hertfordnc

OK, I'm the mechanic.

2001 expedition with 5.4 and 160k miles.

I changed the intake manifold because No. 4 plug well was filling with water. Truck ran perfectly other than this problem. I could pull out the coil pack, clean and the truck would run fine until it filled up again.

The old (OEM) manifold had a visible leak around the gasket and damage to the plastic.

I ordered a new one from amazon (Dorman)

Put everything back together and now it runs like crap. No power.

Idles a bit rough but revs smooth in neutral

But feels like a bad miss when i drive it.

I have spent more time looking over everything than it took to install the manifold.

I checked tohe vac hoses, stray plugs, unplugged connectors, injectors and coil packs.

I don't think there are any vac leaks.

There are no codes.

I did replaced one injector with one from a junkyard but it looked better than the rest.

I would be grateful for any suggestions.

Thanks

Jbrew

What exactly was change , plug type, coil type (you don't have coil packs if it's a 5four). So, need more info. What kind of mechanic was used , - dealership ? Too much missing info to be of any help.

Perhaps some pics of the engine to determine proper connections. Need to help us help you.

hertfordnc

I am the mechanic. there is no one else involved. I guess I was not clear.

Nothing else was changed except the intake.

Thanks for the clarification- they're called coils not coil packs (I'm old)

I could post some pics but really, I think I've accounted for everything (two or three times)

I was hoping there would be some common error known to people who have done major work on this engine.

SHould I run it a while and see if i can get it to throw a code?

hertfordnc

MORE INFORMATION

Fired it up this morning and it ran pretty well for a few minutes. Blasted down the road about a half mile got right up to speed. There was slight miss at lower RPMs

But when i turned around to go back the power was gone.

So we are looking for a problem that shows up after the truck is running a bit.

THe vac lines going to the front on the right side, what do those do?

I feel pretty confident I have all the other vac lines in the right place but where it comes out on the right was a rotted mess of electrical tape so i refreshed it as best I could.

I'm assuming one line goes to control HVAC under the dash and the other goes to some environmental gizmo. But I'm thinking it can't be that critical to the engine running right.

Jbrew

Check the EGR valve. Sounds like it's not shutting all the way. Once the vehicle gets up to cruising speeds, the valve opens then shuts. If it isn't shutting all the way, it can run the way your referring to. Could have knocked a piece of carbon loose from the valve while working on it that's keeping it open. This won't always kick up a DTC.

You also could have melted a cat shut from a misfire.

Bad gas ? How is your fuel pressure ?

Other than that, your back to ignition.

I've had coils go after re-positioning them on different cylinders.

A smart phone can tell you which cylinder is misfiring via live data, -techs use that little trick.

Which side are you calling the right side ? Right side is passenger side, -Left is drivers..right? What color vac lines ?

hertfordnc

The cars right- passenger side.

THanks. this is very helpful.

hertfordnc

You do mean a smart phone and an OBD scanner, right? I'm using TOrque on my phone but my scanner just died. It's had a long life.

Got any troubleshooting tips? If it is the EGR then would disconnecting th EGR tell me something ?

THanks

Jbrew

If you disconnect the green line, that would eliminate and EVR problem if there is no change. If you loosen the EGR, slide a plate between the the port to the elbow, then tighten it back up and go for a drive. No change would eliminate an EGR problem.

Jbrew

If you trying to pinpoint a misfiring cylinder, a smart phone and live date with the torque app wiull finger the cylinder.

Jbrew

Right,

Well you never know.