It started happening last Monday. Doesn't seem to be consistent. I've had it where starts normally, but will sometimes stall right after starting. One time, it didn't want to start. 2nd try, it started but was running rough. Tried it again, started normally and ran normally.

There is no CEL light present. But it does have two stored codes. P0172 and a P0175. Which is both banks rich.

I primed the fuel system 4 times, by running the key to the ON position. Immediately pulled the vacuum line right off the fuel pressure regulator. No raw fuel cam out of the line or regulator. Connected the vacuum line back on to the fuel pressure regulator. Started the car. Let it run a few seconds. Pulled the line, no raw fuel. I can't give it a fuel pressure test, because my fuel pressure gauge is bad. I have ordered a new one.

Air filter looks brand new. Took the MAF out. Is that too dirty?

 

That little bulb on the right side is actually the air temperature sensor and it doesn’t look that dirty. If you use a flashlight, look up inside that little tube just to the left of the ATS. There’s these 2 very small rectangular things being held in the middle by a wire on each side. I’ve used brake cleaner and compressed air hundreds of times without issue. I’d start with cleaning that first. Then I’d clean the throttle body by spraying a cleaner (preferably carburetor cleaner) on a rag and with the key off, open the butterfly with your fingers and clean all the carbon off the blade and bore of the tb. After that, I’d do a hard reset and then just drive it like you normally would. If it still acts up, then check the fuel pressure once you get your new gauge. If the pressure is good and it still acts up, I’d be suspect of the MAF or the tps.

 

I'll do that, and report back. Thanks!

 

Fuelfilter was my issue w/ similar symptoms.

 

I think I will change that, just as a maintenance piece.
Drove the car yesterday, let it sit for about 2 hours. Pulled off the vacuum line from the fuel pressure regulator. Inside of the line was dry. But when I touched the nipple on the FPR, my finger was moist of fuel. I couldn't word it any better or worse that, lol! No fuel dripping, but it just my finger have some moisture of fuel.

 

Two great checks. Although it sounds like a bad fuel pump, you might want to check the cam sensors. On my wife's POS Maxima, oil drips down from the valve (cams, really) covers which have old gaskets and shorts the sensors. Haven't seen many issues on 308s but as time and miles build on these some more common to all cars-type issues are going to surface.

 

Hi Brandon,

The intake air temperature sensor (IATS) bulb on your MAFS does look dirty in your photo. CRC makes a special MAFS cleaner spray formulated to dissolve the deposits that collect on the IATS bulb and MAFS hot wire/film. Most auto parts stores carry it. In my experience it is more effective than brake cleaner or electronic cleaner, though at least both of those are also zero-residue products. I've also found that the CRC Throttle Body Cleaner is better at dissolving the black gunk that collects in TBs compared to their Carburetor Cleaner, which is designed to dissolve the varnish that forms in carburetors.

I'm trying to reconcile your rich running codes with a fuel delivery problem. You would think that if one of your fuel pumps was under-performing, or if a fuel pump relay or fuel injection relay was failing intermittently, you would have lean codes.

Your dirty MAFS could cause rich running. Other common causes of rich running include an obstructed air filter; leaking fuel injectors; the fuel pressure regulator (FPR) holding excessive pressure in the rail or allowing raw unmetered fuel to be inhaled into the intake manifold via the vacuum fitting due to a ruptured diaphragm; the engine coolant temperature sensor (ECTS) stuck at a cold reading, causing the engine control module (ECM) to continue to apply cold-start fuel enrichment even after the engine is warm, or a stuck-open coolant thermostat leading to the same ECM behavior; worn spark plugs that aren't burning all of the fuel; etc. Often, a combination of these kinds of issues are contributing to the problem.

You may have found the problems at your dirty MAFS and leaking FPR.

If your scan tool can read the engine coolant temperature signal, that would be my first check. See if the engine is running cool due to a stuck open thermostat or the ECM thinks so due to a faulty ECTS. An implausible reading such as -40F is a clear indication of a problem with the ECTS or its electrical connector or harness. A plausible but low reading such as 170F or 180F may mean your thermostat is stuck open.

Also, if your scan tool can read the fuel trims, look at your STFT and LTFT. High negative long-term fuel trims indicate the ECM is shortening fuel injector pulse-width to reduce fueling in response to an indicated rich-running condition.

