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Just Some Dude in Jersey
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Discussion Starter · #1 ·
Car show season and social gatherings are probably cancelled for the foreseeable future, certainly for the remainder of this year. This has been a dreadful hot Summer and I don't really drive all that much for "pleasure", so why not lay the groundwork for a mod I'd like to do at some point in the future?

I'm thinking that the good fuel economy and low emissions ONLY nature of the Motronic system on my 2.4 is holding back the possibility of more power and even better economy and low emissions of my system, as well as, the potential for upgrades like a larger throttle body, plus the elimination of the primitive, huge, and unsightly Air Flow Meter(AFM). So, it has been suggested that I look into a system such as Microsquirt(The more basic version of Megasquirt) to control my fuel and spark. This system also allows me to adapt Air Density sensing, which is 2 evolutions above an AFM and the next generation MAF(mass air flow sensing) to my system, thereby eliminating any space consuming devices between my throttle body and my filter.

At least I think that's what is possible.

My car is primary used for car shows to show off my handiwork and as a platform for me to perform projects on to keep life interesting as I enter retirement. Power, speed, and aggressive driving has never been something that blew wind up my skirt. I got spoiled by the power and fun of my previous single side draft set up, but I'm a little underwhelmed by the present performance of my new stock 2.4 FI system. This may simply be due to the fact that that my previous engine had so much compression that it should have been using 102 octane race gas. Everything else about my last two 2.4 base engines was the same, except for that excessive compression. Also I was using a side draft, which is made to produce max power, and I'm now using entry level fuel injection and spark control, which was primarily designed for fuel economy and low emissions. I gather that modern fuel injection ECU's can be configured to produce more power and they are more capable of adapting to hardware changes that can produce more power. My present ECU is not very adaptable to those sorts of things, hence, my investigation of the Microquirt system.

It's a car show car and the large Motronic manifold is interesting to look at, plus it's all chromed up. Car shows lean towards cars that look vintage or that have vintage hardware, and the present basic hardware and such fits that bill and should work efficiently enough. But I need adaptability to move it to the next level of performance.

I have wet my whistle with the Motronic system and started to understand fuel injection for the first time in my life and I am now confident enough to try an ECU and hardware upgrade. I've got nothing but time on my hands, so why not give it a try and see what happens?

Below are the introductory queries and responses that have transpired between me and the makers of the Microsquirt system. I will appreciate any comments you feel to make. :)

The email discourse so far in reverse order. Earliest comments are at the bottom, with the latest comments at the top:


According to that document, the ECU pinout is about 2 or 3 pins different from our BMW plug and play - the main difference is the BMW has the crank sensor on pins 47 and 48 instead of 48 and 49. So you could use our BMW plug and play ECU with a few changes to the wiring. Or you could use a MicroSquirt wire in ECU if you are on a tighter budget - our E30 write up should work for this.


How to MegaSquirt Your BMW E30 325i and Other M20/M30 Applications - DIYAutoTune.com


The tune of course would be significantly different, and it's possible the trigger angle setting may be different as well; you'll definitely want to confirm that with a timing light before trying to start the engine.

Matt Cramer
DIYAutoTune Support

On 7/7/2020 6:35 PM, [email protected] wrote:


I talked with my engine guys and he provided me some diagrams. My engine is the 4cyl 2.4 with Motronic. What he sent me appears to be the 6 cylinder troubleshooting guise and schematic, but maybe I am wrong. You will find an altered schematic with colored cross outs in it, this is the simplified wiring schematic I used to wire up the engine. I don't have many of the items on my car, like a computer controlled auto tranny(I have a totally mechnical TH180) nor anti-lock brakes nor any connections to the dash and I deleted the diagnostic wires. My ECU just manages the engine in the simplest possible fashion and wiring complexity has been minimised. Here are his answers to your questions: <<< Send him the Motronic manual it's there. He wants the pinout to the ecu. Also tell him we are like early SAAB and some VW we still use a distributor and coil, but ecu controls spark. >>> This is the link to the troubleshooting guide and the schematics: Leaving Facebook Let me know if you need more data. Thanks, Gordon Payton (See the attached pic of my engine compartment for your enjoyment) On Mon, 6 Jul 2020 14:53:05 -0400 "DIYAutoTune Sales (Matt)" <[email protected]> writes:
Do you have a wiring diagram for the stock ECU? I'd like to check
what
the odds are that our BMW or Porsche plug and play unit might fit.
If
not, you can treat this in much the same way as a lot of BMW
installations, which are fairly well documented. See the BMW notes

(including a list of parts) here:

How to MegaSquirt Your BMW E30 325i and Other M20/M30 Applications - DIYAutoTune.com

The main question is what you'll need for ignition. Does this car
have a
single coil or coil packs, and is the coil or coil pack wired
directly
to the ECU or is there an ignition module in between?

