Wet manifold questions / Batch / Port Injection.
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I'm converting my NA 1380 to injection and the easiest way i thought would be to replace the IDA weber with a IDA throttle body and a couple of large injectors. (630cc)
I'm running Omex 200 on the ignition and thus moved to Omex600 to control the injection side of it.

I'll admit straight away that i spent a long time reading through the posts on here trying to get my head round it all, I understand that there will be some compromises injection v carb and it eventually shuts down my brian when i try to understand it all fully when you start talking port injection etc etc.
As i do understand I'm compromised by only have two injector drivers which just fire 1&4, 2&3. I am looking at cam sensing and sequential with a different ECU as a future option.

So I've had this system running and got a decent idle and idle control and each time working on tweaking the cold start compensation.

However questions arrise..acceleration is pants and it feels massively held back, I thought this was a indicator for it being too rich, but the wideband lambda doesnt agree with that?

The timing was checked on the rollers when it was on the carb and it was fine and drove well, could changing the carb for a TB have made that much difference??

Can the lambda be too far back and affect its reading, normaly i have them just after the Y piece but due to space constraints here its nearer the gearstick.

Mixture imbalance - I'm sure i read that cylinders 1&4 would be weaker than the central ones? This is the opposite of what I'm seeing here, its bad enough that the outer plugs are wet at times, it was the same but not as bad on the weber, have i just got that the wrong way round?

I'm booked for a rolling road session on the 7th April but I've got to get there first.

Any pointers and obvious things to check that I've not thought of yet?

Rich

Edited by Richspec on 3rd Apr, 2017.

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Are you running it in 'semi sequential'? I think you would need to with the ida setup giving two totally separate inlets.

Omex term it 'batch injection' if that's the same, 1+4 inject together, as do 2+3.
I was reading the emerald website this afternoon and DW states this twin point method I'm using doesn't work as well as the single point type, like the SC setup, but that's a negative I'll live with to keep the Ida style.
He also confirmed the point that 1+4 should be weaker, not richer like mine have always been.
I think the way to go would be sequential, twin point using a ECU that could trim the cylinders? Can emeralds ECU do that i wonder? I've seen it mentioned but can't find in the manual how to do it.

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If you are determined to stick with the twin barrel down draught, you might be better using smaller injectors, and batch fire injection which is basically all injectors firing simultaneously every engine event.

Acceleration enrichments need to be tuned by 'seat of the pants'. you need to add a chunk more fuel. a slight lean is ok so long as it drives OK, a little rich is where you need to be. Low rpm fast throttle openings need a lot more fuel, while high rpm fast throttle openings need very little. slow throttle openings don't need much either. Tune it until it feels right.

is that fuel regulator high pressure injection rated?

Ignore that, just looked up the FSE regulator specs, it will go to 5 bar.

Edited by Sprocket on 21st Mar, 2017.

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I've just been running it at idle on a tweaked map (less coolant correction) so letting the garage de fume for a bit...... 0.84 at idle.

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I've read the Omex 600 installation and tuning manual and even downloaded MAP4000. Omex suggest this product is a semi sequential system and alternates the injector outputs. I see no reference to injector settings changing from semi sequential to batch


remember that the A series is paired 1/2 and 3/4.


you might have to wire the two injector outputs together (in essence wiring the two injectors to both outputs) to get batch fire. I'm not sure how well that will work.

yeah, my bad for getting the terminology mixed, see this is why i get confused! :)

I effect i've done as you say, to me it seemed the only way to get the injectors, injecting on the right cylinder when they are split either side of the throttle body, as you say 1 pair on side 1, 1 pair on side 2. I'm about to put the smaller injectors in so will muck about with that tonight for a few minutes (its getting late and its not a quiet car!) and report back tomorrow night. I've got a pic of the plugs after it was warmed up and at idle for a while, yep, lumpy cam etc but all wet or damp, very black, but yet lambda was reporting back 14.1 and a solid 1050rpm idle. thanks for your help :) Rich.

