Did I not mention that I already changed the fuel filter? I'm pretty sure the sensor is shot.

 

Ok, some diagnostics have happened.

- Propane applied to all the vacuum lines and connectors while watching STFT for activity. Nothing.
- I noticed a hissing sound emanating from the vicinity of the crank vent valve (this after reading JagV8 who said "hissing is bad"). I pulled the hose off it and plugged the end of it with my gloved finger (my gloves have these cool silicon grip pads on the fingertips), and the hissing stopped. So, I ruled out that length of hose. It is either the valve (which is brand new), or something upstream from that.

I pulled out my directional microphone, ie. a long-handled screwdriver, put it up against my ear and started probing. The loudest hiss seems to be coming from somewhere inboard of the passenger side of the engine, inboard of where the crank vent valve attaches. The LTFT are much higher on the right side (bank 1) than the left side (bank 2), which leads me to think there is an intake or valve cover (both?) leak on the right side somewhere.

So, what gaskets and seals are involved?

- valve cover
- intake runner(s)

It's exceedingly difficult to see down in there to know where to shoot the propane. I'm thinking of using TB cleaner, since I have a nozzle straw for it. I don't believe an intake manifold gasket leak on one side can translate to high LTFT on the other side, so I'm thinking maybe I have several gaskets that are shot.

The saga continues...

Ken

 

I did some TB cleaner probes and got some promising hits, but I can't localize whether it's the cam cover gasket or the intake manifold.

I recorded a video, and the hissing is clearly audible. The audio is in stereo, so you can hear it moving around as I show what I've done. The recording cut out because my phone got too hot (hot engine compartment), but nothing I said after that was relevant anyway. I'm uploading the video to Youtube right now, and I'll link it when it's ready.

Ken

 

 

Right now, the vacuum leak - while it's probably real - is back seat to what I've discovered today:

I replaced the intercooler pump. Unscrewed the giant burp plug on top of the intercooler and topped off the coolant. Turned on the key to the Run position. No IC pump noise. Unscrewed the refill plug again, and verified that there is no fluid flow.

We then bench tested the old IC pump. It works fine. Stuck the inlet down in some water and it moved it with grand vitesse.

Checked the voltage at F36. Good voltage. I then started thinking back to when I replaced the DCCV and how I had great AC and demister functionality during the fall and early winter. Mid-winter, the thing started blowing hot air again and I figured the DCCV or the climate control board failed again. I pulled the computer apart and bench tested it, and it was fine. DCCV must be bad, right? Except that it was brand new. This happened right about the same time that the P2601 started. I found and fixed a couple vacuum leaks (evap purge valve cracked, PCV cracked) as well, which seemed to have gotten the lean codes under control.

So, what I'm feeling is that right now I have an electrical problem that exists somewhere between F36 and the pump. I think that the DCCV is probably fine, and whatever is going on has rendered it inoperative. I even bet the MAF code that I occasionally get, as well as the fuel rail pressure sensor code, are all electrical in nature. The MAF is new and I still got a code from it a few days ago.

So... pull the fuse box? Start checking individual wires in the harness? At least the wiring diagrams list the color codes

Ken

 

Post #2 re harness...

 

Well, I believe we have a winner.




Cooked.



Extra crispy.

 

It's amazing that this connector doesn't have a rubber sealing flange. It's going to get wet; there's a duct in the bumper that goes to a radiator (engine oil cooler?).

I need to figure out how to disassemble the plug without cutting the wires (might not be possible), and I'm going to upgrade it to a more weather-tight connector.

BTW - I'm in the Seattle, WA area - and we get a LOT of rain starting about now, until April or May... Water is a serious problem.

 

Consulting the electrical diagram, the following components are affected: DCCV, IC Pump, all fuel injectors.

It's amazing the car even runs.

 

I noticed that the plug is, in fact, a weather pack connector. The moisture inside was coolant. Unmistakable smell.

A year ago, roughly, I had a coolant leak (one of the hoses up front, next to a belt, swelled up and started impinging on the belt - cutting it and causing a leak). I put in a bottle of UV dye to trace the leak, which tinted the coolant fluorescent green. After I found the leak and fixed it, I drained and refilled the system with the correct orange stuff.

