92 LPG RRC V8 AUTO Idle issues and Smock

Hi guys.

SORRY ABOUT THE LONG POST..... I can't find another thread to answer my issues... and yes I've done a search and read for hours.... but all other seams just a little off topic for what I think I'm experiencing. Here goes;

1) RR went in for an MOT Spe 09 with slightly high Idle but running well with no smoke.

2) Failed emissions quite spectacularly so was re-tuned ( I think) to get her through and Pass.

3) About Mid Nov 09 developed a mild ghostly miss on hard acceleration in mid range revs... and had a low idle when engaged Drive... so not wanting things to develop - took it into get sorted.

4) Plugs and new HT leads. Lasted about a day then had to go back to the garage with V.low idle (about 250.. first line) with idle revs dropping to near stall when moving off with light throttle.

5) Came back after a re-tune as they thought that they had got it a bit weak when it was done for the MOT.

6) Went straight back after 30min off me as she was no different. Stalled on the way there. She was in over xmas standing whilst we waited for a new vacuum advance to come and be fitted.

7) I've now been driving about a week. Then the old symptom comes back;

7A) On initial start up. White smoke out the back end and idle is fine. After about 1 or two minutes... as she starts to warm Revs slowly drop back down to about 750 to 800 in park or neutral.

7B) If you engage Drive or Rev with foot on the brake. Idle rev drops to about 250ish again nearly stalling before you do anything.

7C) When you do touch the throttle, she nearly stalls bogging down quite badly. about 50% of the time cuts out.

7D) If you dump the right foot in Neutral, she again splutters, boggs but clears and revs like a maden. In drive and on the road from traffic lights for example, she boggs and really struggles to recover but does... just.

8) What I have done (after reading this forum);

8A) Taken out and cleaned the stepper motor (air bypass).

8B) Had a ganda at the MAF.. but mine is a LUCAS 3A sleed unit and can't get inside (no screws on the top) so can't really do anything to it.

8C) Checked the TPS with meter. Mine is a fixed position type (think for the US market) unlike the UK type which seams to be able to be adjusted to rise or lower the reading. Anyway; mine came in at 498 instead of the Haynes 323. Could this be whats wrong? why is mine not adjustable? and can I fit one that is? (but part number?)

8D) So... I'm stuck regarding the Idle

AND

9) A little bit ****ting myself about the smoke to be honest that the head gasket has gone or stems (not that I know what they are but there are inside the engine right?) have gone?

10) I'm not using ANY coolant, and the oil (although could do with a change) is showing no milky or gunck.

I really want the RR to be running fine, but am having to consider how much I'm going to spend on her. I don't think I'd go down a head gasket bill as I suspect it's about £400 and if the lining has gone.. that's more right? or can you do both at the same time?

I have a list of things to check like Fuel temp Thermister, Coolant Temp Thermister and the ECU Main and Fule relay (but don't know how to check them at all.

I also read about check the ignitian timing. Could this have been knocked out when the Vacumm unit was fitted I wonder?

I also noticed that the IDLE screw looks like a philips head that's rounded and am wndering if the idle has been changed and can't be pulled back up.. but would a wrong idle setting produce these symptoms... would a mix cockup setting produce smoke.

The smoke is more White than Grey.. but I have noticed that since the MOT... the stainless tail pipe end has a heavy black soot on it. But the fumes don't smell of anything if I'm honest.

Oh... she does the same on both fuels... if that helps.

Any advice? I'm in East London.

Ok m8, you are in a similar position to me over Christmas after I fiddled with that idle screw (which is allen headed by the way) and then had a series of incompetant mechanics trying to sort it out.

Your best bet is to give stuart (vougese39) a private message on here, tell him I sent you and he will come down to you and sort it, it will cost you but its cheaper in the long run!

Btw we never got my idle up by very much but it doesnt stall!

Welcome to the club! Your probs sound very similar to mine which after causing me no end of grief seem to have magically vanished the last couple of times i've used it

Right... I've now taken out the flame trap and the breather pip that tuns into the T-piece. The flame trap smells to high heaven of fuel / gunk and is pitch black... no idea if the thing is blocked as its just a big bundle of wire wool type thing.

The breather pipe has however (on the trap side) got some gunk (like you'd find on the inside of the oil cap if the head had gone... what does this mean? early signs of head problems or just normal?

Well my pipe was split and all full of black crap so I threw the pipe away and fitted a new one, now when I check it it just has new clean oil in it (as the engine oil is nice and clean finally after three changes and taking the sump off and cleaning it out).

The flame trap is a bit harder to sort as when I tried ordering a new one it came back as out of stock from a few places, so I soaked it in petrol for a a while twice and rinsed it out with petrol too, (dried it before putting it back). I read afterwoods that you can push our the wire gauze with some dowel, unroll it, clean it , re-roll it and put it back so thats on my jobs list for the future.

I also took off the rocker cover that side and cleaned it out and the channel inside that leads to the flame trap comes off with two screws and there was alot of black crap in there too.

I have to say all my crap was black stuff, no emulsified oil.

