Not your typical cam position sensor issue

[Flapjack]

Yep it's dead center, in the valley and harness.

Yup. That's the one I have taped off.

 

[Flapjack]

Update:

So a friend helped me track down what else is wrong with the car... and this one, I can't really explain. Only that it's been a big problem in the past.

Short story, something is up with the TB motor and/or TPS.

Long story, back in 2012, after swapping a stock 5.4 for the built one from MMR, the car wouldn't start. I would get the codes P2101, P2104, and P2110, which basically listed forced limited RPM/power and throttle body motor range issues. The only time I ever touched that particular harness was back in 2008, when I did the original V6 to V8 swap. I could not get the GT500 I had to fit in the normal orientation, so I had to flip it upside-down. The TB motor and TPS harnesses needed to be extended. I soldered and shrink-wrapped like I usually do, and those connections are still good to this day.

After no kidding, a month of troubleshooting, I figured out if I reversed the wires on the TB harness, the car would start and run perfectly. I had absolutely no explanation for it. The wires were correct prior to, but reversing them did the trick... even if it drove my OCD crazy. All was fine until just yesterday.

Outside of the timing and MAF harness issues I've fixed so far, the car really behaved erratically. One day, it would start fine, and idle on its own. Other days, I couldn't keep it running without tapping the gas. Yesterday, it wouldn't run at all. I'd get one big rev when it started, but it would die immediately after.... even if I tapped the gas pedal. It had codes this time... the same as back in 2012: P2101, P2104, and P2110.

That's when we started zeroing in on the TB. We pulled the intake tubing off, and were able to verify it was not able to do its full range test at key on. We pulled it off and hooked it to a small 12v battery I have, and it did the same thing. We reversed the wires, and it opened all the way like it should. So we reinstalled it and switched the wires. Now, it cycled through its range check like it should, but the car still wouldn't run. Same codes, so we checked if the flapper moved with the gas pedal, which it didn't.

This time, I am 100% sure I didn't reverse the wires. Still, I cannot think of a single scenario where the wiring would need change... ever. But twice now, that's gotten the TB to start working again. Today, the wiring is back as it should be on a stock car... but I'm still getting codes.

I ordered a new OEM GT500 TB, which I should hopefully have in a few days. I'm really hoping this is it.

 

[Flapjack]

I am in bizzaro-land. I can't think of how else this is happening.

So, I get the new TB while I'm away on vacation. The night I get home, I literally ran to the garage to swap it out. At first, I just plugged it in and left it on top of the intake so I could see what I did when I turned the key and pressed the gas. The TB flapper opened and closed like it should. However, I instantly got the same codes: P2101, P2104, and P2110, without even starting the car. Looking at the codes in the FSM, P2104 and P2110 are informational DTCs only... meaning they set when another code sets. The code that is actually an indicator of a problem is the P2101. The only possible cause listed is that the wires are crossed.

...and the wires still want to be backwards. I've pinned them out all the way through the harness. They are good. Not shorted, going to the right wires on the PCM, etc, etc. Other than parts of the GT wiring being being extended, the wiring in the car is stock. Until this issue cropped up in 2012, those wires were exactly as they should be: blue to blue and orange to orange.

The only reason we messed with it this time is that my buddy said it didn't sound like the TB was opening correctly during key-on. We pulled the intake tubing off and could see it wasn't cycling open and closed like it should. We "reversed" the wires (which is back to how they should be stock), and the TB would cycle open and closed at key-on like it should, but set the P2101 code at the same time. Also, with the wires reversed to the way they should be, the gas pedal would not open the TB blades.

Tonight, I actually installed the new TB to the intake manifold, reversed the wires again (blue to orange, orange to blue), and turned the key on. The TB did not open/close like it should, but the codes wouldn't set. I tried several times, but the car was DTC-free. I started it up, and it would at least run with some pedal input. Revving the engine up again netted me the original P0340/P0345 cam position sensor codes.

So I'm kinda back to square one, in regards to the cam position sensor codes, but simply cannot ignore the bizarre wiring crap. How is it that I can have the wires reversed and have the TAC/TPS/APP logic all be satisfied.... especially considering the TB doesn't cycle open/closed? If I wire it correctly, the TAC/TPS/APP logic will not let the car run at all.

The ONLY thing I can think of is the PCM... but I actually tried a different one back in 2012 when this reverse wiring issue first reared it's ugly head. Back then, I also replaced the accelerator pedal sensor.

At this point, I'm considering a new PCM and a whole new engine harness. At least then I can rule out a LOT of shit. The only thing that sucks about that is I have to redo the wire tuck at the same time.

Bleh....

 

[Flapjack]

Well, it's been a few days, so I figured I'd give an update, for anyone still following the thread.