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before you do anything else, you need understand how the ECU is controlling the injectors, first and foremost, then figure out how to configure it for 4 injection events for every engine cycle, whether that is by the ECU configuration, or by the wiring. The best people to help you there would be Omex. Give them a call tomorrow and see what they suggest.

what you have to consider with the wideband, is that it is an average of all four cylinders. It doesn't necessarily mean that all cylinders are the same. what you might be experiencing is a very lean cylinder paired with a very rich cylinder, the average of which is what you see as acceptable. Also remember that a rich miss fire reads as lean, so if your fueling is so rich that it is miss firing, the wideband is next to useless.

ok ta, i'll read up a bit more, it fires up and idles ok on the smaller injectors after a very rough change in the fueling.

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I've just waiting to hear back from Omex on their opinion on what I've done. but i did find this description of batch injection, which is exactly as I'm doing it.
'By definition batch fuel injection references a crankshaft position sensor only. It can identify the crankshaft position, but it cannot identify the camshaft phase.

Because of this, all of the injectors fire each revolution. Two injectors from complementing cylinders will fire simultaneously. Complementing cylinders are defined as cylinders which fire at the same crankshaft position, but at opposite cam phases. Injector firing will be evenly distributed across the engine revolution.

In batch injection there will be half as many driver outputs as there are cylinders (assuming an engine with an even cylinder count).

The hardware requirements to run batch injection are to drive two injectors on each injector driver. For maximum efficiency, each injector pair must be from complementing cylinders. '

Edited by Richspec on 22nd Mar, 2017.

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I know my dad runs the omex 600 on his anglia van. It has a lotus twincam but the one with siamesed inlet so very simlar problems to a mini. We had a job getting it to work at all running on the usual batch firing setup. (charge robbing going on) It's a while ago now and I'm not an omex expert but the solution definitely came by switching to running it in a semi sequential mode. (so the omex can definitely do this) I'm trying to get my head around the differences between the two setups but the only thing I can see is that the lotus had the injectors after the ports spit into two where as your engine has the injectors a bit further back up stream which would probably mask the issue a bit more. I'm sure this could be a very simlar problem.

Omex have suggested 430cc injectors and wiring it one injector per driver.
I've queried that last bit as if you have driver 1 only activating on cylinder 1, well then its cylinder 4 is relying on fuel thats injected when cylinder 3 is fired. I know in the grand scheme of things with an engine turning over at vast rates and injectors squirting away rapido theres always going to be fuel in there, i dunno? its a way of it working but further from the right way than I thought I was?

I'll update with what they say later.

Edited by Richspec on 22nd Mar, 2017.

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double post.

Edited by Richspec on 22nd Mar, 2017.

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Whilst you appear to be getting good advice for a "wet manifold" system as the thread title suggests, your system is more akin to port injection, just with the injectors further up the port.

Easy to sort out with an ECU that allows timed injection and the instruments to tell you what needs adjusting.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Or just do a proper wet manifold, with untimed injection ( or sometimes called 2 stroke mode for more squirts per cycle ) and the injector...or injectors further away from the head.

Surely that will be the easiest method for a wet install ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

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The main issue is not the number of drivers. The main thing is to have the ability of setting the injection timing as a function of load and RPM. And you absolutely need to monitor the inner and outer cylinders AFRs separately in order to know if your injection timing is correct or not. So you need at least 2 WBO2 controllers and sensors.

http://www.jbperf.com/

I must add that while this is what you need for port injection and I agree with Paul that your setup is closer to that than to a single point wet manifold setup, I'm not as sure as Paul that it's going to be easy to sort out.

Your setup will have significant wall wetting due to the injector placement and intake geometry. This will make it difficult to get a tune that will work well under steady state conditions and fast transients (acceleration/deceleration).

http://www.jbperf.com/

A small update, omex got back to me again and having looked at what an Ida throttle body is...' it won't work'..
Sequential port injection it is then.
Parts arriving today :) i can alter the injection angle via the ecu, any suggestions what figure i put in as a start point? Do i have the injector ending the injection 10,20,90??? Degrees btdc?

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