What's the point of this story? The liquid in the connector was greenish orange. It must have seeped in past the seal around this time last year when I had the dye in the system, eventually corroded away three of the 9 pins in that connector, and started a short (both of the DCCV ground wires go through this plug, plus one other ground). With the AC on, the voltage drop across several of the wires going through that connector was excessive. Not enough to blow the fuse, but enough to zap the battery over time.

I drove it around tonight after the repair and it's like a different car

I may still have a vacuum leak, but it needs to relearn trims now that the fuel injectors are all working properly. I'll regroup in a few days and report back.

Cheers,

Ken

 

Ok, it's been a bit over a month. Time for an update.

Not long after these repairs, the car started treating me badly. It would lose power on the highway: no throttle response, basically no power, and I'd have to pull off the road. I was getting - eventually - misfires, and the code that indicates they are bad enough to cause catalyst damage. I started smelling strong gasoline and alcohol fumes (our fuel here is up to 10% ethanol), which finally told me that I had plugs/coil problems. Bank 1 O2 sensor was all over the place - likely from the unburned fuel. I quit driving it (thankfully, I can work from home).

So, I replaced the #6 and #8 coil packs. Now the car runs better than it ever has. I'm not going to clear the codes this time, but let drive cycles do it normally. I got a new phone, and my OBD reader doesn't like it, anyway - so I'm going to get a Bluetooth OBD reader one next week.

The last thing in this series of repairs will probably be a new fuel rail pressure sensor. Hopefully, I didn't destroy the cats on bank 1, or the O2 sensor :/

Ken

 

If fixed, MIL should go off after 3 warm ups (I think that mau mean on the 4th?).

When I changed a front O2 sensor on my STR I also didn't clear the code and the MIL did go off after 3 or 4 drives.

 

The codes caused by the misfire have cleared. However, I still have a few things going on:

- Fuel Pressure Sensor PID reads 0kPa. This throws a code related to the sensor.
- LTFs are way negative now. Cruising at 1500rpm, they are both in the -20% range.
- Coasting downhill, around 1500-1600 rpm, the engine will stumble for a blink, something lights up very quickly in the info center readout, "Restricted Performance" I'm guessing (it's not there long enough for me to read). It feels like maybe a knock sensor stepped in.

I have an EVAP system malfunction somewhere as well, as I am getting every variation of small/large/gross leak warning. This has been going on for a couple years, but I've been ignoring it. I have to pass emissions testing in about 4 months, so I'm trying to get all the repairs done to address the codes

So, after thinking about it for a while, I'm thinking that I may have bad O2 sensors. If the ECM is commanding the LTFs low, but the O2 sensor is lying about the voltage, could that be causing a lean condition that results in a lean misfire - which causes the knock sensor to step in? I'm just looking for a little direction...

Thanks,

Ken

 

Sounds like faults have accumulated. That could make diagnosing and fixing rather hard.

I'd first fix everything that's clearly bad. That's the EVAP. Also whatever fixes the fuel pressure related issue.

O2s are a wear item but both (or all 4) don't go bad at once without some clear cause. Change them if you like but they're probably OK and you may add more trouble (you never know if new ones are good or you may disturb something).

-ve trim means it thinks it's running RICH, not lean...
With various faults it may hardly know what to do about fuel so any trim may result!

 

Update - well after the fact:

The "fix" for the RP on overrun was two things:
- replaced the intercooler pump (it was dead)
- rebuilt the weatherpack plug found at the right front (NA market) of the car. It had gotten coolant in it and shorted. Badly.

The next issue that popped up was the crank, no start problem - which got another thread, but the solution to that was two-fold:
- replaced ***** aftermarket FRP sensor with Jag-branded variety
- replaced battery (it was a Jag battery, but a second, and about 3 years old), to eliminate the raft of sensor gremlins

kr98664 - this should make you happy, +1 for battery being the root of (nearly all) evils.

Ken

 

Phew!

 

P0101 - Have you renewed your air filter lately?

 

Hey Ken! I have the same hissing coming from my jaguar! Did you end up finding the problem and solution to the hissing?