IAC, TPS, Vacuum Leak?

[SkyJumper]

Well if you are getting a P1506, the IAC is having an issue and is most likely causing the rich smell. Sometimes the IAC can get a small carbon buildup on the shaft that would prohibit the full closure of the shaft, some carbon gets wedged and wont allow it to close fully. I would try cleaning it again. If no go, then I would purchase a new one. But I have also experienced a clogged injector cause IAC code P1506 to go off. IAC are relatively inexpensive to buy and takes all of 5 minutes if you are slow to take off and replace. But I diffinately would not just keep throwing new parts at it without doing further tesing.


When you cleaned it before, did you properly clear the code before you restarted it back up? And how are you clearing the codes?

 

[gavin]

well I found the problem
when I spray the hard vacuum lines, that go back to the EGR valve, where they ride along the side of the upper intake, RPMs increase.

which means... either a leak in a hardline (doubtful), or my upper intake gasket

how.. erm... safe is it to drive around with the MAF disconnected and an intake leak?
it's failing to stay running now with the MAF connected... and I can't really miss work tomorrow...

 

[SkyJumper]

Well like I said in the first few posts, take and spray all around the intake untill you hear the area of concern. You may get away for the short term and pin point it and you a hot temp silocone to the leaking seam line on the intake. Let it sit for awhile before you attempt to start up. This will work for the short term and allow you to take the intake off and replace the gasket on the intake.

 

[SkyJumper]

You can also use a small diameter hose and cut yourself 1 ft length and hold to your ear and run the other end around the intake seam line and listen for the air.

 

[Turdle]

I think you should be ok if you baby it. How far you have to go?

those hard lines get brittle. One might be disconnected. red to fuel regulator-green to egr valve white is source.

 

[SkyJumper]

The VAC lines along the intake do get brittle and the rubber pigtail connectors also crack and break.

 

[gavin]

I think you should be ok if you baby it. How far you have to go?

those hard lines get brittle. One might be disconnected. red to fuel regulator-green to egr valve white is source.

The VAC lines along the intake do get brittle and the rubber pigtail connectors also crack and break.

ok, maybe I'll just start there.
But that's definitely the area of concern, no doubt about it.
as for the failing to run, that would be because I forgot to reconnect the IAC. I had disconnected it to see how it would behave.
Although it was a good thing, because I had sprayed that spot before and noticed nothing, but it was already idling at ~2000RPM.

It's only about 4 miles to work. Usually takes about 15 minutes. Driving in general isn't affected even with the MAF, it's just the shifting is off and idle is horrible.

Hopefully I can get Friday off to tackle this early. I can certainly use a wrench, but I have yet to delve in to any engine work.

I s'pose it's about time for a gasket to go with >188k miles. Or, at least require more engine work than plugs and wires.

 

[SkyJumper]

Well wish I was in your neck of the woods as I love the Alaska surroundings. I then I would head over and help ya. But keep us informed of your progress on it and see what we can do on here to get it right.

 

[gavin]

Well wish I was in your neck of the woods as I love the Alaska surroundings. I then I would head over and help ya. But keep us informed of your progress on it and see what we can do on here to get it right.

oh definitely will. Hopefully it will be easy/smooth.

doesn't look like there are is a sticky for a 5.0 intake gasket how-to.
s'pose I just may have to make sure and document it :

 

[SkyJumper]

pretty straight forward. Just while you are working and the intake is off, keep the area around you clean and make sure you drop nothing down in the intake valley. I hate intake gremlins after everything is put back together, and you go looking for the 12 mm socket and damn, start it up and wala, that is where it went.

 

[Turdle]

oh definitely will. Hopefully it will be easy/smooth.

doesn't look like there are is a sticky for a 5.0 intake gasket how-to.
s'pose I just may have to make sure and document it :

You might follow mountaineergreen's intake spacer install. It will be similar-just less parts.

 

[gavin]

pretty straight forward. Just while you are working and the intake is off, keep the area around you clean and make sure you drop nothing down in the intake valley. I hate intake gremlins after everything is put back together, and you go looking for the 12 mm socket and damn, start it up and wala, that is where it went.

yeah, that's what I'm afraid of lol

You might follow mountaineergreen's intake spacer install. It will be similar-just less parts.

ahhhh, forgot about that one.
will have to check it out.

 

[SkyJumper]

Find anything out today?

 

[gavin]

nope... stopped by the parts store on my way home. They don't have the gasket kit in stock, but have 'em at the warehouse.
Will pick it up tomorrow.

Couldn't get tomorrow off from work, since my co-worker I back up already had planned leave.

Will start the tear-down tomorrow afternoon.

still runs great other than high idle lol.

ah, gotta try and clean the engine compartment out a bit too; it's quite dirty.
spray it down with some simple green then rinse? when the engine has cooled off, of course.

also looked through my FSM, and it doesn't talk about having to remove the coil packs to remove the intake manifold. Doesn't appear to be a difficult job, just tedious.

 

[SkyJumper]

Best lesson ever learned for me was on doing a tear down is get yourself a couple of boxes of 1 gallon freezer zip lock bags, black permanent marker, and a camera, put all bolts in a baggy and label the bags, and take pictures as you go from opening the hood to completing the tear down. Helps when you are unsure where something goes or how it went around and thru to get where it needs to. Close ups and all around shots are the best, once you finish one task, stop take new pics. But marking the zip lock bags with the contents is a big plus.

 

[gavin]

Best lesson ever learned for me was on doing a tear down is get yourself a couple of boxes of 1 gallon freezer zip lock bags, black permanent marker, and a camera, put all bolts in a baggy and label the bags, and take pictures as you go from opening the hood to completing the tear down. Helps when you are unsure where something goes or how it went around and thru to get where it needs to. Close ups and all around shots are the best, once you finish one task, stop take new pics. But marking the zip lock bags with the contents is a big plus.

definitely a good idea.
less chance of ending up with "spare" parts :

 

[gavin]

going much smoother than planned.
1.5 hrs to get the manifold off.

Question (next pic); what hose goes here? I did not remove it, but once I was able to start pulling the manifold up I looked and did not see a hose. Where does this one go? The other end is the T and PCV.

Crack in the gasket? Possible cause?

I know the engine won't be shiny clean, but does this seem like an excessive amount of carbon build-up? Considering the truck has >188k miles on it.

Also, Fel-Pro are the most recommended brand of gaskets, correct?

Also found the source of the exhaust tick. Gonna try and "repair" it with some steel-epoxy putty I have left.

 

[gavin]

Ok, so this has to be and have been the problem.
Got the manifold reinstalled with new gasket, bolts torqued down properly, and all vac lines hooked back up along with PCV.

There are no hoses left to connect to the fitting outlined.
What goes here?!
I never removed a hose from this spot, it did not get pulled loose when I was pulling the manifold off, and there are no loose hoses left!

This is the rear driver's side.

 

[Turdle]

Put a cap on it--
some have caps there, some have another "t" fitting which splits it again into the pcv--brake booster line. Your original backfire probably blew it off. That was the source of the hiss I bet--

 

[Turdle]

OK the crak in the upper plennum combined with the cracked egr tube cold have definitely cause an intake backfire upon start up. This could easily blow the cap off, making the leak worse.


You really need to get a new egr tube. any kind of steel putty will melt, it gets about 1100 degrees there.