Not sure any of this would cause your problems though???

Few questions for you:

Did the emissions fail on both gas and petrol?

What was the problem, Hydrocarbons or CO?

Do you have a sequential gas system or single point? (one hose going to a ring on the intake manifold).

First thoughts, if your gas system is single point and the problems are common to both fuels, I would be looking at the ignition side of things.

Cheers

chris

For what it is worth I would be inclined to check/clean the stepper motor, take off and clean the plenum and ram housing, check/set throttle disc.

Your ignition timing may need to be checked, I think it has a different setting to standard to account for LPG (you'll need to check what it needs to be). It might be wise to also check/test your lambda sensors - failing sensors may cause some of the problems you describe.

Lastly, try a substitute ecu.

Good luck.

RAGTAG:

Failed on both Fuel... but the current issues happen on both fuels and don't seam to show any differences between the fuels either.

Single point. I'm wondering if the fuel temp sensor has gone... but how the hell do you test it. The replacement is too expensive to just swop out and hope at £70ish.

jwaldron said:

Single point. I'm wondering if the fuel temp sensor has gone... but how the hell do you test it. The replacement is too expensive to just swop out and hope at £70ish.

Click to expand...

If you have a Haynes manual it tells you inthere how to measure the resistance of the thermistor, it can be done either by measuring across the ecu plug (can't remmeber which pins off hand) or you could measure resistance at the thermistor itself. You will need to know what the temperature is and then check the measured resistance against the stated values.

BTW have you checked your air flow meter?

Ok, it’s obviously difficult to diagnose from afar but a couple of observations from what you have said.

White smoke: It’s been pretty cold lately and you are not loosing coolant. Is it possible that the white smoke is just condensation?

Blocked breathers: This is not a good sign but you can eliminate this from the equation by temporarily venting the rockers to atmosphere and blocking up the other end. (I do this anyway by venting to a catch tank. Why hose oily mist into your induction system?).

The gas and the petrol systems are completely separate yet you have the same symptoms with both. This suggests to me that the fault lies with something that is common to both such as: air intake, ignition (timing / spark / coil etc), manifold leak

The only other thing that I can think of would be that there is a fault in the gas/petrol switching and you are actually getting both fuels to some extent. I have known this to happen but I’m not sure what the effect is. Certainly you would be running rich which is like running with the choke out.

Not sure if this is any help

Cheers

Chris

One other thought; if you have got cats, a lazy or failed lambda sensor could cause it to run rich, misfire and all sorts. Might be worth getting that checked out.

Right then...

I'll be ordering a new flame trap and breather pipe and coil I think as these are quite cheap from what I can find.

I might even do the Rotor arm and the dizzy cap for good measure.

I will then see what the score is and then if needed start on the lamba, coolant and fuel sensor.

The I'm stuck other than timing and air gap.... trying to stay away from the dizzy if honest as I don't know what I'm doing with it.

Will update once I know more.

Let me know if you find a flame trap!

fett said:

Let me know if you find a flame trap!

Click to expand...

You could try here

606168 In Line Breather Filter - 3.5 V8 Carb

Not listed for EFI but they're all the same, I think.

Cheers

Chris

Found one...£12.50

Famous Four - Search Results - Classic Range Rover 1986-95 Models

Yeah , I found them listed but when the order came they were "parts unavailable"

Let me know if they come through!

Ragtag said:

You could try here

Not listed for EFI but they're all the same, I think.

Click to expand...

My mistake, of course they're not the same:doh:

What about here? They say in stock

Land Rover Discovery 1 Engine Breather System - All Models at www.rimmerbros.co.uk

Chris

I wonder if that chrome one would fit, guess you have to blank off the pipe?

After inspection of the Flame trap and a second look at the breather pipes... they are not blocked... they will take wd40 which runs through without issue.

I'm looking to replace the collant and fuel temp sensors, dizzy cap, rotor arm and leads along with coil. I'm currently looking at Brit parts (which I've heard are ****).

My mentality here is to replace a lot of part cheaply.. then if they fix things; then start replacing these out with genuine parts before the (so I've seen 'brit **** parts) fail on me.

Am I thinking wrong here... will br the brit part licking just not work or do they just fail quickly... Is my mentality ok. I can't affort all these as genuine parts as the dizzy cap is £30, arm is £20, Leads £15, Coil £30, Fuel temp £80 and Coolant £20. By my maths that's £195 in parts. Brit parts lets me have all of them for about £15, £5, £20, £30 and £5 totaling only £65. BIG difference if only used to find out whats wrong.

Any ideas on this.

I had no end of problems with lucas parts but not genuine landrover parts made by lucas. there is a differnce apart from the price.

I couldnt even get mine to run on all cylinders without warming up in the morning first on the lucas ones but after I fitted the landrover ones I could drive it like a normal car right from the word go lol.

Also the arcing in the dark from the leads was there with three makes of leads including brandnew bosche and lucas but with the landrover ones there isnt any.

I will never buy non genuine ignition parts again, untill I fit a complete mallory system that is lol