any tips on setting up the lpg map

[zen]

tuning up the car now..v8 supercharged toyota powered 1972 range rover..running king ecu.magic jets..1,5bar gas

tuning the map up for max performance..any tips?running wide band a/f ratio meter..

getting there..but not right yet..am i right in thinking missfire on gas due to being weak?though meter dont show this??

bogging down due to tooo rich..meter does show this!

thanks.

[andy evans autogas]

what size have you drilled the injector nozzles to and what reg are you using??

[andy evans autogas]

if you haven't already then take the inserts out of the magic's and wind the pressure up to about 1.8-2.0 .....also what's the afr doing on petrol?????

[sijones]

I've had backfires and the engine shutdown on me because it was too rich, so wouldn't say just lean would cause backfires.

I had the benefit of fuel trims to get mine right, and took me a number of days of constant tweaking to get it acceptable.

One thing is to note the enrichment on accel, that was full + on mine and it caused problems when engine was cold due to the petrol ecu doing the extra rich when cold, as well as map was a bit rich.

Time and tweaking using the AR meter, maybe get someone else to drive, then switch between petrol and gas to get the map to match.

[Gilbertd]

getting there..but not right yet..am i right in thinking missfire on gas due to being weak?though meter dont show this??

What does your meter show? You do realise that the stoichiometric ratio for LPG is different to petrol? For the correct mixture, lambda=1, the stoichiometric ratio on petrol is around 14.7:1 but lambda=1 on LPG is different, around 15.5:1 if I remember right. So if you are using a meter that is looking at lambda and displaying a ratio based on the lambda reading, it needs to be told what fuel you are running on or it will read wrong.

[zen]

yes i do realise its different on lpg...15.6 i told...

nozzles by the way are 2.5mm...cant get the gas anyhigher than 1.5 bar..vaporiser is the bigas biggy twin ..

i can get the a/f meter to show 10 on boost if i try..far too rich....

on petrol all is fine..spins all four whhels,lsd.s locking up ..fun...

not so on gas,..fine if i feed it in,but boot it and missfires..getting better, but no rolling road dont help..lol

[zen]

i know u is gonna say 2.5mm is too small, but as is the ecu software is causing the injectors too run too rich on over run..just just ok on idle, and thats telling the ecu i running valtek 34.s rather than magic jet.. see my posts in having problems for this...aeb ecu's wont allow a small enough gas injection time for the magic jets....

so increasing the jet size is gonna cause car to never run right off power...

[andy evans autogas]

i know u is gonna say 2.5mm is too small, but as is the ecu software is causing the injectors too run too rich on over run..just just ok on idle, and thats telling the ecu i running valtek 34.s rather than magic jet.. see my posts in having problems for this...aeb ecu's wont allow a small enough gas injection time for the magic jets....

.

and there lies your problem i didn't notice it before i wont go into the technical reason for this but the AEB software doesn't support magic's try a set of OMVL superlight's (the plastic body one's) with the insert's taken out and I'm pretty sure all will be well...........

[zen]

how sure are you on this?

just bought the magic jets...then bought a new ecu .. king ie standard latest aeb cos it lists magc jets on its setup...so now this getting expensive...yes spoke to aeb and they say magic jets are set to 3.8ms lowest etting..far to large when running loads of gas pressure...

you sure on this before i go buying more jets?(sorry u may be super hot on this,but i need to know as not suoer rich ..lol)

could you explain to me why aeb ecu even though it "supports" magic jets infact dont really..

thanks

[andy evans autogas]

you sure on this before i go buying more jets?(sorry u may be super hot on this,but i need to know as not suoer rich ..lol)

could you explain to me why aeb ecu even though it "supports" magic jets infact dont really..

.

i think you'v picked the wrong car there should be something cheaper on the market
ok i can't be 100% sure now but i remember a while ago there being a problem with OMVL when they started using matrix even tho they were listed in the software they just didn't work right at all OMVL then put matrix HD in the firmware and that didn't work either back then i fitted OMVL evolution (similar to superlight's) and the problems stopped.i have personally tried magic's on an old AEB ECU and that didn't work it just fried the drivers for the LPG injectors ,i have since tried magic's on a new king with no luck so i fitted superlight's and all is well .it didn't fry the king ECU but just didn't work properly.however i do fit magic's on a daily basis now with KME and have very little or no probs with them in fact i would have no problem with fitting them to everything
(providing the system supports them )
but don't take my word for it maybe someone else will be along soon with a similar answer????

[tommo2009]

to keep you going on gas, tune the system so it runs well off idle, then just set the system to switch back to petrol when it comes back down to idle. At least you can then keep it running for a while and won't have to spend the money on injectors just yet.

