May be interested to know that I sell DIY kits with tech support, calibration and 'sign off' included. Really not bothered if you buy from me or a supplier, more than busy enough as it is without getting involved with DIY kits etc tbh... But if you have qualms about tech support (TT wouldn't advise the plenum mod), calibration, sign off - and there may be good reason to have qualms in more than one of those areas - taking my route is a good bet.

I dreamed up the idea of the plenum mod to get around the manifold nozzle (spud) placement and pipe length compromises that most P38 installs have.

If you think my shoes lucky scruffy in that pic (inlet plenum on link above) you'd definitely think I lucky scruffy bent over engine bays with my outlet plenum on show... not that I'd want a bloke to look at my arse lol.

I doubt you'd break anything even leaving all the electrical stuff connected while you're MIG welding.

I'm not as familiar with P38 exhausts as half of forum members but have welded lambda boss's onto them. Only issue I can see is that the 'easy access' might not seem so easy access when it comes to welding... but I'd try it without removing the exhaust as you intend and would expect to do well.. just that the welding would've been easier if the exhaust was off. Of course there's then the balance between effort to remove / refit the exhaust vs the difficulty welding with the exhaust fitted.

Why do you now need the 3rd lambda?

Edit - 2 posts crossed with this. Of course I get the 0-1v sensor for the LPG system input, question is why now? A lot of the early mixer system ECUs could only work with a 0-1v probe but most later ones can work with 0-1 0-5 and 5-0v. If the lambda signal wire is cut (so the LPG ECU can supply the petrol ECU with an emulated lambda signal via 'grey wire') then even if the petrol ECU tries to pull lambda voltage the LPG ECU will still see correct lambda voltage.

For years I've been getting calls which seem to come in spats from various call centres asking to speak to Simon Miles (I'm Simon Andrew). Calls are often from Indian call centres but sometimes from UK centres. I used to ask them to remove me from their database(s) but it made no difference. During one call from an unusually apologetic UK call centre woman I was told they get numbers from an agency, she didn't know the name of the agency, couldn't delete numbers from the agency database, couldn't let me speak to her boss. About 5 years ago I pretended to be Simon Miles just to see what it was about and to mess them about in the hope they'd delete my number. I've forgotten what it they wanted Simon Miles for but it involved them taking card details to pay for something so after dragging discussion on for half an hour I eventually made fake card details up until it dawned on them. Then I gave them a bollocking and told them I'd mess them about every time they called so it would be in their own interests to remove me from their database. Five minutes later I got a call from another number, the call centre blokes supervisor telling me in Indian English 'You are not a gentleman sir'... 'You wont want to call me again then will you' but made no difference. I also often get 'Can I speak to the owner of the business' calls and half of them don't know what business they're calling. My number is all over the net so I suppose it's something I'll always get but I have no idea where they get 'Simon Miles' from.

I saw this thread just a few minutes ago and immediately phoned RutlandRover Dave to explain what's happening, what settings are causing it and why I made those settings.

The KME ECU allows setting momentary switching back to petrol if reducer temp or gas temp fall below a certain level if engine load rises above a certain level. The feature is useful as a safeguard (to prevent issues) and is also useful for effectively allowing setting of a cool changeover temperature at light to moderate engine load but a warmer changeover temperature for higher engine loads. The two points almost imply the same thing for the majority of vehicles but there are some vehicles (very high powered but with little coolant flow, which doesn't apply to P38s) where the two points can mean different things. *Edit: The two points can mean different things on any vehicle if some problem occurs with the vehicle in future, e.g. a partly blocked heater matrix could effect reducer temp stability at high engine loads if the reducer is plumbed in series with the matrix.

I set a cooler than usual changeover temperature but set the system to momentarily switch back to petrol if higher engine load is applied while either the reducer is below 20c or gas temp is below -5c. What's happening when Dave blips the throttle so soon after changeover is engine load momentarily rising above 30% (and 30% is more than you might assume, you could probably cruise at 100mph at 30% engine load) while reducer temp is below 20c, so causing the system to switch back to petrol... only during the throttle blip and only while the reducer is cold. But Dave notes it doesn't do this when he pulls away etc in actual driving even when the system has just switched over to LPG... that's either because engine load doesn't rise above 30% during those conditions or because when he pulls away the reducer has already risen above 20c. Note that this isn't the same as what is usually considered petrol addition or inability to run on LPG flat out, the system does run on LPG under any driving condition once the reducer and gas temp (gas temp won't be a factor here) are warm enough.

If I hadn't applied the settings it might have been a good idea to set a warmer changeover temp, in which case Dave would save less money because he would be running on petrol for longer during the warm up stage..

