Howdy Jag lovers!
Baby (97 XJ6 USA) just threw her first codes ( P1177 ). I just had a local parts store look them up for me, and I forgot to ask them to clear the codes.

It sounds like this may be a potentially ignorable code, as I am not having any functional issues. Does anybody have experience with P1177 (no others were thrown)?

Also, is there a simple way to reset the codes without doing the old disconnect battery trick? Perhaps a fuse, or a button, or a wire that could be grounded (or wire a reset button to)?

 

DTC guide for you.

bob

 

page 14/20 , Long Term Fuel Trim Too Rich - Banks 1 and 2 (FMFR) other sources words

Jaguar's words

 

Hmmm. So I guess I need to check (blow out) the fuel return pipe, then look into the fuel pressure regulator. I doubt it is the MAFS.

I attempted to clear the codes but disconnecting the battery, and held the leads together for 30 seconds. Doesn't appear to have done anything, even my radio presets are still there.

 

You need a code reader/resetting tool to turn the light off.

 

Probably the easiest thing to do is to revisit the shop or auto parts store to have them reset the light . Drive for a week and see if P1177 returns . Can't troubleshoot until you reset the fault flag . The LTFT is a learned setting that takes some miles and throttle up procedure to relearn the setting . It my be just a hiccup . By doing the Jaguar " Hard Reset " the ECU has to relearn the LTFT as well and the code is inhibited until the procedure is naturally satisfied in normal driving . This is a factor to consider in troubleshooting . External factors outside of the ESU that it can't adjust to is the other half . Since Fuel Pressure Regulators don't last forever and are cheap and easy to replace ( $ 65 ) and easily available locally it would not be a waste of resources . Fuel pressure after the FPR is 43 PSI at idle and bumps up to 46 - 47 on throttle up by the vacuum hose on the back of the FPR you can't see . Clogged return lines would keep it high . Some things are " Hard Reset " as you hold the cables overnight but then you know the danger of loosing the radio code .

 

Update: I got a code reader for myself and cleared the P1177 codes to turn off the dash light. "Baby" has thrown no fits for the last 1200 miles, so it was just a hiccup so far. I will do some Sea Foam next week for preventive maintenance. I am planning to use the brake vacuum line to suck up half of the sea foam directly to clean out the intake, then dump the rest in a half tank.

 

I know people do the"suck it into your engine"thing but I could never get my head around that. Why not pull MAF and TB and clean each with appropriate aerosol cleaners? Get a FP gauge and measure rail pressure directly. Also think about fuel injector cleaning?

 

I don't get the Seafoam thing at all.

It's not the 1950s anymore.

 

Easier said than done, Ric. There is no Schroeder valve nor port for one on these. I've obtained a couple of spare engine bay fuel lines for future fitment of one; there is a thread or two in here with pics where innovative people have fit one. (this statement should, in no way, be construed as any sort of defense of SeaFoam) I'm just saying, "it's not as easy as buying a gauge and tapping an existing port."

 

Mikey,

Like you, I'm naturally suspicious of all third-party fuel system cleaners, especially those added to the fuel tank, which are typically based on common solvents like mineral spirits and naptha and when used as directed are diluted to such a low concentration that any cleaning ability must be minimal.

But some of the products that are injected into the air intake after the MAFS seem to have some demonstrable effect. Here's a video of what appears to be an unbiased test of the Seafoam intake cleaner that seems to demonstrate the removal of at least some carbon from the tops of pistons. I've used this product in a few cars and the treatment seemed to help, most notably in a Mini with direct injection and heavily-carboned valves:


Also, some automakers recommend the use of certain fuel injector cleaners that are forced directly into the fuel rail. General Motors instructs its dealership service departments to use the product shown below when a vehicle exhibits certain symptoms. A special canister is required, in which the cleaner is mixed with a small amount of gasoline and forced into the fuel rail under pressure.





Cheers,

Don

 

TSB 303-67

Jaguar Cars recognizes that there are many types of commercially available
pressurized injector cleaning kits as well as cleaners to choose from. You may use any
existing equipment you have provided you are able to obtain satisfactory results.
However, if you need to purchase this equipment, Jaguar Cars recommends the Ford
Motorcraft Pressurized Injector Cleaning Kit and Motorcraft pressurized injector cleaner.
This equipment has been fully tested by Jaguar engineering and has been found to
perform to Jaguar Specifications.
The Motorcraft Injector Cleaning kit, CM-1000 and cleaner, CM-1001 can be obtained
through Excelda Manufacturing, (248) 486-3800 ext. 114 Kristi Mitchell.
Note: Please have a Credit Card available when ordering
Additionally the Wynn’s brand Injector cleaning kit and cleaner are also recommended,
and can be obtained from a local distributor. To locate a distributor call (800) 989-8363
or visit Wynn's USA | Wynn's Preventative Maintenance Products & Services.

 

Thanks, I've seen that video before. The problem is that the mount of carbon in the before pictures is pretty insignificant and well below the threshold of affecting performance, fuel consumption or engine durability.

The tiny amount of contamination that was removed will soon return, so the time and money spent on the treatment was wasted.



This is true. In addition to what Bob has posted above, JLR has issued bulletin LTB00409NAS2d applicable to Certain Land Rover products should they exhibit a loss of performance or poor idle.

The OP's car, like 99% of the cases that appear here, do not match the basic symptoms.

My view of Seafoam (50% petroleum oil, 25% naphtha and 25% rubbing alcohol) remain unchanged.