lpg feed pipe size on 500 bhp engine.

[Gilbertd]

Keihin are usually regarded as the best you can get with matrix a fairly close second. Valtek 30's are about the bottom of the pile. No idea on the BRC though.

[LPGC]

I'd rate them in order fast to slow Keihin Matrix BRC OMVL Valtek. You might get away pulsing Keihin and Matrix down to maybe 1.6ms, BRC maybe 2.3ms, OMVL around 2.9ms, Valtek 30's 3.8ms.. All depending on what pressure you're running at and although they'll start to work OK at around those figures they won't really start to be linear until a good few points above those figures.

The other BRC injectors you mentioned (and some related types such as GFI) seem slower than the Valtek 30s, I had to remove some that another firm had fitted as replacements on a mostly BRC system except the injectors had been OMVL, apparently it had ran OK on the OMVL injectors but not since GFI injectors had been fitted, I had a go at setting it up with the GFI injectors but it wasn't going to happen even though the Jeep 4L straight 6 is a very low demand engine, though maybe if the GFI injectors had smaller nozzles it would have been doable with the GFI's. I fitted a set of BRC 'normal' injectors for Miles (@Morat on forum), recalibrated and that sorted all the problems.

[robertXX]

ok brilliant info thank you simon , so stick the matrix at 0.5 dead time and the brc's at 0.8ms ? its nice to know i have not bought 6 poorly made injectors .

[robertXX]

hi chaps..



Well a week of frenzied activity has ocured , all the wiring is now finished ,barring all the mistakes i probably made , and will have to redo ,there's a sexy new /old fuse box on the

bulkhead behind the seat , and so today i had to actually turn it all on .,Amazingly , it all seemed to work , i ha a wrong input setting for the 2nd wide band o2 sensor , which was

easliy fixed by scrolling up the selection box and realizing that megasquirt in their wisdom gives two choices for the same input port ,and only one of them works !


i cranked the engines to log the crank sensor output , and that allowed me to wire it the right way round .

i then activated the gas supply , and heard the familiar sound of gas leaking ...turned uot to be A) a copper compression joint that had bottomed out B) a pair of flattened o rings on the gas supply elbow on the reducer C) a jumped jubilee clip on the gas rail , D) another copper compression fitting .


so i A) made a new pipe B) fitted new elbow with new o rings C)found an even mankyer clip that worked ...and D) tightened it up ..so all fixed.


then checked my lpg pressure gauges , one was at 17 psi ,, fine , the other was at nuffin , not fine ,i took the gauge off and found the plastic lens was rubbing on the needle , so fixed that and had 17 psi there too .noice.




engine 1...






engine 2 ..






this ones dropped a bit , but that's ok ...its probably seeped out past the injectors which have not been used for a while .


i set up the wide bands ..






i had to reprogram them to put out 10:1 =0 v and 20:1 = 5 volts ...so the ecu will chat happily with them ,and automatically set the mixture to what i want .




the ecu has its little umbilical cord..






which i can tape up and fix in permanently once i know it will all work .




so tomorrow is running car/mushroom cloud day ...



HUSTON WE HAVE A GO !!!!






regards
robert

[LPGC]

Nice one Rob

Reckon the wording on your mixture reading gear second pic up just about sums you up... Mr Innovate! This thread and your other thread have been very impressive and just keep getting better! Would love to be Robin in your Batcave lol.

[LPGC]

Last post intended as a compliment in case there's potential for misunderstanding...

[robertXX]

Oh sorry simon , i completely forgot to say , i'm pretty certain that , if you were in my batcave , i would be robin and you would be obi won .

[robertXX]

also , last saturday was a day to forget , i found the manual/advice on the megasquirt forum ,that a 5v trigger signal would work on a pair of msd ignition boxes was wrong ...so i now have two vw smart coil modules from the scrappy wired in and have sparks , so tomorrow iS....

Huston we have a go PART DEUX !

[Gilbertd]

I wouldn't trust anything with MSD on it as far as I could throw it. I've imported numerous older British cars (mainly Jags and Austin Healeys) from the US that would originally have had a Lucas distributor. The Yanks have taken them off and fitted MSD conversions as, having a sticker saying Made in USA, they must be better. Not one of them would run right until we took the MSD stuff of and refitted a Lucas distributor.... The best one we had was an early Porsche 911 with an MSD Ignition Conditioner connected between the distributor and ignition coil. As the distributor had good ole points, I coukdn't see the point of it as it still had the original coil. Broke the seals and opened it up to find an empty box with an LED that lit up when the ignition was on.