The OMVL injectors are perhaps the best performing injectors with cold gas (I told LPG shop this a long time ago and they seem to have invented a fake review on their website from someone who says OMVL are the only injectors that work properly in Alaskan conditions lol), the reducer is unlikely to get cold enough to freeze up or spit out liquid gas (causing high pressure problems) even if he booted it when the reducer was still at the cool changeover temp I set - So if Dave wants I'd be happy to leave changeover temp as it is and disable the facility and it would be fine,, but it is probably a good idea to leave settings as they are because (as Dave said) it isn't causing a drive-ability problem and the settings help make the system pretty much bombproof... I could trip most LPG installs that change over at normal/low temps up by immediately booting it following changover to gas from a cold engine start but even I would struggle to find a way to make this install throw a wobbly other than the compromise of the hesitation reviving the engine when it's just changed to LPG from a cold start. Many installers/customers have moaned on LPGforum about getting the balance between changeover temp (money saving) and owners likelihood of booting it with cold reducer right (thus causing drive-ability and component issues) right, the KME settings can be used to allow a very cool changeover temp while preventing problems caused by too cold gas / cold reducer in case the driver boots it very soon after changeover with cool temperature setting for changeover.

Just saved a screenshot of the settings I mentioned, will upload to the net and post a link when I get time if anyone wants?

Simon

I recently paid a local mechanic to change the water pump on my Merc ML, would have done it myself if I'd had the time but I'm too busy doing what I do best (LPG stuff) and thought I might need the ML to pull a big caravan I recently bought because I haven't had chance to fit a towbar on the Elgrand I bought yet. I'd have used my MOT garage for doing the water pump but he said he was too busy and didn't want to do the water pump anyway.. but it still went to him for it's MOT straight from after having the water pump done. I normally watch the test being done but this time I left it with him and picked it up the next day. When I went to collect he said it'd passed with some advisories... he'd noted worn brake pads all round. Funny that - because I put brand new front pads on the it last year and it's only done a couple of thousand miles since, they still look new to me. I reckon he didn't even look at the car because he knows I'll sort anything that needs doing anyway. Told him not to worry I'd sort the binding OSF caliper lol.

Hehe farts, are they that temperamental?
Hugh's was reporting both pre-cat probes broken heater circuits, no signal from one of them (other working OK despite broken heater), fuel trim lean error on the bank with the working probe. I advised both probes would need changing. Also the bank with working probe consistently reads +20% ltft over all rpms/loads so the MAF might be reading too little airflow too, won't be a vac leak if it reads the same +20% at higher loads and rpms. His metal plenum gasket had RTV both sides which I cleaned off before re-assembling.

Mentioned the other day that the EML is disabled on UK spec pre-2000 P38s. Think I'm right in saying that it'll not come on due to OBD errors but should come on when ignition is turned on, then go out and not come back on again when the engine is running even if there are OBD errors?

It was me that advised Hugh he needed new lambdas, I recently converted his P38 to LPG. OBD reports both pre cat probe heater circuits are broken, one lambda still gives signal the other doesn't. Also the MAF seems to read consistently low (all loads and rpms), either that / or petrol pressure is down / or all 8 petrol injectors are flowing less than they should... so it seems MAF is the most likely of those situations. LTFT's consistently (again all loads and rpms) at around +20% on the bank that is running closed loop and it's new enough to be almost fully OBD2 compatible as opposed to showing 99% LTFT's like the older models do.

Hugh has said he isn't getting the mpg he expected on LPG, I calibrated the LPG so trims (on the good bank) are the same as trims on petrol so hopefully things will improve when the lambda's and possible MAF are sorted.

Since Hugh's I converted RutlandRover's P38 to LPG as well. Also 'effected repair' of a water leak from the throttle body on RutlandRover's... Bypassed the throttle body heater for now because it seemed the TB heater itself was leaking but left enough slack in the replacement water hose so that he can re-connect the TB heater when he's fixed the leak on it. The plastic water pipes to the TB heater snapped in many places when I only went to disconnect them from the TB lol... But it was leaking from the TB well before then and RutlandRover supplied water hose for me to prevent the red stain from below the TB from recurring. I reckon I see more problems with fragile plastic water hose on P38s with red acidic coolant than I do on P38s with blue glycol coolant...

Agreed with Gilbert.

Only times I've seen plugs in that condition is when I've removed them and left them outside for a day or so to rust.. in which case of course they wouldn't have looked like that when removed / Or from an engine that hasn't been run much in a while, particularly if coolant has made it's way into the cylinder or if the engine had none-hydraulic valves and had been stood with exhaust valve open on that cylinder.

If it is a fake NGK it still begs the question how it rusted on the threads... I don't know it spark plug thread repairs are ever done with e.g. helicoils on these engines but such repair could maybe account for rust on threads and different compression?

