I am writing this to ADD to the search archives for this P0174 code.

I will try and explain as best I can so confusion is limited.

My Dec09 2.1V6 Front Wheel Drive Auto RHD car threw P0174 yesterday. 138000kms total on the thing.
Plugs, upper/lower seals, IMT seal (It only has ONE IMT), MAP seal, throttle body seals (CABLE operated throttle body), and so on at 110000kms.

NO CEL, just a stutter, twice, on hard accel, otherwise ran and drove as sweet as ever.

Scanned it when home, and the P0174 is all that showed.

I applied all the suggestions via the threads in "search", but none mentioned the 2.1V6, they all appeared to be 2.5 and 3.0 related.

This AM, I went looking more carefully:

Battery was at 2.54, ?? borderline, due to too many short stop start runs I suspect. On charge, just because it makes sense.

Sprayed Ether (AKA Start Ya B%%tard down here), and got a HIT at the booster elbow at the rear of the Inlet manifold topside. See the snaps further down.
The nylon "hose" was split where it pushes over the elbow barb. Fixed Aussie style, see the snap.

The 2.1 vac booster pipe assembly has 2 check valves, because of the electric Vac pump this system runs as well as manifold vac. Weird, but thats how it is.

Sprayed the Ether again after the fix, NO reaction anywhere, so I consider it FIXED.




The elbow in question with my "fix"






Culprit to the Right, MAF Left side, with the IMT just in the Left corner.

The snaps are best I can get with age related "shakes", but I reckon you get the idea of the culprit.

The Parts Diagram is TOO large as an image, so I have NOT loaded it. I reckon the item concerned is clearly explained.

 

Old timer truckers in the U.S. Call starter fluid "Tom Cat ****", lol.

Isn't that right side in pic (your problem) the same as 2.5 & 3.0 brake booster manifold hose w/check valve?

 

Dell,

I heard that one years ago, I prefer ours, but that one word sends Forums etc into chaos.

Not sure, but not surprised if it is.
The only 3tr's I have are the X200 S Types, not even close.

The Parts catalogue shows the 2.5 and 4.0 as a simple pipe assembly from the same elbow direct to the booster with 1 check valve, which is "normal".

The 2.1 has a check vale, then a "T" , then another check valve, then to the Vac pump. The "T" spigot goes to the booster, not so normal.

I tried the parts drawing attachment, it stays at full page, not good for here, my computer skills suck, probably age related, like the damn shakes.

That hose I fitted is simply a left over 7.5mm EFI hose, from the V12 days, and with Silicon Spray was a TIGHT fit over the Nylon pipe, and also the barb. Any attempt to remove that hose after 1 hour running and heat soak, failed. That EFI hose has something as a liner, as the same "no remove" happens on the older cars once fuel makes contact, hence the cutting to remove older fuel hoses, after about 2 hours running.

I priced that pipe assembly today, OH dear, not even close to my budget, and then the removal and install, HAHAHA, in my dreams.

I will leave it, I doubt the car even knows or cares, as long as it seals, she be happy.

 

Hi Grant,

You are right......the 2.1 does have a T shaped Nylon joiner from the manifold pipe to the brake booster pipe (6mm to each), with the third barb being 4.5mm that leads down to the auxiliary vacuum pump that is under the left headlight.
Guessing the 2.5 and 3.0 V6 engines with their increased displacement may not need the extra pump present to ensure 100% reliable vacuum to brake servo under any circumstances.

I know this connector well....darn cracked mine when I was fluffing around with changing my spark plugs two months ago.
I ended up picking up a 3 way 6mm Nylon equivalent from REPCO here and had to use a short piece of rubber tubing to interface.
I was successful in heating that hard tubing up with my paint stripper gun on "1" which gave the pipe just enough elasticity to release the barb, but that pipe is really difficult to work with for sure.

I am hunting a bit of a flat spot I can feel when my engine is cold and I start to move off with light throttle. Not there when engine is up to temp.
Idle is smooth and no error codes since I changed all the spark plugs shortly after purchasing the car and going through changing air, oil and fuel filters and trans oils to catch up on it's maintenance.
Cleaned sensors and check for vacuum leaks, scratching my head a bit but haven't given up.
Just repaired my factory radio as it had no display lights, but not entirely happy as they seem dim in comparison to other displays, so will have a second crack at that shortly.

Go the Trans-Tasman bubble!

 

Hi Grant,

Just posting a correction to my last reply.
I spent a bit more time on my my car in the weekend checking for any vacuum leaks in an effort to find a cause on my flat spot - no leaks found as yet.
I did however note that there are two "T" joiners in the vacuum circuit for the 2.1 V6 powered model.
The 6mm x 6mm x 4.5mm white nylon "T" I described previously (which is the first joiner in the circuit) passes vacuum from the manifold downstream towards the brake servo via the 6mm barbs, but the 4.5mm barb is a take-off that connects to the vacuum pump control module that is located beneath the left headlight assembly.
The main vacuum line which continues to the servo is intercepted again by a more substantial "T" joiner (dark grey or black) that provides a branch leading to the actual vacuum pump which is situated between the left strut tower and the battery box.

