1999 Rangie - V8 Problems - ECU

Back again guys - Hurray!! After three years away from Landie forums.

I have a quezzo from my Dad, he is pulling his hair out ATM over the engine peoblems he is having with his 99MY 4.0 Litre Bosch Motronic V8.

When the engine runs from cold there is no power and the unit will back fire, die, rev limit to 3,000rpm etc.... Once up to temperature it is spot on as normal.
He has changed the coolant temp sensor, the throttle pot, disconected the battery to hopefully reset the ECU. All with no result :-(

Fuel pressure is fine.
Diag tool on OBD2 annunciates the fault code for left and right bank lean mixture - no sh*t

Any ideas?
Alastair

Hi Alastair, I have recently purchased a Motronic 4.6 RR (2000 model)which is exhibiting symptoms similar to those experienced Feb 2006 by your Dad (no power when the engine runs from cold and the unit will back fire, .... but once up to temperature it seems seems 95% OK). This engine also has a 2001 Tartarini Etagas system, but that doesn't come in until the engine is warmed up.

I have today ordered up a replacement set a Magnecor HT leads on the basis that the existing 4 year old components are due a change out anyway, but I'm not really very optimistic that these are a root cause. What turned out to be the problem with your father's Rangie?

thanks for any help you or anyone can offer,
John Carter

Air flow meter.

listen to eightinavee he knows his stuff

Hi all.
He does indeed and i would be interested to know because, bless it my p38 with motronic management does the same i think. From cold it starts fine but instantly knocks v slightly, has no power, really struggles to move the car until its been running for about 1-4 mins and then is fine all day until the following morning. It has new a temp sender.

Speaking to eightinavee tomorrow but i think i'm just going to order the air flow meter, not too expensive at 70-80 pounds.

Cheers, Nick.

Hi Nick, communicating with ajmac (who originated this thread last Feb) he confirmed that the fault on his Dad’s 99MY was rectified by the fitting of a new AFM (so hats off to eightinavee who, as rangiep38 testified, certainly knows his stuff! And also many thanks to ajmac for getting in touch).

Meantime however, I received and fitted the already mentioned Magnecor HT leads at the week-end. I also checked the spark plug gap, resetting it to one mm (these are the standard double platinum plugs, which generally seemed to be sitting at around 1.2 mm). Whilst this maintenance does seem (judging by this mornings commute at any rate) to have brought about a significant improvement, power delivery is still pretty unsatisfactory (rather than abysmal) until the engine is up to temperature. Hence I have embarked on the next phase of expenditure, which involved purchasing an appropriate AFM from ‘The Portland Group’ who have an e-bay shop. For your info they accepted an offer of £60 all-in for provision of a new air flow mass sensor (LR# MHK 100800 / Bosch# 0280 218 010).

When this arrives I will fit it and revert with a further update……

JC

Hi.
Thats good news, didnt get to speak to jon (eightinavee) today because i had to go to sunny Bedford but if you think that its better i may order some when i order the Afm.

Did you know that if you disconnect the battery overnight the car will generate a new petrol map next time you start it, ( my car is a p38, 1999 with motronic ecu/Banana air intakes) but according to my local mechanic you need to drive over 19 miles on petrol, turn off the ignition before this and it doesnt save the data. I have done this quite a few times before after issues with my gas system and it works. You could do this after you have fitted the new afm and it should be much better. It goes from rich to lean three times so dont drive it any where until the tickover has settled, it sometimes seems like its going to stall during the process but it will sort itself out, assuming you o2 sensors are happy of course.

Cheers, Nick.

Better late than never!

My Dads P38 is in top form and has been all year after finding the problems, I'll note them here for all:

No power, lean mixture: Out of calibration AFM - new one, plus ECU 'reset' cured the problem.

Poor idle: Old HT leads, new ones transformed the Car! Wouldn't have given it credit....

Invoice to follow !

Could this be the cause of the problem that I have?

I've just bought a 4.6 HSE and I'm having a problem whereby when I start the car it won't idle - revs go to about 1750 and then drop and the car dies.
If I use the accelerator I can keep it running, but there's no power and I can't drive off.

After 30 seconds or so everything's normal and I can drive away.

It doesn't do this all the time, I haven't driven it enough yet to figure out if there's a pattern.