Cheers,

Don

 

Cleaned the MAF sensor and TB with the correct cleaners from CRC. Will do a hard reset, and drive it. See what it does.


and I cleaned under the plate as well.

 

No start today. Luckily, it decided to not start in the driveway of my house. No fuel pressure gauge on me. But I got a pick, put the key in ON position. Pushed on the Schrader valve. Very weak shot of fuel. Hardly any came out. Swapped the relays in the trunk, same story. So looks like I'll be needing fuel pumps. Sucks becasue I just filled the tank the other day lol. Any suggested pumps/fuel pump kits to buy?

 

If I recall correctly, the original pumps were made by Denso, so that might be your first choice if you can find one. Other Jaguar fuel pump OEMs include Pierburg and Walbro. The last time I checked, the online discount Jaguar dealers wanted around $400 for a "genuine" Jaguar pump.

Search the forums - I seem to recall some members having luck with pumps purchased on eBay.

Cheers,

Don

 

Delphi DEL38-K4014 is plug & play @ a great rate.

 

Car started just fine right now. I was hoping it would, so I could move it in front of the garage. I don't want to change the pumps for no reason. Yesterday, when it wasnt making pressure, it was very hot. 90°F. It is currently 70°F. Maybe the heat has something to do with it? Thanks for the pump suggestions. If I do end up having to change the pumps, what all should I replace "while in there"? Fuel pump wiring etc?

 

I did several searches, and all of it is old info. Or, the pump kits people were talking about, I cannot find anywhere. Hence my reason for asking. Saw people said to change the "in tank leads" I guess "leads" is some sort of wiring in the fuel tank? Anyone have a link on where to buy it?
Also, all the kits I'm seeing on rockauto and partsgeek don't say, or show if the fuel pump filter comes with the kit. Since this is an R, do I need to buy 2 fuel pump filters?
Or a parts list of all the parts I need would be nice. And yes, I have done searches. Most of the discussions lead to people arguing on the correct way to do the job.

 

When I checked to see if it had fuel pressure, that blue cap fell down somewhere in the engine. I have looked and looked for it. Nowhere to be found. Should I worry about that causing a fire? The old fuel pumps are dated November 2001. So they are originals.


To anyone in the future that isn't sure on what to buy:
R's use two fuel pumps, incase you don't know.
2 fuel pumps. I bought the Delphi kit from rockauto.
1 fuel tank seal and 2 fuel strainers(fuel pump filters)
I bought those OEM from partsgeek.
Also buy a new fuel filter. I bought a mahle fuel filter. Haven't installed it yet. I will.
Also, major thanks to my dad for helping me with this.

 

Same two codes are back. I've put about 400 miles on the car since then. So I doubt the throttle body is already dirty. Will start looking at it later today.


EDIT: Codes are back, but no stalling.

 

If your scan tool can monitor Live Data, watch your coolant temperature with the engine cold and at full operating temperature. If the coolant never exceeds 200F/93C, your thermostat may be stuck open or your engine coolant temperature sensor (ECTS) may be failing.

Also monitor your MAFS signal. Typically, at idle the MAFS signal will read approximately 0.01 pounds per second, 36 pounds per hour, or 4.5 grams per second, depending on the units your scan tool reports. The MAFS measurement should rise consistently with engine speed.

Cheers,

Don

 

I did see 203°F on my scan tool, yesterday. So I believe the ECT is fine. But will verify at cold start. Yes, I can read what the MAF is seeing.

 

ECT and IAT seem to be reading fine. Coolant got up 203, and fans shut off at 195. At idle. The check engine light was lit on the dash. But when I scanned it, they were stored codes. Not pending codes.

Fuel pressure at key on engine off, is 42psi
Running, 39psi.
WOT, 48-50psi.
Shut the car off. Fuel pressure went from 42psi to 20psi in 2 hours. I don't know if these fuel pressures are correct for a 2002 xjr.
Here are some screenshots of data.

 

The fuel pressures are fine. One thing you can try is inspect/clean the pins in the MAF socket (don't use any dielectric grease in it). Plug in the connector, start the engine and wiggle the wire loom to the connector and the connector a bit to see if it causes any change in engine rpm/sound.

 

Would electrical contact cleaner work?