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PostPosted: Sun Jan 13, 2013 6:09 pm 
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hi marek ,

i have the car running on the ms2 ignition only already , so i know the crank is ok , up until now it has been running on a megajolt for 3 years so its a relaible igniton . i dont understand the 'pattern' reference?

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robert


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PostPosted: Sun Jan 13, 2013 6:49 pm 
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See http://www.msextra.com/doc/ms2extra/MS2 ... ogger.html
and http://www.msextra.com/doc/general/toot ... mples.html

It sounds as though you are well past that stage.

More importantly, you can datalog your car by having Tunerstudio connected and open whilst you attempt to start or run it. View a full datalog of what your ECU is actualy doing using Megalogviewer. The software is free. The VEAL function can even tune your car for you.

http://www.tunerstudio.com/index.php?op ... &Itemid=11

kind regards
Marek


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PostPosted: Mon Jan 21, 2013 4:59 pm 
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thank you marek :)


ok doke , well i have a new lead.... no joy ,tried a xp laptop ....joy! no problem connecting ,so somehow i have twisted the mind of my vista pc till it cannot find its watsit from it doofah ,and must fix that .

service kit for the reducer is here from sunny poland in just 4 days ,and i will get that in and try again .

in case anyone wonders how cold ones feet get in wellies, in a car in the drive ,on snow for an hour with no heating ,the answer is .VERY COLD.


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PostPosted: Sat Jan 26, 2013 4:15 pm 
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well well WELL!!!

it only runs ! :D

i inserted my new kit into the reducer , noticing in passing that the small spring looked a bit rough on the end as if it may have at one time been a larger spring..

then put in on the car ,fired up the xp laptop ,which WILL talk to the ms2 ,and tried to start it , fuel pressure was 15 psi.

bit of a stutter ,then nothing much ,so increased inj time to 2.8s .still nothing ,so started increasing req fule in steps ,got to 20 ,and off she went ,finally got it to run quite responsively on req fuel 17 .

at this point the header tank started to blow off .... odd i thought not hot ...oh oh ,blown head gasket ? bit of investigation later ,lpg in water circuit ,gasket on reducer not sealing .

also noticed fuel pressure had crept up to 25 then 40 psi ,so thats not working either .

so 2 steps forward and 1 step back .

took the rducer apart ,noticed the orange gasket on the water side is slightly textured ,whereas the original is smooth , so either they used some sealant on the original , or this new gasket is poor.

ref the gas pressure ,the small spring that sits behind the gas valve , on my one is terminated by a simple break in the large coiled end ,this creates a tilt on the spring when it has the backplate on it ,is this normal ,or has the end of the spring broken off ? this may explain the creeping pressure rise and there would not be enough force on the pintle to seal the gas .

on the good side , at least i know for sure my injectors work with my resistor pack . :)


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PostPosted: Sat Jan 26, 2013 4:49 pm 
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What are we on here, Prins VSI reducer innit?

Never ever use any kind of sealant on the water gasket, not required.
There is a torque setting for the body securing screws - 7nm from memory. Thats tight but not stupid. Like any circular thing, you need to tighten up in an even sequence.

Sometimes the water gaskets do a wierd osmosis thing - depends on gasket and maybe previous coolant - but you get wet sludge between gasket and backplate. This can corrode pits in the backplate. If a pit is where there ought to be a compressed seal, it leaks. You can clean out fill and flatten the pits with body filler. I've heard of someone making a complete new backplate from flat stainless plate.

The light piston spring is not known to break or corrode, it really only has to hold the piston on its seat lightly. From memory, it should stick out the back about 5mm before the backplate is fitted.

Did you get a real kit or pattern rubbers? The pukka kit includes new brass piston with bonded in seal, new pushpin, new screw-in brass bush. The brass bush needs to be refitted with loctite to seal to the body.
If you still have the old brassware you must take a very critical look at the piston face rubber. You should polish the pushpin and the clean the bore of the bush.

In all cases, you must very carefully clean the bore of the body where the piston runs - I find nonstick scourer and WD40 does good. If there is a large wear step in the bore, the unit's scrap. Difficult to say what's acceptable, apart from if everything is properly refurbished yet it still messes about.

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PostPosted: Sat Jan 26, 2013 5:30 pm 
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a few pics

Image

Image

Image

Image

Image

Image


no idea what the little green o ring is for ...there was nothing like it in the vsi reducer .
you can see the abrieviated spring end .... just look wrong to me ?