I checked the integrity of my O-rings on the MAP sensor (and cleaned that sensor) and the O-ring on the IMT solenoid (blue ring which I believe to be the updated part type).
Before I go further into chasing this subtle issue I am running a engine cleaning additive through to clean injectors and combustion chamber, as the prior maintenance on this car looks to have been a bit lacking, so I am in catch up mode still on the various niggles it has.
Does your engine seem to lack bottom end torque and give the occasional cough at low RPM (I seem to get the sense of hesitancy or a slight miss around 1550-1600rpm with very light throttle)?

 

Mark,

Same bloody journey as me.

Tomorrow, body willing, I will use a SMALL amount of JB Weld around that nylon elbow in the manifold, AT the manifold.
I am getting a SMALL, and I mean SMALL Ether hit there, and I am not game enough to try and remove it.
It will get a Brass elbow when the Inlet is next off for sparkers, in 80,000km time, but @ 3500km per year I will be dead, fact.

Mine had the Blue o/ring on that IMT also, but I noted witness mark "gaps" in the bore where the o/ring had appeared not to touch, NO Ether hit at the IMT prior, so I used a TINY smear of RTV on that o./ring, and refitted it, I will not be removing it again, and the Ether is not sensing any leak.

Same with the MAF sensor, checked, smear of RTV, back in place.

I have NO hesitation, and the low end ***** this 2,1 now has after that hose fiasco is amazing, and I come from V12 beasts.

What I did, and do to all these :new fangled" Jags, is clean the face of the Crank Angle Sensor. I did this at the time I did the catch up and the Serp belt (took all damn day that sucker), and that CAS face was grubby.

I put a Nulon Fuel System Cleaner through it when 1st got home with it, and then changed the fuel filter. Oh dear, what a lot of black muck when I cut open that old filter.

Auto trans fluid was awful, Black and stank, so 8 drop and refills later, what a difference, smooth changes, up and down. Its 18months since the last drop and refill, so maybe I should do it again.

Lets know what you find if anything, that way the archives are here when we are gone. This 2.1 is unique to our markets, and maybe Europe, so what we know, we know.

 

Hi Grant,

I am currently running the Nulon Extreme cleaner petrol additive through mine currently, to give it a good purge.
I take on board your nugget and will investigate the location and accessibility of the CAS for giving that some attention. Sounds like a real gem to deal with though.

My 2.1 does seem to lack at the bottom end and seems to get itself organised with reaching a good power band around 3500rpm. There is a noticeable snarl that appears around that time.
Hearing that yours is solid at the low end is making me wonder if I have an issue with my IMT. I did manually operate it to make sure it rotated and noted it has an internal spring return.
So I think I may pull it out again and bench test to verify its servo operation, then refit and measure when it gets activated as I crank up the revs.
I'm smelling a rat.

On the subject of smelling...excuse drawing the long bow.....I dropped my trans fluid a month ago as gear changes were labouring and inconsistent.
Yep, black and stinky too! Looked and smelt like Calcutta sewer water!!
I did three change cycles in half an hour with a short start and quickly cycling through P,R,D between changes while stationary, figuring that I managed to adequately pump the new fluid through the torque converter and refresh the majority of the 7+ litres the trans holds.
Immediate improvement in trans behavior and it improved further over the following week with driving.

This is my daily driver and I am truly enjoying the experience. I don't mind hunting for the gremlins, as long as it is the majority of my time being spent on her.
Front end is a bit clunky, so am going to disconnect sway bar to isolate that, but I think it is likely shocks. It is a 132,000km vehicle so I should expect them to be tired. Top jounce stops are perished, the rears were totally dust and changed 2 months ago when I changed the rear sway bushings.

Will let you know how I get on with my bits and bobs.

 

Mark,

CAS I found without looking as such. Doing the Serp Belt, and asking the Jag Gods for reasons WHY ON EARTH this was done this way, and noticed a sensor, pointing AT the crank pulley, from the cabin side of the timing cover centre line, when peering through that enormous access hole behind the RHF wheel.

My V12 habit kicked in, unplugged that sucker, removed it, cleaned the face, modified the pins, replugged.

That "habit" started with the loooong chase of electrical gremlins in the V12 cars, every "item" was unplugged, cleaned, and the male pins were "bent" ever so slightly off centre, so when the plug was returned, the male pins made 100% firm contact with the female section. Lets it keep it car related, as ladies also frequent these Forums, and I dont know any other way of explaining it, TOOO many V12's with electrical issues does that to you.

The IMT, I did that exact "bending" of the male pins in the IMT socket, just 1mm move to one side, and noted that there was barely any "contact witness marks" on those pins, mmmm, but now with that reshape, I know there is 100% firm contact. I then proceeded around the engine bay and did the same to any plug I could access, but I reckon there are more hidden for that day in the future when I go looking.

Did the MAF, TPS, and some others, took my time, only JUST moved those pins off centre, barely noticeable to the eye, but enough to make that contact true and tight.

My IMT was suspect, and it is spring loaded to what I think is the closed position in our one IMT engines.

Since that work, and the other "catch up" stuff, I have a very reliable, sweet, X Type. Its quiet around the suburbs, and that snarl is there when booted, and runs to Redline easily.