Ferryman wrote:

To keep the cooler radiator in one piece you could try to heat the nuts for a short while, aluminium expands very quickly when heated with a torch (kitchen chef's torch).
If no avail your plan can always be plan B.

Given the OP's previous two fires, not sure I'd advise heating bits of car up with a chef's torch lol.

I read OP's problem about maybe not being able to complete drive cycles, didn't know if he had a way of resetting adaptive values, thought the above would be of interest anyway, hence the post..

I suppose from LR's point of view it's in their interests to identify every problem etc during one visit from a customer... and performing the drive cycles would help with that (as well as being a chargeable procedure in it's own right...). But for a fairly clued up DIYer or generic garage, it might be apparent that just one component is at fault, in which case my method of preventing further codes.... that would otherwise prevent drive cycle completion being possible... is a good way to go.

It doesn't matter to an owner if drive cycles are completed, it's of no consequence, no need to rush and perform special procedures just to get a thumbs up from an engine ECU, especially not if you're reasonably confident you've just fixed the one component you know was the underlying reason for poor performance / error codes, if you have a basic scan tool that can show you all is well as you drive even before drive cycles are completed (or don't mind looking into any further error codes that might become apparent at some later time)... my method works without Nano type equipment and without wasting any fuel, time or effort.

I believe the most fussy ECUs fitted on Landrover models with the the Rover V8 are in really late model Rover V8 Disco's, the one with EGR, which do turn on Mil lamps if there is a problem... still relatively unfussy though.

How low does the tank need to be before trims are locked OB? Quite a few LPG users run with very little petrol in the tank lol!

Simon

I've always considered P38 drive cycle tests to complete very quickly and trims to shift quickly. Also, they have a simple set of trims compared to many vehicles (which might have more sets of Ltfts and be quite fussy around idle).

I'm not familiar with the drive cycles you linked to but I am very familiar with the concept - Every vehicle ECU has a set of drive cycles that must be completed without any problems before the ECU will report 'IM readiness complete' (which is ECU's way of reporting all drive cycles/tests have been done and passed), each such drive cycle can be considered a test roughly aimed at checking a specific set of components under the driving conditions of that test, so for each component to be deemed as checked and found good it has to pass all tests aimed at it. But it isn't necessary to know the specifics of each test, because well before all tests are complete fuel trims (including Ltfts) will shift properly, the vehicle will drive properly, and as long as there are no other problems all the tests will eventually be successfully completed (and then IM readiness will show as completed) anyway. So, if you're starting from a point where you know only one component was at fault, and you know you've fixed it, then you know that pretty soon all tests will be passed. Tests can be guessed - they will include a warm up cycle, a cruise at low speed / higher speed, acceleration, an idle test, engine restart. Having cured the immediate problem and reset fault codes the vehicle should drive properly (may need to help steer the trims as in previous post) and no other faults should come up,. I've never needed to look up drive cycles etc either, just drive under various conditions, let the engine idle, turn it off, restart, etc. P38 tests complete relatively quickly just by normal driving but my scanner (which isn't a very expensive type at all) shows which engine components have passed IM readiness tests, so if for example scanner shows heater circuit on a particular lambda probe hasn't passed the test yet, I'll know that either the probe has an actual heater fault (but then it would usually come up with a code for open heater circuit anyway) or the ECU is waiting to see if it gets a viable lambda reading soon after engine startup (probe won't show correct reading when cold even if the sensor component in the probe is good). Of course, probe will only give a viable reading with cool engine running closed loop soon after start up if Stft isn't maxed out and if the probe heater is working properly... so it can be necessary to read between the lines (as is always the case with diagnostics) - IM readiness reporting probe heater circuit hasn't passed tests could be due to actual (maybe intermittent) lambda heater fault or could simply be due to Stfts being maxed out.

Work on a lot of different make/model cars and have never needed to look up vehicle specific drive cycles etc, not even on Valvetronic BMWs which have far more complicated ECUs, trims and drive cycles.. easier just to wing it / read between the lines. If you were to carry out all those drive cycles on a P38 it would take you over 30 mins, but I'd usually have IM readiness checks completed and passed in far less time. If you try to follow those drive cycle checks having replaced a component such as a lambda probe or MAF sensor you might be there a lot longer than half an hour, because you might never pass drive cycle A, which says start the engine up and let idle for 2 mins, because during that 2 mins of idle the ECU might come up with fuel trim error due to maxed Stfts as discussed above.

Simon

I've often read about marque specific tools being necessary to reset adaptive values etc but I've never needed to use any of them. After fitting new parts such as AFM's, lambdas, etc, for sure sometimes the mixture doesn't automatically correct if the vehicle is just left idling and that can lead to problems but there are ways of getting around the problems.

