Ok, I pulled a vacuum while my truck was running and the idle shot way up, so that's normal. The large hose on the air pump air cleaner that doesn't go to the air pump is just a hole to the atmosphere to draw in air. Mine has a hose that runs through the inner fender to draw in cooler air. The bypass hose missing from the air pump air cleaner looks like an area to vent the vacuum, mine doesn't have it and doesn't look like it is required or important. I can't make out the other small red marks in your diagram but if the valves are missing then the thermactor system isn't working right. If the vacuum hoses that are supposed to run to the valves aren't capped off then the vacuum leak won't help the way the truck runs. While I have removed most of the thermactor system on my truck I left the valves in place so the solenoids would work correctly and there would be no leaks.

 

I've been under the truck trying to see what the hell is behind the back of the motor... I found the valve, but like you said, there is no place for a hose to connect to it anyway. All of the vac lines are in place, with good fit. It looks complete after all, and I now have the solenoid connected right. All of the 'plumbing' looks to be good (no rust, cracks, etc. that I can see). The other red marks overflowed when I tried to color the arrows in MS Paint - not actually missing.

Looks like it's just missing an air intake hose to that air filter, that really doesn't matter anyway. The filter is definitely sucking air in.

I did find another vacuum leak, though... The cruise control has a vac line with a T in it, going to the manifold and to another canister on the drivers fender. The connector at the canister had a hole in it. I don't have another connector, so I capped it just for the sake of seeing what it would do.

After running the sea foam through it earlier, I had to let it run for awhile to blow all the junk out of the intake. It sure seemed to have more power sitting in the driveway - revving the throttle actually twisted the truck sideways instead of sputtering up to a higher rpm.

...of course, my wife is at a work event, and I have all 3 kids at home, so I can't really get it out to drive it tonight without loading up all the kids (who don't all fit in a truck very well).

 

The large hoses off the diverter valve go to the catalytic converter and one goes to the exhaust manifolds. The one for the exhaust manifolds tees into two and then connect to the manifold before it bolts to the pipe. It may even have a pipe that separates into 4 ports close to the head, but I think yours has one large connection into each manifold. My 6 cylinder has a pipe that separates into 6 and is threaded directly into the head. This is why I removed mine, when I changed the head the pipe got destroyed when I tried to unscrew the ports. 6 brass plugs and it was all fixed.

 

Yeah - you're right on. Mine is pretty close to the diagram. The pipe splits in two, check valve, into the head. There's another pipe running to the exhaust, etc.

I think that was a wild goose chase (although the vac line disconnected might have been an issue).

Let's clear the slate here, and try to rethink this - pretend that I'm brand new, this is my first post, and I post that my truck is chugging heavily at low rpm, better at higher rpm, idles low and sometimes dies at a full stop while in gear, and has no power. Aside from pulling codes, what would be the first things to cross your mind?

 

With fuel injected my first thought is always pulling codes. My whole diagnosis depends on the codes, or lack of codes.

 

Grrr... Let's say there are no codes. What would you suspect first that wouldn't cause a code?

 

Tune up items, distributor cap, rotor, plugs, wires, etc.

 

The cap/rotor are the only tune-up items yet to replace - possibly the issue?

I don't have a timing light to check timing... but could get one if necessary. Don't know what to do with it, but the chilton book has a step-by-step.

What do you think about fuel pressure? The tank/pump/sender/wiring harness are all new - maybe a bad regulator? Clogged injector? Hopefully the sea foam in the gas tank will cure any clogs if they exist. I do plan on getting a fuel pressure guage to see what's going on there, because I'd like to know for sure.

TPS or ECT? Seems like in my 'quest' for info recently, a lot of online info points to these going bad and causing performance issues. No codes for these, but worth checking voltages and knowing for sure. I also noticed that the throttle set screw is all chewed up (like someone has tried to turn it with pliers or something) - maybe it's out of proper adjustment? I found a good how-to online that explains how to use a volt meter to get the set screw and TPS back in sink.

Still stuck with EGR issues? I guess it's possible (considering that the code says so) but I just can't believe it. I almost think that there has to be more to it, and it's probably so simple or common that I'll feel really dumb when I (we) figure it out...

Obviously, I guess it could be something internal (related to the ticking sound). Do you think that the source of the ticking could be bad enough to cause all the performance issues?

I guess there could be a million places to look. And like you said, the codes are the logical starting point, but does anything else wave a red flag?

 

I just realized something...

117 posts
1200 views
$370 worth of parts
6 weeks worth of frustration
1 neighbor who works for Ford and has absolutely no mechanical ability

And I'm not a bit closer to a solution than I was 6 weeks ago.

There has to be some humor in all that - but I can't find it

 

Unfortunately you can pick any sensor on the truck and it could sound like the cause. TPS, you have removed it so it could be out of adjustment and the wires are in bad condition. ECT, another important sensor that would cause a bad running condition because the computer won't know when to go closed loop. Oxygen sensor, the computer won't know how well it's adjusting the fuel mixture. IAC, poor idle and depending on how it's stuck could affect driving performance. MAP, no vacuum sensed so the computer has no idea of the load on the engine. Knock sensor, knock not sensed would prevent correcting timing adjustments. Blah blah blah, am I helping?
A quick test for the regulator is to pull the vacuum line from it and if idle speed picks up it is working. Your problem has been driving me crazy too. I'm trying to think what else may be wrong if the EGR code is trumping a different sensor and not allowing a code for it, like MAYBE the oxygen sensor because the computer may think the EGR is causing a bad air/fuel ratio instead of the oxygen sensor. Then instead it guesses on the A/F instead of reading sensor input.