[robertXX]

cRIKEY THATS AMAZING GILBERT, nothing in there AT ALL !..barstards .

i had a old msd6 that came off my courier van , had done 100s of thousands of miles i guess ,then it was kiiled by a freind firing it up with no ht lead in it and it sparked to the primary side ,,then my electronics guro had a go at fixing it , but it seems to be dead ... i also had a procomp 6a box which i got off ebay for 25 quid spares or repair , and it works fine ...but i took it off as well becuase it drains the battery and with the new v high compression the poor starter has a tough enough time as it is , especially with the new injection system needing battery power too .

my tvr has a msd7 box which has worked well since 1990 , and the mini has a msd dis2 which also works well .

[LPGC]

I couldn't see the point

Hehe pun!

[LPGC]

Nearly confused Luminition with MSD there for a moment, I used to like Luminition. Some MS systems supposedly work really well with Ford coil packs but that's talking coil packs not dizzy stuff...

[Gilbertd]

nothing in there AT ALL !..barstards .

I Googled the part number on it and found it no longer available but when it had been, it was only $100 so at the budget end of the MSD range. Still expensive for a red painted die cast box, an LED, a few bits of wire and an MSD sticker though....

[robertXX]

no kidding ...just fraud basically.

[robertXX]

well saturday was another drama laden mess .



injectors on front engine refused to open even with no pressure on them , we are getting a pulse coming back down the injectors switched earth , so there is current going through the oils ,,,could they have sat for ages and be all glued up inside ? is that a thing ? these are the brc ones , so will take them apart to see... if they CAN come apart.


next thing was trying to strobe the car , on cranking the strobe would not flash , so today i try my old sun tester instead .


we did have it stumbling/ running up to 600 rpm on the rear engine , and for the first time ever all the exhaust pipes were the same temperature ..noice.

[robertXX]

hmmm...

https://www.lpgforum.co.uk/viewtopic.ph ... 2&start=20

[LPGC]

More likely to be a thing with BRC injectors than other injectors. BRC systems often use a lube system which injects lube fluid into the gas feed pipe between the reducer and the injectors, so the injectors flow lube fluid besides gas.. and it doesn't seem to do the injectors any good whatsoever. Doesn't even provide even lube distribution between cylinders either, the lube fluid doesn't atomise in the high pressure environment so remains a liquid and simply all goes through the lowest injector on the rail or through the first injector 'hole' it comes to like water dropping down a vertical drain pipe (or can even end up inside reducers depending on whether pipe to injectors runs uphill/downhill), lube systems that pump lube into feed pipes to injectors are probably the most common cause of BRC injector failures and injector cleaner doesn't usually improve matters. Even while they're working and haven't gummed/broken injectors they can mess up fuelling because an injector designed to flow gas will flow less gas when partly restricted with liquid lube. Hopefully you haven't bought a set of injectors gummed by lube fluid! Best idea with this type of lube system is to remove it and fit a normal type lube system.

At least the Prins system which uses gas injector pipes to flow lube does it at the vacuum side of the injector so no lube flows through injectors, but they're another crazy design using a foil sealed bottle which you insert upside down onto a spike which pierces the foil... then you have to try to seal the upside down bottle of lube fluid onto the boss with upward facing spike before the contents spill into the engine bay! Anyone with this type system is better off just making a hole in the top of the lube bottle (erm bottom of the lube container except the lube container is upside down).. so they can leave the container attached and refill it in the usual way - The whole idea of the Prins upside down container setup seems to be to prevent users using other brands of fluid... unless users have any sense lol. In fact Flashlube even make upside down bottles for Prins lube systems now.

But have you tried swapping the electrical feed between the Keihin and BRC injectors to rule out an electrical problem (I know you said you'd metered the electrical feed) ?

[robertXX]

well , would you believe it simon , that channel had blown the 7.5 A fuse ! i had looked at the fuses , but it was not clear it had blown , so yesterday checking the lines for contintuity i found it , and the injectors click perfectly . they obviously pull more current than i expected....on to the next problem .

[robertXX]

it bloody RUNS !

raising fueling ,from 2ms to 8 ms , and getting timing right ,and off she went , and revs n everyfink . most surprising .

[LPGC]

Good! Glad it runs.

Mapping still to do? Usually injection duration is high during cranking but it will have to be lower than 8ms at idle if it's to be able to get rich enough mixture when you put foot down at high rpms.

Tch tch fuse! lol.