So my '97 vert has been acting up lately.

An occasionally P0441 code (see screenshot below, but it's "EVAP system incorrect purge flow") became a near constant one as fall has cooled down, along with a common fuel smell. I suspected a failed purge valve, and was pricing out replacements, but couldn't get a consistent part number from the parts sites. I saw LJA1515AA, LJB1515AB and LJG1515AG mentioned on the forums and available from retailers. To make things more complicated, the LJA..AA is literally half the price of the other two. Are these all parts for the same component/role? All the descriptions I had found described a purge valve assembly inside the drivers' (LH) wheel well, but then I found a LJA1515AA attached to the LH bulkhead extension right at the top while I was doing the tensioner job last month Is this the same one, or are there two different similar purge valves on a '97?

To complicate matters, I discovered the AA in my engine bay had what appeared to be a snapped hose nipple on the bottom of the assembly that had been hastily plugged/mended with hot glue at some point in the past. As it wasn't plugging the hole, I attempted to add some RTV sealant I had handy, but that didn't make anything better. So now it became a higher priority to fix/replace.

To start with, does anyone know the correct part to replace the broken AA in my engine bay? Get another AA for $35, or an AB/AG for ~~$75-95?

Next, the symptoms I've been fighting, and I'm not sure if they could (theoretically) be connected. I'm not terribly experienced with vacuum/evap/fuel system issues, and I think it's one of the above.

- For a while when cold it seemed to have a really hard time catching, either not catching at all on the first ~5 second crank, or catching at an extremely low RPM and then coughing until it surged up to 500ish RPM. So I started (when cold) turning the key to prime the fuel pump, letting it run, then repeating (up to 3x) before cranking. That seemed to almost fix the cranking issue (I also replaced the battery and topped off the oil while doing this). I suspect the fuel pump is either slow or dying...the one time I've had a gauge on the rail, it only read ~25psi after a 2second pump run. I suspect it'd read higher if I let the pump run its course (like I normally do now in operation), but I haven't had a chance to check.

- Just this week I started having issues with it stalling (almost stalling) when hot at idle+brake (like braking hard for a stop sign, at which point it seems to not slow down much until the torque converter starts to disengage, at which point it dips below 500 RPM like it's stalling unless I let up on the brake slightly.) It actually did stall out once, I had run it at highway speeds for a while, put it in park when I reached the airport to let my passenger load their bags, then shifted into reverse for a moment before pulling out, and it stalled right out, with 'Engine Stall' on the display. It started right back up fine, but by the time I got a reader on it a couple hours and starts later (mine was on the fritz, or that would have been a matter of seconds!) the codes had cleared, or there never was one. It mostly seems/has seemed to run fine and shift fine, I think, particularly above 1500 RPM, but it seems to burn a lot of fuel and not run too happily at 12-1500 RPM. Might this be purely a transmission issue (eek) or something else?

- I also happen to know that I have cracks/potential bad seals on both breather hoses, so they're due for replacement. Not sure if they could be affecting it that badly. I also overfilled the gas tank last week, I think :/ but that was after the stall (albeit not the later stop-sign issues). And it's overdue for an oil change, ah well.

Anyone have any ideas about what I'm debugging here? I don't want to start throwing parts at things without reason, but I'm a little out of my depth with these systems. I definitely want to replace the broken purge valve pronto, if I can figure out what part to order! I'm trying to recalibrate my expectations and my hearing for this car as we enter fall...hard to know whether small things are normal or are failures, so early in my ownership. :/

 

You've listed several issues in one thread, it may be more convenient to start one for each for as the thread grows it won't bounce around topics, that said:
Usually AA/AB etc are revision numbers, you can contact SNG Barrett (sponsor) and they can help you. I do not believe there are 2 purge valves.

You may want to start with the fuel filter for idle issues, I also think the early models have a fuel regulator in the engine compartment, this maybe bad and of course fix the seals.. You'll need to methodically work through one item at a time.

 

@jamdmyers thank you. I'll leave this thread for the purge valve question, and move my stalling issues to a separate thread. For the record, the previous owner replaced the fuel filter just a couple years and a few thousand miles ago. :/ I patched up the hoses and it's running slightly better, but still having problems with brake+stop conditions.

 

If I recall correctly the AB replaces the AA. You can call jagbits.com to verify. See this link http://www.jagbits.com/product/LJB1515AB.html

As for the fuel pump the fuel pressure should be well over 35psi. I suggest using another gauge and test it again.

As for the transmission not disengaging do you know if the fluid and filter were ever changed?

 

@Gus thanks.

I went ahead and ordered an AA on the advice of SNG Barratts. Either way, if it works I'm ahead of the current game. Looking at photos of replacement parts online, I finally figured out what the broken hose connection on my purge valve was for--it was for the vacuum hose! (however, I checked, the hose had been properly terminated by a previous owner, so that's not the leak...)

I was planning to check fuel pressure tonight but ran out of sunlight. Will try again in the morning. May try to pull the intake and clean the throttle body before work, too.

And I'm pretty sure the fluid and filter haven't been changed, though there's a huge gap in the service history between ~55k and 98k when lots of things may have (and some seem to have) been done. Been reading up on threads and trying to decide if I feel like tackling it or not...there is a dedicated transmission shop just a couple miles away, too...I've never done anything on a transmission before.

 

Another way of cleaning the throttle body.

Link JagRepair.com - Jaguar Repair Information Resource

 

Interesting approach. If I had a spare intake I'd try it...as it is my current one is kindof ratty, and I don't want to introduce another potential leak...

 

Well it has worked for me for several years.

 

Thanks, Gus. I went ahead and pulled it this morning and cleaned it by hand, and reset the ECU and it seems better now than it did yesterday. No stalling, but there's still a huge drop in RPMs when the trans attempts to unlock at a stop. And a slight surge after as it returns to idle.

 

@Gus after hearing some noises that I thought were the transmission, I took it to a local transmission shop. They gave the trans a clean bill of health, drove it, said the pressure looked fine, and refused to charge me anything for diagnosis.

I got the (same) gauge back on the fuel rail and tested with 5sec with the key in On position. 25psi after the first try, and then 42 after the second...I guess I should be looking at fuel system debugging. If that's consistent then I'd guess the system's running lean...and maybe dropping lower (due to lower voltage) when the car's barely ticking over? LT fuel trims are positive, but not large: 3-4%.

 

If the fuel pressure is not consistent then replace the fuel filter and if that does not fix the problem replace the pump.

 

That's exactly what I was thinking. Many thanks.