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PostPosted: Sat Jan 26, 2013 5:33 pm 
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oh if anyone can help me make the photos a bit less/smaller than pics from the 'land of the giants' that would be good lol.


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PostPosted: Sat Jan 26, 2013 7:43 pm 
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Little o-ring is for the tip of the pressure relief valve next to the gas outlet. The old o-ring will be really squashed into a cone.

The light spring does look wrong; but as said it doesnt need to do very much. Just stretch until 5 or 6mm pokes out the back of the body. Think I'd put the 'good' end against the piston.

No spring fault will cause gas-to-water leaks so you know there's more to it than that, that's something amiss with assembly or backplate. Textured orange gasket is good.

Did you seal in the new brass centre bush with loctite? Else that can seep and cause creeping overpressure. You might need to clean away old loctite from the flat seating area to get a good seal. You do need to be scrupulously clean about clearing any loctite debris away from the piston area.

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PostPosted: Sat Jan 26, 2013 7:54 pm 
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brilliant info ross, thank you .

no i did not loctite the brass valve body , i will do that tomorrow .

i am contemplating a tiny smear ,and i mean tiny , of rtv silicone on the water gasket side .just around the centre boss ...obviously ,the danger is that the sealant will squeeze into the cetre area ,which would not be good !

i will see just how far the spring stick out ,and source a new spring of the same strength from my stores i think .i dont like to think of that sharp spring end digging into the gasket .

i did a rough check for flatness on the back plate , but will do a more thorough job as well ,maybe give it a skim on a sheet of glass , but i dont really want to remove the anodising .


regards
robert


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PostPosted: Sun Jan 27, 2013 10:35 am 
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robertXX wrote:
oh if anyone can help me make the photos a bit less/smaller than pics from the 'land of the giants' that would be good lol.
You need to reduce the size in a bit of photo editing software. If you've got Office installed on your computer it comes with a basic photo editor (assuming whoever installed office did a full install and not just the odd bits you might use) or you can even use Paint. In most editors you would be looking for a Resize tool and drop the images down to something like 800x600 and then use those. In Paint there isn't a resize tool, or there is but it called Stretch/Skew. Open your image in Paint, go to Image, stretch/skew and change the 100% in the horizontal and vertical stretch boxes to 50% or whatever, then save the image before uploading.

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PostPosted: Sun Jan 27, 2013 2:34 pm 
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test .


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PostPosted: Sat Mar 16, 2013 8:23 pm 
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OOPS QUICK UPDATE ,

well it runs , reducer fine, presure responding fine , tickover and slightly higher ok ,the rest very rich .now waiting till the ground gets firm enough in my flooded garden to get it on the dyno and map it . :D


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PostPosted: Sat Mar 16, 2013 10:29 pm 
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robertXX wrote:
tickover and slightly higher ok ,the rest very rich

dare I suggest the injectors are a bit slow to open ... due to the use of series resistors ? :)
Shouldn't matter much, so long as they are all consistent when under-driven, and you have enough flexibility in the mapping to compensate.

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PostPosted: Tue Jun 24, 2014 12:52 pm 
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ok dokey !

well after a mass of delays , I am finally having another go at taking off the mixer ring and activating the ecu malarkey.

observations are .

tickover erratic and poor ,lumpy with a feeling of mal combustion .revving up bit of running on 2 and popping in the zorst.

do some mapping , (and play with changing to simultaneous pulses and also 4 pules instead of 2 . not better at all!)

mapping creates a great improvement, I dropped req fuel by 80% then this gave a greater map resolution ,and more sensitivity to adjustment.

rev well now , one interesting problem is , I have the tickover set fairly high 1400 rpm , with a 275degree cam it should be fine around 900 ,but for ease of adjustements I have it set a little higher .. now, it still has a little stumble at tickover ,so as an experiment , I turned down the gas pressure from 15 psi to 5 psi ( pressures are line pressure after the effect of manifold vacuum is applied .) wide open throttle pressure has gone to around 12 psi.

this seems very low ,but it did give a very smooth idle . maybe the injectors are having a problem with higher pressures on tickiver due to the resistors and the lower voltage from the alternator running slower?


robert


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PostPosted: Tue Jun 24, 2014 6:51 pm 
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I am at 72% ve in the tickover area , and I have now tried:


4 squirts ,adjusting inj open time from 1.1 to 3.3 ,and allowing the tune to adjust .

results were ,around 2.3 to 2.5 worked best ,but tickover would not rise above 1000rpm ,and the adjustment did not cure that .ve numbers were anywhere from 30 to 45 . I think I may have a theory ,and that is that the injectors are too big ? and so going unstable at such small openings .


back to 2 squirts ,and instantaneously up to 1400 rpm tick over as before .

then turned the tick over down to 1000 rpm ,all good. pulse width 4ms ,and req fuel 10.

then went for a drive ,allowing it to auto tune , very smooth , bit hesitant until adjusted but all in all very good . map is populating with numbers in the 70 to 100 range . id prefer the 100 to 140 range but hey it works ..

two things , one is a hesitancy on first second of accel I can't seem to get rid of with the accel adjustment,may be lag in the fuel pressure ..

and the other is if I rev it ,then let it drop it will for 10 or 20 seconds run in the 12:1 afr instead of the set 13.5:1. I adjusted the shut throttle overrun down to 50 % but no effect , I wonder if this is also lag in the vapouriser not dropping the pressure fast enough ..so I have shortened the signal pipe by half .


oh I also checked timing and was 1 degree out so adjusted that too.


all in all ..progress! :-)


oh edit to add static gas pressure is now 16 psi engine not running .


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PostPosted: Wed Jun 25, 2014 9:13 am 
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I don't understand most of the megasquirt terminology.

In a regular conversion, 16psi differential pressure would be considered a little bit pansy, but is in the right area. You shouldn't really be suffering much bad effect from machanical regulator lag (but I did point out pages ago there was a reason commercial systems have pressure sensors ;)

Lag on pickup can be down to simple mechanical issues about where the injection points are.

The type 30 valtek injectors you are using would normally have a minimum opening time in the 3.5mS area. That means if you let idle times get below that, it all gets rough and unstable.
What we cannot tell is if your injectors can actually achieve even that - I'm guessing they are still resistor driven, not peak-n-hold? This will compromise the minimum time - you might assume 4.5mS to begin with.

In an installation, if we run into the minimum time issue, the action is to reduce injector nozzle size. Effect is like reducing petrol injector size.

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PostPosted: Wed Jun 25, 2014 10:45 am 
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hi rossko ,

yes I think the injectors needing to be smaller to run 4 squirts would figure ,it also follows that dropping the pressure will allow me to use longer pulse widths ,and get a bit more consistency to the idle area .

the experiment was to run 3.5ms inj opening time ,then switch to 4 squirts and gradually lower ot till it ran the same as with 2 squirts ....never worked !
I went from 1 to 4 ,and not a chance of the smooth two squirts running .so just went back to 2 squirts and 1.1ms time . accordin to the megasq manual , one should subtract closing time from open time to get the correct figure ,so that does actually work out .

im pleased 16 psi is not totally @!## !!

the ecu will auto adjust to make its mixture correct as I drive ,so that's handy , I have to see how the cold start warm up will work today ,then get it on the dyno and map the higher areas .

robert


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PostPosted: Wed Jun 25, 2014 10:58 am 
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I don't know what 1,2,4 squirts means. Banking/Sequencing I guess.

You haven't a chance of running these gas injectors at 1mS actual pulse. Gas injectors are significantly slower than liquid injectors because they have bigger internal parts. But I do not know if a "megasquirt 1mS" means 1mS + some arbritary opening time.

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PostPosted: Wed Jun 25, 2014 1:02 pm 
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ah gotcha ,2 sqirts per cycle ,or 4 squirts pr cycle .so 4 sq would halve the pulse width because it fires twice as many times .so on my engine 4 sq would be a pulse width of 2ms ,instead or 4ms with 2 sq.

the megasq 1ms I am talking about is the opening time ,minus the closing time .this is then added to the inj duration .


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PostPosted: Wed Jun 25, 2014 1:14 pm 
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These injectors have an opening time in the 2-3mS league, when driven as intended. If you are using series resistors, you should allow more. I reckon you should be looking for minimum total pulse duration of >5mS

Can't see any virtue in firing 4 times per cycle;
a) you'll just eat into available time at high RPM wasted in multiple opening/closing times.
b) you'll introduce more error and variation as opening+closing times become a bigger proportion of total duration per cycle.

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