328i on AEB2568 / Ultragas /Mint lpg

[rossjp]

Hi,

I got my 97 328i coverted by Mint LPG (Near Newport). It's an AEB2568 ECU with Ultragas Powermax vapouriser and injectors. When I got it back it had idle problems (misfiring of idle and stalling when you dip the clutch coming up to junctions, no problems on petrol), so I read the car ECU codes, which said the bank 1 O2 sensor was faulty. I replaced it and fitted NGK LPG spark plugs - the MPG seemed to improve but the idling issues remained. I took it back for a re-tune, which improved things slightly but still sometimes stalled when dropping to idle. In the mean time I read that if you change one O2 sensor you should change them both, so I changed the other too. No change in the running, but noticed intermittant occasional flat spots while accellerating hard. I have since checked for vac leaks around the manifold with carb cleaner, replaced the PCV and pipework, cleaned out the idle control valve and checked the car ECU for faults - the only ones which came up are bank 1 & bank 2 O2 sensor outside range (which means too rich or too lean). The plugs appeared quite black with bright white on the electrode (which I guess means it's sometimes rich and sometimes lean).

I took the car back for another tune, they said it was done but when I picked it up the idle was worse than before. It misfired more on idle and stalled at most junctions. However, it does now pull better (no flat spots). Not sure on the fuel economy yet as haven't got through a tank. I will know on Thursday. The car fuel computer says the MPG is better, but it depends what has been changed in the set-up...

I have now bought a serial lead and got the program, so can tune it myself. I have copied some of the things this guy has done, becasue it sound like a similar problem:

http://www.lpgforum.co.uk/viewtopic.php ... 16&p=86679

I don't know if the micro-injection thing is a problem with BMWs as well...

The Magicjet configuration won't work on mine because it doesn't recognise the file type as being a config file. I tried the King software, because it looks the same as the AEB software I have but it won't recognise my ECU.

What I have changed is the 2.00 ms setting to 0 across the rev range, which seemed to stop it stalling. However, the idle is still misfiring, which means unburnt fuel ruining my cats, so I set it to idle on petrol. This made it stall again, so I changed the 2.5 ms from 500 - 1500 rpm to 0 too. Great! It will now idle smoothly on petrol and not stall!

Still a bit lumpy at low loads though...

Any thoughts??

I do have a set of working Magicjet injectors from a previous car - if there is a way to make the Magicjet ck8 file work in the AEB software, I could fit those?

One thing I don't have is the O2 sensors connected to the LPG ECU - I think I should connect these...

I'm not too impressed with the AEB software TBH - I had (and still have) a KME ECU from 2008-ish, which I fitted myself, the software on that let you see how the petrol map compares to the gas map, on the principle that you should adjust your enrichments so that the pulses the car ECU sends are the same on gas as they are on petrol. I don't see that you can do this on the AEB / Romano / King software, you just have to fiddle till you get lucky... The only benefit I see is the idle-on-petrol option. I'm actually thinking about cutting out the AEB and Ultragas bits and fitting my old KME ECU, evapourator and magicjets. Or splashing out another £200 for a new KME ECU from Alternative Fuel Company, where I bought my first kit.

Sorry for the long post, just wanted to give the whole story...
Ross

[mat_fenwick]

the software on that let you see how the petrol map compares to the gas map, on the principle that you should adjust your enrichments so that the pulses the car ECU sends are the same on gas as they are on petrol. I don't see that you can do this on the AEB / Romano / King software, you just have to fiddle till you get lucky...

An easy way to see if the pulse widths are the same (without any software) is to look at the instantaneous fuel consumption read out on the car's display, on both fuels. Displayed mpg should be the same; try a few different speeds/loads, especially in problem areas.

Bear in mind plugs will look white when running on gas, regardless of mixture so cannot be relied upon as an indication.

[rossjp]

Bear in mind plugs will look white when running on gas, regardless of mixture so cannot be relied upon as an indication.

I never knew this... I did take pictures - what's the easiest way to post pictures on here, get a photobucket accound and link to them, or is there a simpler way?

I will post one (they are all the same) and see if people say they look normal...

[rossko]

I think what we'd most like to see is the way the gas injectors have been plumbed into the manifold. Sparkplug tips are not helpful for LPG.

