Disco II MAF Question

[jrichards64]

I have a 2000 Disco II with 117,000 miles on it. The Service Engine Soon light came on, and I troubleshooted it to the MAF, after pulling the following error codes:

• P1171 - System too lean Bank 1
• P1174 - System too lean Bank 2

I bought a new MAF and installed it, but after installing it, the engine ran roughly, and when I stepped on the accelerator, it hesitated. So I call the helpful guys at British Pacific and tell them there's something wrong with the MAF they sent me, and they sent me a new one. I installed the 2nd new one and I get the same problems! Is there anything downstream from the MAF that would cause the engine to run roughly and hesitate? Could it be the O2 sensors? Anything that I'm missing? Or am I just going to have to break down and take it to the LR dealership and let them run some diagnostics on it?

Any help is surely appreciated!!!

Jim

 

[joey]

First things first... is the air box clean and the lid installed correctly and tight. (I can't count how many I have seen with gaps around the lid or it installed slightly off).

Since it is a new MAF the odds are it isn't bad, have you cleaned the intake and the butterfly. Then last but not least you may need to either clear the ECU or drive it for a bit to have it learn the new part.

 

[jrichards64]

Maf

Joey, thanks again, you are the best! To give you a little history; in mid-December I performed a tune-up where I installed new spark plugs and a new air filter. At the time I performed the tune-up, the Service Engine Soon light was one, and you suggested I pull out the MAF and clean it, which I did. After performing the tune up, I started it and the SES light was gone! After about 3 weeks of driving it, the SES light came on again, and that's when I replaced the MAF the first time, to no avail... So, to answer your questions, yes the filter is clean, and the filter housing is on properly. I will clean the other components you suggested, and give it a couple of days to see if the SES light will stay on. I'll letyou know...

Thanks again!!!

Jim

 

[jrichards64]

Maf

Joey,
It's been a couple of weeks and the Service Engine Soon light is still lit, and the vehicle still runs pretty roughly. I get a slight hesitation at times when I start the vehicle, or when I accelerate from a stop. Any ideas? Or is it time to bite the bullet and let a professional look at it.

Thanks again!

Jim

 

[joey]

What plugs did you install, and did you or are you planning to change the wires?

 

[jrichards64]

Plugs and wires

Joey,
Thanks again for the response. I used the Bosch 4002 spark plugs, and I did NOT replace the wires. Would you recommend replacing the wires now? If so, I've seen you've recommended the Magnacore wires. Any particular model number for those, or just go with whatever the auto parts store has?

Thanks!

Jim

 

[joey]

Two things any Rover mechinic will tell you:

First get rid of the Bosch and buy Champion Platinums for the D2.

Wires (PITA) fun to change, but I would recommend Magnacores, not sure you can buy them locally or not. If not, buy the best wires they have, don't skimp on wires. Plugs, Rovers can be picky about.

 

[SCdisco]

Just unplug it

It will run fine. Also clean throttle switch. Figured out that faulty MAF sensor will kick car into limp home mode. I unplugged MAF and has recently been taken off limp home mode.

 

[jrichards64]

Well, I completed the job of changing the wires and putting everything back together, and I must say, it runs very well now, but what a freaking PITA! However, the Service Engine Soon light is still on. Do you think I need to have it cleared?

To review, I have installed a new MAF, Air Filter, Plugs (Autolites), wires (ordered from British-Pacific.com), but the SES light is still on. Overall, my Disco runs smoother, accelerates quicker, and just overall feels better. So, why is the SES light still on?

My next challenge is to get the 3 amigos to go away and replace the shuttle valve, which I plan on doing this weekend. Any tips or tricks? Do you recommend I remove the brake lines and take the modulator out, replace the shuttle valve, re-install the modulator then bleed the brakes to get any air out of the system? I know in another post, you said it's a major PITA too, so any help would be appreciated.

Jim

 

[joey]

Plugs I would have recommended Champions

CEL you will need to have cleared with an OBDII reader.

DO NOT REMOVE the modulator, you can't bleed the brakes very easily (It can be done, but not fun, and it will take forever)