[rossko]

tried magic's on an old AEB ECU and that didn't work it just fried the drivers for the LPG injectors

That'll be about peak-n-hold drive, or rather the absence of it on earlier ECUs (or incorrect injector selection). Trying to drive low-impedance injectors (like Magic Jets) from a saturated drive will result in something cooking up.

[tommo2009]

how about this for a similar answer........... change your king ecu and wiring to kme ???
its a bit more expensive but at least you dont have to worry about it changing back to petrol at high revs

if you dont like the sound of it put superlites on it and it should be better

Why would you need to change the ECU, who says it is going to change back to petrol at high revs, the ECU will work just fine. It just needs a vap that is rated for 400hp and injectors that can cope with it

[zen]

the vap is fine..rated at 380 hp..and i have wacked the pressure up as far as i can...so thats ok..

now i was reccomended the magic jets..but there may be my mistake..and hense i bought latest aeb ecu to run them..except it dont...

now idle is is good...500rpm and min injection timing ok..but on the over run down to idle no good..far too rich

i can set them up in map to totally saturate at any revs..ie too rich anywhere,so atleast they give plenty of gas on power..ie empty 55l of gas in sub 50 miles if giving it some..(ouch)

so...keeping the ecu...but maybe injectors too change....

what too please...7200rpm rev limit..400hp..600rpm idle...

now the ecu is 2568 (aeb) in firmware it has many injectors..but at least the magic setting is pooh..what arev valtek 34's like?i need them to be able to limit the gas flow low down, aswell as be able to give 50hp per injector..

[sijones]

now idle is is good...500rpm and min injection timing ok..but on the over run down to idle no good..far too rich

What amount have you got along the top line of the map.

What you prob need to do is make the top row quite low, then the next below that a bit lower.

If you watch it on petrol and see the opening times while cruising it will most likely be in the middle to top sort of range, so reducing the upper rows will reduce the gas on overrun...

EDIT: am prob a bit rubbish on explaining that, tell me if you didn't get it and i'll try again!

[Gilbertd]

I may have missed something but the gas timings follow the petrol injector timings, right? Isn't it normal to turn off the petrol injectors on the over-run? So how can it be rich, the injectors shouldn't even be opening.

[sijones]

Isn't it normal to turn off the petrol injectors on the over-run? So how can it be rich, the injectors shouldn't even be opening.

Mine goes a little rich on overrun for the first little bit before switch off, but isn't overrun switch off a feature of the more modern ecu's, this is reasonable old so am thinking it's not got that...?

[Gilbertd]

It will initially go rich because the injectors are squirting fuel in as you close the throttle and reduce the amount of air going in. After that, the injectors will inject the correct amount of fuel to match the amount of air, so closed throttle means little or no air which would mean little or no fuel too. I suspect what may be happening in this case is that the petrol injectors aren't shut off completely but the times are reduced to a minimum. Due to the firmware settings in the gas ECU there will be a minimum opening duration for the gas injectors (the cause of half the problems here anyway) so the fact that the petrol injectors are still opening means that the gas injectors are opening for the, firmware controlled, minimum opening time which is still too long.

[rossko]

what too please...7200rpm rev limit..400hp..600rpm idle...

That's a big ask actually.
Many injectors can supply 50bhp ... given enough time to flow the necessary fuel.
At 7200rpm I reckon there's only 16mS available. You're going to need a big fat injector and plenty of gas pressure to achieve 50bhp ... but then you run into the opposite problem (as you have) with minimum flows, as big fat injectors and high pressure make difficulties with delivering small dollops.

So you need a high flow injector with better than usual dynamic range.
If we were starting from scratch, I'd look to Keihin, Hana or BRC injectors. But we're not.

I expect the Magic Jets would do the job if they actually work as claimed, but AEB based firmware appears not to believe the claims. So like the man said, one approach would be to use an ECU that supports different driving arrangements for the MJs - one of the Eastern Europeans.

If it were me, I'd try some Matrix HD544 with the existing ECU, not cheap.

i can set them up in map to totally saturate at any revs..ie too rich anywhere

If you are really really convinced you can get rich at max demand and rpm, then reduce the gas pressure and recalibrate. So as to acheive longer inj times for the same demand. That way there'll be more available 'undershoot' before hitting minimum permitted time.
Re-check at full tilt obviously.

Something to watch for on the laptop is that current software will automatically switch to petrol when desired injector times are bigger than available time, i.e. there's not enough time to deliver gas at high power+rpm. That may well be an acceptable solution for you in fact - and I wouldn't be suprised if it happens already in truth.

[zen]

ok..thanks for input..yes you have it correct..even though petrol times are really low on over run..(1.5ms or less) gas injection times are being kept high by aeb ecu..

so first to drop gas pressure..running 1.5 bar now...so try 1.3??

if this fails then i guess bite the bullet and new injectors....?

dont want to change ecu for other make as that means ripping the wiring loom out etc...