What's missing??

Rocko

Test Drive
Location
Pittsburgh
Was looking the engine bay over yesterday and found these open plugs. Anybody have any idea what they go to? Also looks like something is missing on the valve cover.
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Muadeeb

Bastard Admin from Hell
Admin
Location
Dallas
Not sure what's missing in the 1st two pics, but on the valve cover, that's where the connectors for the O2 sensors go. If my head clears up later, I may be able to dig up what plugs into those connectors.

Also, check my engine bay overview. I may have something tagged in there you don't have.

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Rocko

Test Drive
Location
Pittsburgh
Ok, had a little time to look at some stuff today. Stopped at Advanced Auto on the way to the dealer and had them pull the codes for me.

P0325 Knock sensor circ-B1
P0505 IACV/AAC VLV/CRC
P0300 Multi Cyl Misfire

After which, either the reader does it automatically or he did it, but it cleared all the codes and turned the light off. Left there and stopped for gas and filled up on regular, started up and drove flawlessly to the dealer. Didnt miss, putter, no light, nothing. Figured maybe I got some bad gas or something so I told them I would keep it over the weekend and see how it acted with the new gas.
On the way home it started with the missing, puttering, no acceleration occasionally. But if you floor it, it will act like nothings wrong and take off just fine. The CEL blinked a few times but has not stayed on.
Ive referenced the FSM and am going to see whats up with the idle air control valve tomorrow. I did also reference the engine bay write up pics and see whats going on with the valve cover, unfortunately someone cut the o2 sensor wires too short and i cant remount them. As for the open plugs..... its still a mystery. Im hoping that maybe they go to this IACV?? Maybe why its not working?
 

Rocko

Test Drive
Location
Pittsburgh
Im really impressed with this little V-6 when its running right. I had a Full size chevy 4x4 with a 350 and it wasnt as peppy as this 3.3.
 

Muadeeb

Bastard Admin from Hell
Admin
Location
Dallas
IACV is located _under_ the upper intake, so way out of position for those connectors. Haven't been clear headed enough to research the possibilities.
 

Rocko

Test Drive
Location
Pittsburgh
IACV is located _under_ the upper intake, so way out of position for those connectors. Haven't been clear headed enough to research the possibilities.

If I remember correctly the open loom I found ran up from the drivers side of the firewall, around the back of the intake and was just laying on the top of the motor. Im being optimistic. lol

Thanks for your help tho Muadeed!
 

Silver dude

Sliders
Founding Member
Tried to find the wires in my own engine compartment and failed mine are all sheathed wires rather then split loom like that to the ends.

Connectors clip into the brackets on the valve cover.

Appears to be quite a bit of aftermarket wiring in your engine compartment namely that red wire that is in all the pictures. Especially, that last photo which makes the red wire appear as though it was spliced or something or is that the aftermarket O2 sensor.

IMO the codes you have are all related except the IACV.

Knock sensor code= because the engine was actually knocking do to a misfire.

Misfire code= likely the engine misfired

IACV= I'm not real sure on that one its just a valve that meters the throttle body air bypass to adjust idle if its cold it will bump the idle up to warm up faster. Odd that it would be tied to the rest of the codes.


Have you done a tune up on the ignition yet? plugs, wires, cap and rotor would be a good place to start. The early X's are known for distributor failure.

Has the engine been idling or running rough?
 

drbandkgb

Titan Swapped / SAS'd
Founding Member
IACV is a pain in the but.. I replaced mine..
You will need a new intake gasket, and since you are that deep you should replace your Valve cover gaskets too.

I will still randomly get a p505 when I use my front defroster..
 

Rocko

Test Drive
Location
Pittsburgh
Tried to find the wires in my own engine compartment and failed mine are all sheathed wires rather then split loom like that to the ends.

Connectors clip into the brackets on the valve cover.

Appears to be quite a bit of aftermarket wiring in your engine compartment namely that red wire that is in all the pictures. Especially, that last photo which makes the red wire appear as though it was spliced or something or is that the aftermarket O2 sensor.

IMO the codes you have are all related except the IACV.

Knock sensor code= because the engine was actually knocking do to a misfire.

Misfire code= likely the engine misfired

IACV= I'm not real sure on that one its just a valve that meters the throttle body air bypass to adjust idle if its cold it will bump the idle up to warm up faster. Odd that it would be tied to the rest of the codes.


Have you done a tune up on the ignition yet? plugs, wires, cap and rotor would be a good place to start. The early X's are known for distributor failure.

Has the engine been idling or running rough?

The red wires are from the o2 sensors. I want to clean all that up, whoever did it, did a nasty job, but Im not getting any o2 CEL codes so Im assuming they are all working.

