Hi
Just a quick history.1994.5 powerstroke I have owner for a number of years.Previous owner just installed 97 low milage motor.After few miles started to shake gave up and sold it to me cheap.Found on cylinder had both pushrods broken.Removed head etc as lifter retailers were broken.Cylinder bore etc looked perfect,Driven truck 30000 miles since.It has a shake at idle,and worse at 1100 to 1500.Exhaust sound strange also,I presumed injectors but this truck was just a tempory truck untill I found a crew cab which I recently bought.Truck runs perfect down the road,21 miles per Gallon empty.10000lb large trailer about 11-13 mpg.Oil consumption all over the place but no smoke at all exept during warm up.Codes all read fine,sometimes a hi low open on #7 injector.I did injector orings and all injectors are pumping oil and if unplugging one at a time all make a big differance.Should mention comp. test 360-370 all cylinders and starts instantly hot or cold. So here the question,would everyone think it just had injector problem all along or was this something done when 97 motor installed,reason being never really driven when cold out before.Below feezing here now in mornings and noticed when cold no shake,motor runs 1100 cold and the shake only start a little while after the idle comes down.Normaly when warm if I increase rpm up to 1100 has a bad rolling idle or shake,while cold outside and the rpm is high idle perfect.Why would the truck run perfect cold? Should also mention have run a bunch of differant oils which made no differance in performance or drivablity.Figure the injectors have not been the problem all along and something else could be causing it? these injectors are the one that will be sent in the Jim's for my CC project so will be intersting if they are ok
Thanks for any insight

 

I would look at hpop related. Probably an ipr issue. What oil and filter are you running and mileage. Any tunes?

 

No tune,motor should be about 50000mi.,tried rotella,ford,now running lucas,oem filter all without change.only time you'd know something is wrong is at stop light and increase rpm a little or let it idle for more than 30 seconds,that's why I never really workied about it.but before I park it and need parts from it would like to know what the problem was all along.i presumed an injector issue ,

 

Get rid of the Lucas ASAP...

Any chance it's a 5 spd?
The dual mass flywheel does as you describe.

 

Yes 5sp.shake the same with dual mass and single mass,what is wrong with the lucas oil ?

 

You haven't changed the filter

 

Change oil and filter every 4000-5000 mi,change fuel filter every fall,fuel filter has always been clean,oil samples are also fine,other than the shake hot everything is normal other than it uses a lot of oil at times,never any smoke though other than cold normal smoke,the truck has used up to 4q in a 1000 miles and sometime only 1 in 2000 miles,on wekends going to races guys following I asked if they have ever seen smoke and other black up hills pulling the trailer no smoke ever.with that much oil usage though i'd have seen some smoke.boys are sponsored by oil company so not much cost in adding oil regularly ! Been the same with no change for the last 30000 miles.only gets used for going to races on weekends and was never expecting it to last this long.if i had known it was going to be run for 9 years would have long since done injectors as thought that was the problem and didn't want to stick money into it as been searching for a cc with a standard.

 

Oh ok. Keep and eye on the oil and I wouldn't worry about it. Mine has a slight romp after a hard run but will clear up rather quick. Could have a solenoid a hair weak hot compared to the others. I would run it and go. The oil consumption could just be going out the crank case vent into the Turbo if you haven't done the mod. If you ran it a little harder it could have just sucked a little more.

 

I did the crankcase vent mod when i bought it,there is no oil out the hose ,hot in the dark there is visable blue but putting hand over hose not huge pressure as should be expected if it had a lot of blow by past the rings,not really worried as truck will be parked or used as a backup next season just thought would throw this out there and see what the causes of poor hot idle but fine cold.
thanks for the replys

 

So you replaced the stock dual mass with a enw single mass and it didn't change things?

The 7.3 injectors do not like the crap that's in Lucas stuff.
I'm not saying it's a bad treatment overall, it's just not good for our trucks.

 

The dual mass was almost new when I bought the truck,but thought possible it was no good,I welded the flywheel solid and no differance.I don't run lucas additive,I get free jugs of lucas 15w40 magnum oil threw our sponsor.for the first 10000 mile ran rottela,no differance between the two performance wise.this morning below freezing and ran the truck and no shake,15 minutes of idleing around the fields and it ran perfect.It started once again when the truck warmed up.During warm up could run it with no load from idle up to 1500rpm and was perfect smooth.Truck is normaly parked during the cold season so never really noticed that is runs perfect cold.

 

Someone on here had a problem like this and it turned out to be the UVCH(undress valve cover harness) when they got hot the connections would expand and cause it to run rough

 

My truck does the same thing, irritates the crap out of me. Feels like a bad miss. Sometimes are worse then others, Smooth when its cold. I run Rotella. I want to check the injectors and was gonna ask how to go about it. I thought it was my bad dual mass, but I changed that to a single mass. No change. How do you check the injectors? I am gonna check the harnesses as my glow plugs arent working. I just need to know exactly what to check.

 

You can ohm out the injectors and gp's on the vc connections I believe. GP's are outer pins, injectors are inner pins and center pin is a ground. Gp's should ohm at or close to 1ohm each, injectors at or very close to 3.2

 

I probably should have started a new thread but figured we are having the same problem.