I don't really understand what you are saying about 2.0mS and 2.5mS.

[rossjp]

I'll get some photos of that.

The "ms" I said about are milliseconds, from the map, like the one on the thread I linked to. 2.0 and 2.5 are the lowest on mine (not 1.0 and 1.25 like the guy has on there).

Ross

[rossko]

2.0 and 2.5 are the lowest on mine (not 1.0 and 1.25 like the guy has on there).

Well no, that's a different system on a different engine.

Are you saying you have a misfire when static idling? Let's look into that, easier than tracking down transient problems.
Allow to idle on petrol, when hot, for a couple of minutes. Note petrol injector times.
Switch to gas, allow to idle, note both petrol and gas times.

[rossjp]

Misfiring on static idle, correct.

I did that, they were at around 2.5 - 2.6 ms on petrol, I changed the trim in that area (the 4 'boxes' the dot was floating between) such that the the "petrol ms" went to 2.5 - 2.6 ms on idle, but it still misfired about the same. I tried in the diagnosis window switching over individual injectors - it seemed that (gas:petrol) when you had 6:0 it was rough, incrementally better till 3:3, then incrementally better to 0:6 (where it runs as smoothly as any car I've heard), regardless of which actual injectors it was. I think the misfiring is random (in terms of which cylinder & bank), but frequent.

One thing, is it normal on the LPG software for it to show the rpm jumping around, when the car revs appear steady? For example, on idle it bounces around 600 - 800 when on the tacho (and from the sound of the engine) it appears steady. Even when cruising in 5th, if the car tacho says 2500, the LPG ECU software jumps around 2400 - 2600 or more. This can't be correct, because the engine speed is locked to the rear wheels though the manual transmission.

[rossjp]

The "rpm signal" box is unchecked, which I guess means that they didn't connect up the rpm wire and the ECU is using the injector signal for rpm. It could be erratic because of the extra "micro-injections" my car ECU is doing to try to manage the steady-state (i.e. idling and cruising) mixture. Another reason I reckon this is the case is that, for example, if you are cruising at 2000 rpm and come off the power, the petrol and gas injections read "0" and the rpm displayed on the software stays the same (i.e. stops jittering around and doesn't fall when the actual car revs are falling). This is because if the car ecu is not injecting, the gas ECU doesn't know the rpm.

Could anyone suggest if this could be a problem? Should the rpm signal be connected up?

[Tubbs]

Tbh i think its a bit off to slate an entire breed of LPG ecu's just because yours doesnt work properly. Which is far more likely down to injector placement or something, you could so easily be barking up an entirely different tree altogether.
Pics under bonnet please. Ive done many a bmw in my time, and they all run very nicely. Based around the same ecu. Different injectors admittedly. And for the record i have never connected up a coil wire on a bmw either. And its never been a problem. If you watch the live data on a scanner you will see the rpm fluctuate but the tacho (fed from the alternator) will stay constant.
If you are worried about micro injection just tick the box and turn it off. Simple as.

[LPGC]

Recently fixed some obvious mistakes on several vehicles from a certain installer mentioned in the thread (not from anyone who's posted but mentioned in the thread). As others have said in other threads recently, shame because they used to do decent installs that didn't have these problems - Same company name, different people doing the installs.

What company's sticker is on the front of the AEB2568? The brand will tell us which injectors can be selected.