The engine has been running like crap, missing, sputtering. Sometimes it stops all that and runs like a dream. Even when its misfiring really bad, if I floor it, it will act like nothing is wrong at all and take right off. I have replaced the cap and rotor and checked for shaft play, nothing front to back but maybe 1mm up and down.
I have the new plugs and wires, just waiting to have compressor access to blow off the top of the motor.

As for the missing plugs, the first plug I am holding in the pic is blue, just like the one I found going into the main loom that runs from the front to back of the intake. But there is already a plug plugged into that one.....??
I still havent found anything that the other 3 go to.

IACV is a pain in the but.. I replaced mine..
You will need a new intake gasket, and since you are that deep you should replace your Valve cover gaskets too.

I will still randomly get a p505 when I use my front defroster..

I saw where it was, and Im not looking forward to it. How hard is pulling the intake? Its just the upper intake right?

Thanks for looking guys!
 
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Muadeeb

Bastard Admin from Hell
Admin
Location
Dallas
I'm starting to get clear headed enough to read back through this...



The 2001 didn't have a SC option; it was only available in 2002-2004. Also, the truck would have a myriad of body style changes such as a bulbous hood to indicate that it's from that time period. I'm starting to think that the previous owner did so much mucking about that maybe the O2 sensors are backwards or something. They're close enough to be in spec, but are telling the computer to trim the fuel on the wrong bank.

Dubious wiring (those red ones) I'm wary of with no documentation. I'm also curious as to why the O2 connectors are so short...

<looming>
The factory looming has 3 penetrations in the firewall : Driver side near the fender, passenger side near the fender, nearish the center for the engine. The engine harness is the main trunk line in your pictures that runs along the upper intake. There's 1 connector, gray, that breaks off nearer the start of the run and connects down to the transmission and transfer case. I can't quite tell the color of the connector in your hand.

<the Trio>
Do you have a working window wiper? I'm still not sure on this one, but there are two connectors back there, but I don't think the colors match. The other one may go to a factory security horn; black connector with only 1 wire in it.

<intake>
Pulling the upper intake isn't that hard, just really frustrating at times. Be prepared for the captive socket bolts to strip. When they do, grab a deep 12mm and beat the tar out of it to wedge it over the bolt head. You should be able to drive the bolt out with it on like that. End result:
intake_bolt.jpg

There are also two coolant lines at the back. Save yourself some headache and cut them. I spent way too long trying to undo ONE of the hose clamps back there.

I'll keep digging.
 

Rocko

Test Drive
Location
Pittsburgh
A missing factory horn might make sense since it doesn't beep when I lock up. The wipers work fine. Everything seems to work fine except evidently the IACV. And potentially the o2 system since the symptoms I'm having with running and missing seem to stem from them.



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Muadeeb

Bastard Admin from Hell
Admin
Location
Dallas
The horn beep can be disabled by pressing both the lock and unlock buttons on the fob for 2 seconds. Do again to reenable.

At this point, I would love an afternoon to crawl over that truck.
 

Rocko

Test Drive
Location
Pittsburgh
Would a bad ground possibly be a culprit? I found a broken ground strap on the pass side fender. Looks like it might have grounded to an exhaust or valve cover bolt?


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Muadeeb

Bastard Admin from Hell
Admin
Location
Dallas
It can cause problems. That particular one went to the exhaust to help provide ground for the O2 sensors. If you have some spare 18 awg wire, just run a new one.
 

Rocko

Test Drive
Location
Pittsburgh
It can cause problems. That particular one went to the exhaust to help provide ground for the O2 sensors. If you have some spare 18 awg wire, just run a new one.

Ugh ok! I will get to that first thing tomorrow. I hate following a shoddy mechanic! I'll have it in shape before too long. Glad your feeling better!



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Rocko

Test Drive
Location
Pittsburgh
Update,

Got a chance to look at some wiring, although I didnt think to take pics. Any way, tracked down the spit and sputter to the O2 Sensors. The mechanic that installed the engine had Bank 1 and Bank 2 Front switched. Of course thats going to screw everything up. Switched the plugs and havent (fingers crossed) had a problem since. I did get all the plugs mounted back to the valve cover. Im still kind of disappointed that it doesnt really get any better mileage than my old truck. :( But oh well, its still going to be a fun toy/grocery getter/kid hauler/etc. I wasnt comfortable taking it back to the mechanic at the lot I got it from, so I just had him order me that new distributor anyway. I told him I would rather install it myself. He didnt argue. Should have that by next week. Noticed the valve cover gasket leaking and will get that taken care of next. Whats the best gasket out there? I want to hear some opinions.

Took the mud flaps off. Im going to have to leave those factory steps for now. My 4 year old can actually crawl up in it now, but without them he's not going to be able to do anything after I do some lifting. Havent had a chance to get it up and do the PML. Maybe after christmas.
 
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