Since the weather has dropped to teens and lower the last couple days, my car is ticking like crazy, yet predictably.

First, the ticking I speak of is tucked just above the fender under the cover, loudest heard at the hinges of the driver's door. The video doesn't do the ticking justice. While driving, I hear the ticking even over the radio at a moderate level...very irritating. Forgot to mention, smells like fuel in the cabin also...coincidence?



It does cycle, at a constant speed, I would estimate 30 seconds on, 5 seconds off. When it occurs, I can cause it to silence by releasing the accelerator, therefore I assume it is fuel system related. There is no change in engine idle or performance, just the damned tick tick tick, same repetitive interval, no matter the engine speed. Listening on the fuel rail, the firewall and center of the rail on the driver side IS significantly louder, if that makes a difference.

Can anyone tell me what is the cause, and remedy? I am easily annoyed. I do have the AE obdII also, so can check something obscure if necessary in real time. If I knew what to look for in the ECM area, when this component starts clickin...should be easy to find...but what?

 

Location + ticking + fuel smell = canister purge valve

TICKING NOISE FROM LEFT SIDE FOOTWELL - EVAP CANISTER PURGE
VALVE - REPAIR PROCEDURE - REVISED
Vehicle: 2003 Jaguar XK8 4.2 V8 GAS

Thought you had yours replaced(?).

ECM area?

 

I had it replaced in 2008, part num LJC1525AC on my invoice (LJB1525AA on the parts diagram) I assume the cold weather affected its performance...I may try to find a procedure to R&R it myself. Tom, did you try to post a link also?

 

No, no link. I only had the AllData snapshot and just posted the heading.

Bob, you got that TSB?

 

It appears my first reply was wrong, it was documented correctly on the invoice Tom, LJC 1525 is the CCV, which was replaced. But the purge control valve which you mentioned by the left front wheel, is still the original. The EPC says its $230 part, but online through our forum sponsor, looks to be around $70.



Now, for the R&R, checked the JTIS,









Looks pretty straight forward, however, my car falls into the pre 36752 category, so what happens if the ECM software isn't 'updated'? Oh boy...

 

If you would post the TSB as an attachment then I could put it in my library.

 

Its just the R&R procedure from the JTIS above...you want that?

 

No, I thought you had the TSB.

 

Here is the TSB
and the amended version


bob gauff

 

bob, thanks, that TSB explains my situation precisely. It has reduced in volume, back to its normal level since the weather went back up, and my speeds are no longer consistently 20 mph on the icey roads here. I'm planning for the part change though before next winter.

 

Soooo... what happens if I leave the electrical connector disconnected? I'm still troubleshooting my fuel system problem and I'm wondering if the canister purge valve is allowing air into the fuel system after it's shut down. I'd like to leave the electrical connector to the canister purge valve disconnected for a day to see what happens. Am I going to screw anything up?

 

Pretty sure you will set a fault code. I think you might smell some fuel vapor from the vent at the right rear wheel and/or at the valve.

This is a guess, but I think if you do it for an extended period you can saturate the charcoal canisters and they may lose effectiveness, but probably not after a day.

 

So what does the canister purge valve do? Is the valve open when energized or closed? If it's normally closed and it takes electricity to open it, then how could leaving it de-energized (closed) cause a fuel smell?

The JTIS really sucks when it comes to explaining the fuel system.

 

JTIS says, with no ECM signal applied to the valve solenoid, the valve remains closed. The way I read it, that means the engine is not fed fuel vapor, so the vapor continues to build in the canisters. The canisters are vented by a filter near the right rear wheel, and I think they will vent excessive pressure there. I think venting by the valve itself only happens if the valve is malfunctioning (leaking).

 

Well, the first time I started the engine I got no codes. The second time I got a P0445 (Evaporative fuel valve short circuit). I think the descriptor is erroneous because it's actually an open circuit, not a short circuit. I measured the resistance on the pins on the valve itself and it reads 32.2 ohms. I think I swing by Radio Shack tomorrow and pick up some 33 ohm 1/2 watt resistors and see if I can trick the ECU into thinking it's hooked up to the valve.

The car started "almost" instantly even though the engine had been turned off for about 90 minutes. Usually it would take 8-10 seconds of cranking to get it started after being shut off for that long.

 

this is what my car is doing also.

 

Instead of me typing away for hours, get a good idea of how OBD ll evap' systems function at www.autoshop101.com . This is a great site for learning about auto electrics, OBD ll, etc. I believe it was begun, and is maintained, by a Toyota instructor. It is supported (kind of) by Toyota and has several other contributors. While we aren't driving Toyotas I can vouch that many OBD ll systems have some common roots and the understanding of systems you'll learn here will, at the very least, help you with most any other make. For evap systems look in the 'Technical Articles' section and scroll down to 62 Emission#8 - Evaporative Emission Control.pdf (or click on the link I just provided... )

 

" . . . since the weather has dropped into the teens . . . ." In San Diego?

 

Anyone have an answer to H20boy's question about what happens if you do not get the ECM updated? The JTIS says it is needed for cars up to serial #A36752. The TSB says it is needed for cars up to serial #36998.

I am one of the lucky few that is beween those 2 numbers!!!!!

My guess is that the TSB is more up-to-date.

 

lol. the original poster has cold weather, my canister is probably just shot. i think it was a cool 64 here today.