You've noticed your Beemer ticks over with around 2.5ms petrol injection. What do those petrol injection figures go up to on cam (4000rpm-ish) at full load? Not sure if they're the same but the Ultragas injectors I've seen look like Valtek type 30, which isn't a very fast opening, linear or great flowing injector - Wouldn't be happy fitting them on most Beemers for reasons related to that 2.5ms tickover which I'm going to explain. Even with those injectors though, we can get you running OK but the system might need to do a petrol addition or switch back to petrol at high loads/revs.... Explanation: LPG injectors need to inject enough gas to properly fuel the engine at full power and maximum revs. At 6000rpm petrol injectors have a possible injection window of 20ms. In this window they must be able to open, flow fuel into the engine and close again in time for the next injection cycle, and because of this most petrol injectors go up to 16ms open duration on an engine that does a bit over 6000rpm. Most engines tickover with around 3m/s petrol injection. There are a few reasons why your BMW might tickover at 2.5ms, including (a) it might tickover efficiently (they do with that forced air tickover system), (b) it might do an extra injection pulse, (c) the petrol injectors might flow more or be fed with a higher pressure than most manufacturers would fit on the same size engine. If c is the only one true out of abc then your maximum petrol injection pulse won't go to 16ms and you won't have as much of a problem with poor injectors if it calibrated differently. LPG injectors that aren't great need to have large nozzle sizes and run at high pressures to be able to inject enough fuel within the 16ms at high loads, but this can mean they don't need to open for as long as the petrol injectors at low loads. For an LPG system to accurately measure gas into an engine, LPG injectors need to open for at least as long as the petrol injectors. But, on top of the last point, if LPG injectors are too slow to open or close, then it becomes difficult to accurately dose LPG into the engine at low LPG injector open durations. If you have Valtek type 30's, they won't work well at low injection pulse times. If the last two points are true, the way to improve matters is to lower pressure and/or reduce nozzle sizes. This might mean the LPG system won't flow enough fuel for top end power, but with your system you can add a petrol addition or it will switch back to petrol when LPG injection time exceeds the injection window time.

'Lambda error' can mean many things. If the car was running ok on petrol, no MIL light before the conversion, then unless the 'lambda error' was due to the lambda probe heater circuit, I suspect you've changed the lambda probes in vain.

You've changed the 2.0ms load figures to 0 across the entire rev range. This won't be correct - If it runs better with the zeroes, I suspect one or a combination of the following: you have the extra injection filter set wrong / pressure too high / nozzle sizes too large / injectors not linear enough for vehicle / wrong injectors selected in software.

Connecting the lambda probes to the LPG system won't change anything.

You mention the diagnosis window. I think that the 6:0, 3:3 and 0:6 that you mention is you switching individual cylinders between LPG and petrol. On the last setting you tried, you turned all cylinders back to petrol.. Since it runs OK on petrol there's no wonder it ran better on 0:6 !

First thing to check: As someone else has said, the first thing to do is check to see where they've installed the manifold injector nozzles (spuds). If they're too far up the manifold, you will always have problems at low rpm, especially if your Beemer has the forced tickover air system.

Second thing to check: A lot of BMW six cylinders (including yours from memory) are managed as two banks of three cylinders - like a V6 they have two primary lambda's. The software should therefore be set to two banks. Being a straight 6, this is sometimes overlooked and the installer leaves the setting at one bank. If overlooked there will always be fueling problems. Check in the 'Lambda' screen for 'number of banks'.

Regarding the MJ injectors, just so we know, what nozzle size do they have (if not sure, what vehicle were they fitted on before)?

What is the set working pressure of the system?

What injectors are selected?

Where is the extra injection filter indicator? Start with enabled and in middle.

Where is the 'acceleration injection enrichment' indicator? Start with fully to right.

A few pointers but more questions - Will need more info to better know what's wrong.

Simon
http://www.Lpgc.co.uk

[rossjp]

I'm doing this on my mobile, so hope it comes out OK...

pictures:

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[rossjp]

Tbh i think its a bit off to slate an entire breed of LPG ecu's just because yours doesnt work properly. Which is far more likely down to injector placement or something, you could so easily be barking up an entirely different tree altogether.
Pics under bonnet please. Ive done many a bmw in my time, and they all run very nicely. Based around the same ecu. Different injectors admittedly. And for the record i have never connected up a coil wire on a bmw either. And its never been a problem. If you watch the live data on a scanner you will see the rpm fluctuate but the tacho (fed from the alternator) will stay constant.
If you are worried about micro injection just tick the box and turn it off. Simple as.

Thanks,

I didn't mean it to sound like I was slagging off AEB, I just meant that the software doesn't seem as intuitivel as the only other one I've used... a bit like if I bought a new iron and it burnt my clothes I wouldn't be impressed, even though the're might be nothing wrong with the iron.

The extra injections box is on the page for obd related controls, which I don't have connected (because my car isn't obd2), will it still work?