What can happen is that short term trims immediately reach an extreme (positive or negative) to compensate for improperly learned (when bad part was fitted) long term trims and when short term trims are at an extreme they no longer effect long term trims. So, e.g., if the vehicle is fitted with new probes and just left idling, a mixture error code can be generated. Imagine Ltfts have been incorrectly learned to -25% but the engine really needs Ltft's to be +10% for correct mixture. In this case Ltft's are 35% too lean, so if Stft's max out at +25% the engine will run always run lean because -25(long) +25(short) = 0, where we need 10, so the engine will run 10% lean and this won't auto correct because with Stft's at an extreme Ltft's won't adjust (we would need Stft's to max out at at least +35% for this problem to correct itself). If this situation continues we soon get an OBD error for mixture too lean, so then the ECU may go into limp mode and just ignore the probes anyway...I can see why resetting adaptive values is suggested here and on other forums/threads where this is discussed.

But, what I find is that if new parts are fitted and then the vehicle is held at fast idle, this is usually enough for short term trims not to reach an extreme regardless of long term trim state, and with short term trims not at an extreme they do effect long term trims, so long term trims are soon steered to around correct values... and then the vehicle won't generate any error codes and will run properly in closed loop mode. I just monitor lambda voltage and short term trims after fitting new parts, and then nurse the fuel trims back to normal (usually fast idle works, or may need holding on the brakes in drive while a bit of throttle is applied, or less often a short road trip where you can place as much load on the engine as you like). In case you're monitoring lambda/trims and haven't seen lambda flick or Stft's shift from extreme for a while, pretty soon an OBD code may be logged, but a quick blip of the throttle will usually prevent that, because this gives a blip of rich mixture (due to acceleration enrichment, so lambda lean timeout is prevented) and time out on any particular set of fuel trims is prevented (because after the blip the engine will momentarily go open loop). Seems to work on just about anything, P38s and all the fussy stuff like BMWs, Jags, etc that we're supposed to need to reset adaptive values on.

Simon

Dunno if you refer to my last post on this thread Dave, but I was talking about a different forum,

Surely these mods on the other site are short sighted. If I were a mod I'd allow any relevant external link and argumentative comment, they serve to build reputation of a forum as an open, none censored, unbiased hub of discussion. Starting down the censorship and anti free speech road, people will surely come to realise the forum can no longer be considered a central hub of info and will wonder what content has been intentionally hidden from them. That would be enough to prompt me to check other forums for answers anyway, counter productive. Incorrect arguments can be talked through and shown to be incorrect, it can all add to forum interest, highlights lack of censorship and builds confidence in the forum among users.

I'm effectively barred from Lexus Owners Club forum for mentioning Lexus models converted to LPG should have a valve lube system fitted and posting a pic of a Lexus I converted. Another LPG installer advertises on the site and doesn't advise lubes are necessary on Lexus models, one of the moderators whom had his Lexus converted there censors anything that might be deemed negative against that firm as hostile content, even if content is correct and could help some of his members prevent burned engine valves.

Simon

I reckon 11mm ends on that Matrix filter, could be wrong...

Reckon whether 19mm pipe will fit over 22mm pipe will depend on brand of pipe. I have various types of coolant pipe and find the better branded / thicker walled stuff tends to be less flexible than cheaper stuff. Would think if you've got to force pipe so hard to stretch, that can't be great in terms of potential future failure point either.

A lot of vehicles that use 19mm heater hose have a small section that flares out to maybe 22mm where it connects to engine / firewall fittings, could simply go to a scrappies and cut some from a relatively new engine bay to save that £40 (for a metre of hose, really?), this would be a solution to 22mm to 19mm pipe in 4 inches if that's a problem, though I suppose you'd have to weigh up pros and cons / longevity with the stuff I refer to being only thin walled. Does the 22mm pipe need some adaptor to 19mm anyway?

Simon

Hehe holes in the manifold will definitely cause vac leaks...

Since you ran out of gas during autocal it is possible that actual pressure could be very different to the figure you entered before, because even well before it refused to run on gas it could have been just about running on vapour - again check actual pressure and adjust reference pressure to match.

Orangebean wrote:

Petrol Lambdas look pretty good to me

So, set working pressure to actual, do the -20% thing and run autocal again ;-)

What injector type did you set, what type are fitted, and what are the numbers in the map after autocal?

On the 'efficiency' and 'inconsistent per cylinder fuelling' points, a good way to tell is by checking manifold pressure or AFM reading. More efficient should see lower manifold pressure and airflow for same rpm with proviso both fuels have correct mixture. In fact, that's a little unfair to LPG because really map and airflow should increase slightly on LPG, if they decrease it points to an issue with petrol injectors. But bare in mind LPG system's reported map can read slightly differently when it's reference voltages are slightly offset, so a slight difference may be due to the LPG ECU driving LPG injectors.

