about it, the check engine light did not ever come on. At least not that I can recall seeing. Last year when the drivers side UVCH was bad, the CEL did come on while it was shaking.

Update: now that I think about it, I did run the fuel pretty low last week. I remember it took 26 gallons at fillup, when it usually tops around 24.5 or so.

 

The hutch mod has multiple purposes, but one is the removal of the mixing chamber screens which can cause the flow to become restricted, thus causing low fuel pressure and loss of power. Not saying this is your problem, but it is a possibility.

 

I'll second Alan, sounds like lack of fuel. CPS failure is typically poof and done, UVCH throws a code. Running very low on fuel could suck up some crud and block the screens in the mixing chamber inside the tank. Hutch mod will fix that for good.

But first some questions to help sort out the situation... Does the truck blow a lot of white smoke when running? Can you hear the pump run when waiting for the glow plugs? Get a solid flow of fuel when you open the yellow fuel drain and key over to run?

If the pump is good but the in-tank screens are blocked, putting fuel hose from a container of clean fuel to the suction side of the pump should allow the truck to run normally. Once the fuel is pumped up and the air purged anyhow.

Grab your favorite cold grain-based beverage and spend some quality time with your truck, and let us know how it goes.

 

Morning update:

Thanks to the tips and suggestions received here it seems like I can rule out CPS for now. I have a spare in the glove box, its been there waiting to be put to use for 5 years now.

Looks like its either the UVCH or Fuel. I'm leaning slightly towards fuel, but since I don't have the hutch parts on hand and the kit will take a few days to come in, I'll go ahead and do the passenger side UVCH quarter mod to rule that out for now. If it does turn out to be the UVCH, then I'll wait to do the hutch mod installation in cooler weather.

Speaking of weather, it was 103 yesterday and forecast for 100 today.

This morning I attempted to start to listen to it one more time, and the batteries are worn down from yesterdays cranking attempts. Took them both out, cleaned the posts and connectors, checked the electrolyte and they are charging independently now on the 6a speed.

Went ahead and pulled most of the stuff off the passenger side cover, think I'm ready to hit the bolts on the cover now, but the sun was creeping up over my shade tree, so I'm done for the day. Will hit it at sunrise tomorrow and see if I can knock out the UVCH before I have to leave for work. Have a car I can borrow for tomorrow if I don't get done.

Thanks!

 

I did my drivers side yesterday and it was in the 100's here . While I was cleaning the parts, my tools were in the sun and boy did they get hot.

I buttoned it all up but ran out of time. Going to start her up today and take a test drive.

I have my fingers crossed for you that the uvch will be the fix .
Tim M

 

Sounds like uvch to me too

 

UVCH will set a CEL, fuel issues won't. Worn injectors usually don't either.

How does the fuel filter look? Do you have access to any gauges so you can check fuel pressure?

 

Update: day 2

Checked the fuel filter, it was dirty, but not nasty. There was some light loose sludge residue at the base of the fuel bowl, not a lot. Don't have a fuel pressure gauge handy, but flow seems pretty good after reinstalling the fuel filter and cycling the key on once, then opening the drain again.

The batteries charged for about 5 hours each.

Pulled the passenger valve cover and the UVCH harness looked okay. It might have been a hair loose, but it was not as seperated as the drivers side one was when I did it last year. Went ahead and pushed it together and put the quarter in.

Loosely Closed it up and started. Truck was sluggish to start like the battery was weak, but it fired. Seemed to run okay, a slight miss, but not as bad as before. Only ran it for 20 seconds.

Went ahead and reinstalled all the stuff I took off and tightened up the valve cover, then cleaned up. Went to start the truck and it was DEAD. No battery power dead. Enough for lights and dash stuff, but not enough to crank. Weird. Will take the batteries tonight to Autozone to get them load tested.

Could I have some electrical problem that would be causing these symptoms?

After I get the batteries checked and charged or replaced I will start up and see what happens.

Thanks for all the help and suggestions!

 

Day 3 update:

Got 2 new motorcraft 850 batteries in and started it up. It took a few seconds of cranking before the engine ignited.

Runs pretty good, smooth idle and maybe just a hint of 'shaking' might be my imagination. Did not have time this morning for a full test drive run (and risk it dying on the road), so will do it tonight.

Issue: Started it a few times and it consistently takes 12-16 cranks before the engine ignites. Previously, it started after 3-4 cranks. What would make it take longer to start now?

Idea: There is about 7 gallons of diesel in the tank.... should I add a heavy dose of injector cleaner and take it for a test run? What injector cleaner is good?

 

I added some Howes injector cleaner, alot of it. It started up fine and ran fine on the test drive. Guess it was the uvch after all, unless somehow the 'sludge' worked itself loose from the in-tank fuel screen pickup.

The cranking cycles of 10-13 before engine ignition has dropped to about 6 now. I'll keep an eye on it.

Thanks for your help!