The front of the single pipe is a terminating block under the transmission tunnel, the single pipe splits into 2 pipes within this block, the 2 pipes then run forward to the usual 2 pipe AC stuff under the bonnet. I haven't had a look at the rear evaporator yet, it may be that there's some sort of single pipe to 2 pipe adaptor before the evaporator unit or it may be that the evaporator unit is connected directly to the single pipe.

Might be possible to remove the single pipe and just weld the affected area... but the last time I tried aluminium welding myself was using a mig on a Vauxhall Senator's heater pipe and it didn't go so well! If I were to do it again I'd practice first on a bit of AC pipe removed from a scrap vehicle. Wonder if they are aluminium or an aluminium alloy though.

Not trying to change the subject but if I'm allowed to digress from P38s a bit... I recently bought a Nissan Elgrand people carrier which has 2 AC evaporators (one in the front and one in the back). AC wasn't working, didn't have time to take it for a proper regas so I tried the Halfords kit. It worked at first but then the missus could hear a hissing from the back end and it stopped working - hissing coming form the corroded front to rear AC pipe on a bend near the rear. Normally I'd probably try cutting the corroded bit out and replacing with some compatible high pressure flexible pipe (like I once did on a Pug306) but this pipe has another pipe running inside it. A new pipe is over £1000 and special order from Japan so bugger that! I need to either find a replacement pipe in a scrappers or fix this pipe.. Anyone good at aluminium pipe welding?

Here's what UKLPG's Mike Chapman had to say about it.

To all UKLPG approved autogas installers

LPG suppliers are currently experiencing a delivery backlog to bulk LPG customers which is due to supply issues from terminals first felt earlier this year which were then exacerbated by the extreme weather conditions experienced across the country. This combination is unprecedented.

UKLPG supply member companies are operating extended delivery times to deliver LPG to customers and increasing staff levels to improve the situation as quickly as possible.

Regards Mike Chapman.

Charlie Browns was running an AC regas, AC works or no fee operation until recently and I think other firms do the same; bur I've been past what was a Charlie Browns today and noticed it had changed to a 'Tyre warehouse' which doesn't run the same AC scheme.

Can buy a DIY AC recharge kit from Halfords, I have one but it's only really economical if the AC just needs a top-up, otherwise you'e better off going to a 'no win no fee' setup as mentioned above.

A very basic test of AC system condition (as in leak / no leaks) is just to depress the low pressure side schrader valve, it there's still pressure in there chances are it just needs a regas.

When it switches from stone cold the reducer temp sensor wiring is probably shorted, when it won't switch it's probably open circuit, OMVL Dream reducer temp sensors fail more often than most. From memory the thread is bigger than M6, probably closer to M10, the temp sensors get corroded in and then trying to remove them with a spanner rounds the brass hex of the temp sensor... Better to remove them using a 12mm hex socket after cutting the wires as close to the sensor as possible.

Sometimes when the proper Dream temp sensor fails installers remove an allen/torx bolt that holds the reducer together to fit a more generic sensor but not all sensors have the same electrical spec.

Said before that Tartarini systems were available with Matrix XJ injectors. OMVL systems were available with Matrix HD injectors.

The HD injectors are good performers but not as good as XJ. HD injectors aren't as reliable as XJ (actual injectors), actual injectors aside they also suffered a lot of internal temp sensor problems.

May find that the gas inlet on the HD's is 11mm and most 12mm pipe will still seal if an appropriate jubilee clip is used. OMVL kits used to come supplied with pipe clips instead of jubilee clips, a pipe clip with a purple band usually fitted OMVL brand pipe on 12mm fittings but were too slack on Matrix injectors so we used jubilee clips with Matrix injectors. OMVL brand pipe is thicker walled than most 12mm vapour pipe so the clips could only be used with OMVL pipe even on 12mm fittings.

If your injectors do have 11mm inlets and you have any problems you could change the inlets to 12mm or fit 11mm pipe, most of which can be persuaded to fit on 12mm fittings on filters etc.... especially if you heat the end of the pipe in a pan of hot water.

Good stuff. Yeh I'm warm in my long sleeve Tshirt, jumper, another jumper, coat and hat :-)

Gilbertd wrote:

Morat wrote:

See you on Friday, Simon! (I'll get that photo of the LPG injector plug when it stops pissing down)

Have you broken it already?

Morat wrote:

it's the Jeep, it needs some TLC.
Sadly it's just started throwing a check engine light with codes for the MAP sensor. I've changed the sensor and then it did it again :/

I know the Jeep ran better on the way home, is it still OK Morat (besides the PAS pump)?

Always a good idea to impress upon any MOT garage that you will be doing all your own repairs, so from their point of view a fail will mean them retesting the vehicle for free within the next couple of weeks ;-)