SImon

Would seem mixture went rich (or nearer to correct from previous drastically rich) when it switched to LPG.

Since it is more likely it went rich from correct or a bit lean, first thing first, is mixture correct on petrol?

Assuming it is, go into the map screen, select all the numbers in the table, press enter and apply minus20% to all those figures. Now, when you run autocal again, autocal will begin with a leaner mixture to start with so rpms won't rise as much when it switches to LPG.

Incidentally, if mixture is reading correct on both banks on petrol (lambda flick), sometimes you get a rise in rpm when switched to LPG due to a problem with petrol injector(s), i.e. some flowing more than others so per cylinder mixture isn't correct (only average is correct). If LPG injectors are all good, the increase in rpm can then be due to efficiency gains of the engine when mixture is correct on all cylinders. Particularly sometimes if engine has done a lot of miles on LPG and petrol injectors haven't been used much, or been clogged due to owner running on petrol with next to no fuel in the tank so injectors get fed with mucky tank dregs that made it past the fuel filter..

Simon

Also note that you might not see actual results of any changes to RPM detection settings you make until after ignition has been turned off. Sometimes it even takes shutting software down and re-starting software.

Where necessary (so not with more recent ECUs) I connect to one of the coils. One coil means one coil per cylinder, two coils means wasted spark, RPM means one pulse per engine spark (tacho usually), so RPM2 may work with wiring you have. If you get no reading or inconsistent reading with a particular setting here, try the 'weak; option.

Simon

Wonder what went wrong with your old ECU, since it was working before you started any work? Since a sure fire quick way to destroy an ECU is to apply 12V to chassis or earth connection while the other earth is actually connected to earth, might be worth one more check of wiring.

Best to click 'reset the ECU', enter all basic settings, run auto-calibrate.

At this point calibration it should be roughly OK on a P38, but you should note actual pressure when running on LPG, repeat the above but this time enter that actual pressure as the reference pressure when entering basic settings.

Only now start to adjust the map manually.

This is because (1) you won't know the pressure supplied by the reducer while running on LPG until you've actually checked it while running on gas and (2) the shape (as opposed to just the values over the whole) of the map will have been adjusted from standard to suit the last vehicle the ECU was on, while auto-calibrate simply lifts or lowers all the numbers in the map by X%. For most people it will be easier to start from a clean slate regards map shape and default map shape isn't usually far out on a P38.

Simon

That's 'em, but I wouldn't bother on a vehicle that doesn't pick fault with petrol injector resistance either!

I keep some 124's on the shelf, and because I fit a wide range of ECUs not just AEB I sometimes have to cut the plugs off 124's to hardwire... An upshot of this is that I end up with some loose plugs, which can be wired to bypass a 2568 (and certain BRC ECU's) entirely for diagnostics where suspicion is that LPG ECU or ECU loom/plug doesn't reconnect petrol injectors but are difficult to access.

No reason why it shouldn't work... if it's a good 'un and external wiring or component isn't the real issue!

Brown green brown, 150 Ohm? Although I believe each will be in series with a petrol injector while running on gas, resistor plus injector roughly 165 ohms. So say 14v battery voltage, series current of 85mA but voltage over the resistor would only be 12.7v.. At 12.7v and 85mA the resistor would dissipate 1.08watts. if resistor is rated at 1w resistor it's probably gonna get warm..

Obviously 165 Ohms is way different to petrol injector resistance (usually 13 to 16 Ohms)... Some petrol ECUs (not on P38s) notice this and interpret it as a disconnected petrol injector. so is necessary to address emulation resistance on some vehicles by fitting extra resistors in parallel with the LPG ECU emulation (about 40 Ohms usually does the trick). AEB124's are a neat way to do this, especially when using AEB2568 ECU's because they are a plug in solution (to injector break looms). Using AEB124's even where not necessary should take some heat off the ECU internal resistors.

Simon

Damage or just discolouration, though... Old boards that still work fine seem to get a bit discoloured in areas.

Reckon the big resistors are for petrol injector emulation?

Some of the other suffix boards are a different.design. Not related to your problems but since we're looking at a board might as well mention that if any of those little components at bottom left of top pic go wrong, you lose either peak or hold current to LPG injector(s). I dunno if some of those little 2 pin jobbies are diodes/resistors or what, but I do know that at least some ECUs use special diodes for timing peak.

Already mentioned I have an old broken OMVL ECU here (works OK on LPG but doesn't reconnect one of the petrol injectors when running on petrol).. I'm feeling semi inspired to have a look inside, see if there's anything obvious wrong. I will have a few other broken old ECUs laying around somewhere too..

Simon

I don't think there'll be a problem loading B calibration file into C ECU. Calibration should be almost right, but if 5V issue has been causing incorrect pressure and temp readings calibration may need minor adjustments after the upload.

Simon