[rossjp]

Simon, thanks for your reply, I'll need to wait till I'm on a laptop tonight to reply properly...

[Tubbs]

Heres one of mine...


Ive used straws to eliminate any problems with erratic idle, stalling at junctions, lag between idle and out of idle etc. I have also managed to get all the covers back on and put the ecu in the ecu box. But guess what ? It took me 4 days, i changed the crankcase ventilation valve whilst i had the inlet manifold off to drill and position the straws straight over the top of the inlet valves. I did charge £1250 though.

[classicswede]

Cheap job there Tubbs.

Looking at the OP's pics the install is a mess

ECU not secured
No vapour filter?
6 injectors in line rather they a Y connection
LPG pipes rubbing on inlet manifold
and where did the engine cover go?

A very rough looking job did they actualy map the system of just do an autocalibrate?

[Tubbs]

Honestly im struggling to believe that Edward is prepared to put his name to that. Because i certainly wouldn't let that out the door.
I think its probably fair to assume that the injector spud positions are incorrect. Just judging by the rest of the install.
However that doesn't solve the OP's issues. You need to take it back and tell them you are not happy with it and get them to deal with it. Its not your responsibility. You paid for a job and the job has not not had a satisfactory outcome.

[rossko]

I can't actually see anything there to cause the issues though.
Where the pipes come out of the injectors and enter the engine manifold is crucial, but I can't see that business end in the photos - it is at least in the right area.
This is not the later engine that is really picky about these things, I think there may be something else going on.

Like 'ee says, it should not behave like this and can be made to work better, not just accepted.

[antimony]

Heres one of mine...


Ive used straws to eliminate any problems with erratic idle, stalling at junctions, lag between idle and out of idle etc. I have also managed to get all the covers back on and put the ecu in the ecu box. But guess what ? It took me 4 days, i changed the crankcase ventilation valve whilst i had the inlet manifold off to drill and position the straws straight over the top of the inlet valves. I did charge £1250 though.

I recognise that engine bay!!
15,000 miles since it was converted (10 months ago) and not a single problem






yet

[classicswede]

I can't actually see anything there to cause the issues though.
Where the pipes come out of the injectors and enter the engine manifold is crucial, but I can't see that business end in the photos - it is at least in the right area.
This is not the later engine that is really picky about these things, I think there may be something else going on.

Like 'ee says, it should not behave like this and can be made to work better, not just accepted.

There is nothing stricking there for causing the problem but with a little inside knoledge I would say the cause of the problem is the reducer.

That COPY that is fitted has been the cause of similar running problems on other cars. I think even one or two have posted up on here.

I would ask them to sort out the mentioned problems and change that peice of @!## they fitted for a propper vapouriser.

[LPGC]

In my previous post on this thread I wrote the injectors might be part of the problem, but I had looked at the Ultragas site and seen injectors that look like type 30's, having now seen the install pics these clearly aren't type 30's. Don't know if the injectors fitted are similar to the Romano single ones, someone else might know the specs and real life qualities of the injectors fitted? Anyway Rossjp, I hope I didn't give the impression of too much emphasis on the injectors, should still get ticking over OK even if they're not good injectors (with maybe lower pressure or smaller nozzles etc as said before) if everything else is right. Nozzle position most critical.

Not seen the link Rossko mentioned in a recent post yet (will look next but bit unfamiliar with the forum and don't want to lose the typing!) so this might not be relevant, but it is possible to change the map reference points for both load and rpm on most AEB systems and this would probably be a good idea on a BMW that might do under 2ms on over run and tick over at well under 1000rpm.

All advice and comments from my mate Classicswede, Tubbs, Rossko, Mat_fenwick and myself (sorry if I left anyone out) are all valid nevertheless.

Having seen the pics, not a great install as Classicswede and others have already said. I'm also dubious about the injector nozzles being in the correct position. Maybe the install 'got out the door' before the boss saw it! We see lots of installs with similar singular injectors where the piping is all over the place and un-secured, maybe if an installer thinks they can get away with doing so with injectors they can do the same with other components.

Wrote this while the forum was down, just copied to notepad and pasted in now the forum is back up but don't think anyone has yet pointed out my error regarding injector type fitted.

Simon
LPGC