The random engine codes continue. The only constants are the P0340 and P0345. Today, I got yet another alternator. I now get these codes as well:

P0191: Fuel Rail Pressure Sensor Performance/Range
P1233: Fuel Pump Driver Module
P0690: ECM / PCM Power Relay Sense Circuit High

Now, some of these may be showing up now because I updated the firmware my X3... which was really, really old. In fact, when I tried to return the car to stock and reflash Lito's latest tune, the X3 hung at 4% when returning to stock, and bricked the tuner and PCM. I had to spend an hour and a half on the phone with SCT recovering everything.

After all was said and done, I flashed back to the working tune, but the car runs the same. Lopes, doesn't want to stay running without constant pedal input, etc. Once in a while, after messing with fuses, relays, etc, the car will run on its own (without pedal input), but is stuck rich, and will eventually shut off because it can't correct the condition.

I'm sure this is something electrical, but I can't seem to figure it out. I have a new PCM, harness, and fusebox on the way.... but I'm worried that even that won't fix it.

 

[ArtQ]

Reload the stock tune. Remove the tune that is in the tuner. Reload the tune from the file that Lito sent you. Reflash the ECU. Had a tune get corrupted once, caused all kind of stupid shit, this fixed it for me.
Also double check you didn't swap your O2 connectors from left to right.

 

[Flapjack]

Reload the stock tune. Remove the tune that is in the tuner. Reload the tune from the file that Lito sent you. Reflash the ECU. Had a tune get corrupted once, caused all kind of stupid shit, this fixed it for me.
Also double check you didn't swap your O2 connectors from left to right.

That's essentially what I tried to do.... though with adding the "return to stock" step, which bricked PCM and X3. SCT had to remote into my PC to fix it. I had to restore the PCM to stock, and wipe the tool. I reloaded Lito's tune and reflashed the car, but it was exactly the same.

I've been able to find a new PCM (05 GT manual), wiring harness (same year), and fuse box. The fuse box came in today, but has the lower tabs broken. I'm a little pissed, but it's no worse than my current one with the broken tabs, lol. The plugs screw into the upper half, so the tabs aren't a big deal.

I'll swap that out tomorrow. If that doesn't work, I'll start pulling the stock harness out. I've been meaning to do a full wire tuck anyway... especially with all the turbo piping. Once it's out, I can inspect every inch of it.

 

[Flapjack]

Another update:
I think we've pretty much ruled out the tune, as Lito has sent several revisions, yet the car doesn't want to run. It'll actually run for a while, until I touch the gas, which causes it to stall immediately.

At this point, I have the new PCM and a tune from Lito, a new fusebox, and a new wiring harness. It cost me a ton of money (over $500 total), but at least I can swap everything out and hopefully rule out electrical issues. I needed a new fusebox and harness anyway, as many clips are broken on various connectors, and the clips on the fusebox are both broken.

I will start pulling the old harness tonight. My plan is to do the wire tuck, but I'll probably just hook up the new harness first, to make sure it's working.

 

[sportinawoody]

I have had a bad 02 ext. throw a lot of these codes. Think it was 14 codes all at Once and the car would barely drive. Dunno why, wires werent ponched or cut but replaced them both just throwing parts at it and problem has been gone for 5 years

 

[Flapjack]

I have had a bad 02 ext. throw a lot of these codes. Think it was 14 codes all at Once and the car would barely drive. Dunno why, wires werent ponched or cut but replaced them both just throwing parts at it and problem has been gone for 5 years

Really? That's insane. I will definitely have to check that.

Do you remember if the P034x codes were included in that list?

 

[Flapjack]

Really? That's insane. I will definitely have to check that.

Do you remember if the P034x codes were included in that list?

I removed the entire harness and checked every single inch of wiring. Everything was fine, to include the O2 wiring.

I'll be installing the new harness hopefully this weekend. Hopefully the problem magically goes away, but I'm going to guess it won't.

 

[1quick08]

Want to follow this,and hope you get this figured out.

 

[sportinawoody]

i honestly dont remember cuz there were sooooo many codes

 

[EGNARO]

i read through this very very briefly ( under a car right now)

i had an issue on a ( mostly stock) 06 gt a buddy of mine had.
car was throwing out tons of codes. swapped the alternator, didn't change it, ended up finding a hairline crack near the drivers side header 02 sensor was giving us cam position codes.
swapped in a set of shorties and issue went away for about 6 months. then he melted the engine #1 terminal in the fuse box and we got 10 other codes. we swapped fuse boxes and he's been good for a year or two. i still think the initial issue was 100% 02 sensor related and the reason he fried the box was his aftermarket ricer underbody lighting

basically i think sportinawoody has a point about checking the 02s because they do some weird shit.

 

[Flapjack]

Want to follow this,and hope you get this figured out.

Thanks for the support.

i honestly dont remember cuz there were sooooo many codes

Lol, I know how that is.

i read through this very very briefly ( under a car right now)

i had an issue on a ( mostly stock) 06 gt a buddy of mine had.
car was throwing out tons of codes. swapped the alternator, didn't change it, ended up finding a hairline crack near the drivers side header 02 sensor was giving us cam position codes.
swapped in a set of shorties and issue went away for about 6 months. then he melted the engine #1 terminal in the fuse box and we got 10 other codes. we swapped fuse boxes and he's been good for a year or two. i still think the initial issue was 100% 02 sensor related and the reason he fried the box was his aftermarket ricer underbody lighting

basically i think sportinawoody has a point about checking the 02s because they do some weird shit.

I've suspected the fuse box as well. Problem is, a replacement from an 05 GT manual doesn't work at all. It must have something to do with the car originally being a V6. What doesn't make sense is that I've been able to run with the V6 fusebox all this time. Maybe I need to find a used V6 fusebox and try that. If I put the GT one in, I can't even get the car to crank. The starter won't even engage.

As for the header, there was a crack on the header itself? How in the world could that cause CPS errors? Not doubting... just baffled. Regarding the fuse #1 terminal melting, are you talking about the underside that plugs in the wire harness 'brick'? I've gone over those a hundred times. They all look good.

 

[EGNARO]

on his car it was actually the fuse area on the top. completely toasted the fuse and melted the box.

thats odd about the v6 fuse box. i do have one i just removed from a car i was planning on using in my gt I'm rebuilding

 

[Flapjack]

Its crazy that it's been over 6 months since I started this thread. I finally got off my ass and found some time to work on the car. A friend of mine came over and helped me pull the engine. Since I needed to get the oil pan to stop leaking (I incorrectly assumed the MMR no-gasket windage tray needed NO gasket sealant.... I assumed wrong, lol), I figured I would go over the timing components.

Long story short, everything looked perfect. The timing was exactly where it should be, though we took it apart and redid it... just in case. This time, I had another set of hands to help, so it's nice to feel good about it being perfect.

I was really hoping for an "ah-ha!" moment... something obvious that could be causing all this, but there was none. The oil looked fantastic, no metal in the oil, etc.

What I am starting to wonder is whether or not those CPS codes were always there. The broken MAF sensor wiring was definitely triggering a CEL, as well as limp mode, but with those issues resolved, I didn't get any more CELs. The codes were definitely there when I pulled them, though.

I'm wondering if those codes could possibly be 'normal' in the case of VCT being 100% removed, as it is with my car. Here's a picture of my heads with the V10 block plates.

Oh... and I also checked the cam trigger "fingers". They don't move a millimeter, so no chance they broke loose or anything.

 

[BruceH]

Only runs if you feather the gas? Sure sounds like a vacuum leak somewhere.

I recently went through a no start condition with my motor after taking the phasers off to put limiters in. Took the front cover off and retimed but still no start. Took it apart again and noticed that the reluctor "fingers" were not the same as they look in the picture from the manual. Somehow I'd managed to break the little roll pins that keep it in place. It happened during the phaser install and everything torqued down correctly. That was my ah ha moment. A new set of phasers fixed it.

Check the finger placement in relation to the R and L marks on the phaser. This is how they should look:



This is how they were:



Hopefully you are having an ah hah moment right now. The R should be between the two fingers and the L should be just about centered with the three finger section.

 

[Flapjack]

Only runs if you feather the gas? Sure sounds like a vacuum leak somewhere.

I recently went through a no start condition with my motor after taking the phasers off to put limiters in. Took the front cover off and retimed but still no start. Took it apart again and noticed that the reluctor "fingers" were not the same as they look in the picture from the manual. Somehow I'd managed to break the little roll pins that keep it in place. It happened during the phaser install and everything torqued down correctly. That was my ah ha moment. A new set of phasers fixed it.

Check the finger placement in relation to the R and L marks on the phaser. This is how they should look:

...
Hopefully you are having an ah hah moment right now. The R should be between the two fingers and the L should be just about centered with the three finger section.

I had checked to see if the fingers moved, and they didn't. I ran out to the garage to see what they looked like... and they seem "ok", though one side is definitely not lined up as perfectly as yours. I don't think it will move, however.

Here are pics of each side (note, I don't have an "R", but instead have a | mark in place of the R):

 

[bujeezus]

sub'd

 

[Flapjack]

** Fixed my images **

I rebuilt my webserver and forgot to resolve the root domain. Just another thing to fix...

I also didn't realize that the forum shrinks the pics down automatically now. No more need to create _thumb files.