Matt Cramer
DIYAutoTune Support

On 7/4/2020 8:00 AM, [email protected] wrote:
> It has been recommended that I consider your system for converting
my
> Bosch Motronic 1.5.2 fuel injection system on my Opel 2.4 CIH
engine to a
> modern system. It is an Opel National Championship winning Opel GT
almost
> exclusively used for car shows. I don't care about big power, I
just want
> a more self adjusting and adaptable system that doesn't use an AFM
and I
> would like to put a larger throttle body from a 3.0 liter system
on it. I
> would like to convert to an air density air flow sensing system.
My
> system uses a 60-2 external timing gear. Although I work as a
mechanic at
> the Post Office fixing letter sorting machines and have no fear of
> electronics, I have zero experience tuning fuel injection systems
and,
> frankly, little interest in do so. So I need a fuel injection
system that
> can self learn to a large extent and work with my existing TPS,
CPS, oxy
> sensor, etc. and allow me to convert to air density sensing and a
bigger
> throttle body. It would be great if you could provide me with the
air
> density/temperature sensor or direct me to a type to acquire
elsewhere
> that works well with your system and what I plan to do. Basic
running is
> what I hop to achieve with little fuss, whereupon, I could take it
to a
> tuner for fine tuning, or help with tuning it close enough myself.
>
> Can you help me?
>
> Thanks,
> Gordon Payton
> Collingswood, NJ
>
 

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European tuners made over 150hp DIN with the C20NE and C24NE engines stock Motronics, and over 200hp din with the six cylinder C30NE, so I don't think that the Motronic is holding back the power. And a "modern" FI won't make more power on a stock engine unless you change the cam and do some porting to make use of the adjustability. As long as you have a stock engine there isn't much to gain with a new system. It is like in the nineties when countless chip tuners promised 20+ horsepower with only a chip change. I have read countless threads where someone has started a whateversquirt conversion and never managed to get the engine run right. It is of course possible but prepare to spend time and money on a chassis dyno.
 

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Just Some Dude in Jersey
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15,468 Posts
Discussion Starter · #3 ·
I will be happy if it just makes the AFM or a MAF go away. As far as "European tuners", well, they're in Europe and I have no access to them. I have no desire to make this a huge long project with large amounts of research on my part. I will take it to a dyno tuner for final adjustment. They will be familiar with working with this system's electronics, whereas no one here would have hardly any idea how to play around with the Motronic.

If I cannot get it to work correctly I will throw it in the trash and go back to the original system. The approximately $450 worth of system and parts is almost nothing compared to how much I have spent on the car.
 

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Opel Rallier since 1977
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2,278 Posts
The mapping will be the hard part. But if you job that out, then that makes your work a lot less. The tuning/mapping is considerably times more work than the setup and connection, unless you can get a head start with someone else's mapping. OK, I see that the pnp2 version comes with some baseline mapping. That helps. Maybe some of the MS users here can point you to more mapping data???

So are you expecting/hoping for much performance change? Going back to the larger throttle body?
 

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Über Genius
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9,463 Posts
I was hoping you were goi g to go all in and buy the motherboard, sister board flap jack generator, and all the fizz that goes with it.
No, you want plug and play! PHOOEY!!
Here I was going to offer you a once in a lifetime chance to hone your solder skills by building the two systems I have waiting. I was even gonna give you back page credits. But, noooooo.

All joking aside, if you need a relay board, I have a bunch. They're still untested but I have complete confidence they might work.
 

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Just Some Dude in Jersey
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15,468 Posts
Discussion Starter · #6 ·
FO - Ha! Ha! Ha! Good one!

That piece of leaky junk aftermarket throttle body was tossed in the trash. Even Charlie tossed his. They were cheap, so not such a big loss. The same size Opel 3.0 one was not a leaky piece of junk, however, but the bolt pattern didn't match my 2.2 manifold. That could be easily fixed with an adapter or mod to the TB itself, so that's not a problem. I could tell while trying to get it to work that it made the engine perform the way I wanted it to at higher rpms, but neither me nor Charlie could get it to transition off idle properly, even with the Opel 3.0 wedge installed. He tried all sorts of combos of Motronic computers and AFMs, even BMW ones, and nothing would work. But the carrot on the stick for me was how well it worked at higher rpms. So, I'm figuring that a more adaptable control system might get the 3.0 one to work, plus the elimination of the AFM. I can't stress enough how much I hate that thing. It flocks up my whole engine compartment. The expense of a new operating system and air density sensing to eliminate the need for an AFM or a MAF would be worth up to $1000 to me, even if the engine didn't run one bit better, but certainly not worse. IT'S A CAR SHOW CAR. Appearance is EVERYTHING to me. I know you motor dudes just can't wrap your mind around that thought, nor can most "normal" Opelers, but that's how I feel about the car. It's for looking at, I barely give a schitt how fast it goes.
 

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Opel Rallier since 1977
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2,278 Posts
Got it... did not remember that TB being so bad! Yes, once you get the programming ability, you have a shot to make the large TB work. It may take some work to get there. Kinda like putting a bigger carb on..... with enough work it may tune in.

No problem from me with the appearance thing. It 'floats your boat' LOL. Poking out into the front area must be a pain to work on.
 

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I remember a new air fuel ratio gauge kit being mentioned a while ago, just wondering what plans you have for that?
It could tell you a lot 🤓
 

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Just Some Dude in Jersey
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15,468 Posts
Discussion Starter · #9 ·
I'll be doing my A/F meter tests this weekend. I'm sure I'll end up finding a 5 psi range where the A/F doesn't really change significantly and is within acceptable limits. :)
 

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Opel Key Master
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5,289 Posts
This is made from stainless to fit a 1.9-2.0 head, but that could be changed easily.
Ralph designed this for this Turbo engine, and I think he stated he still has the drawings. What I’m saying is it looks like even raising it up, it will fit pretty nicely, and you could always have it made of steel and chrome plated? I may be able to get the plans...but I’m thinking this is similar to what you want? Or you just want to go with an Opel aluminum factory style one?
428099
428100
428101
 

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I'll be doing my A/F meter tests this weekend. I'm sure I'll end up finding a 5 psi range where the A/F doesn't really change significantly and is within acceptable limits. :)
12.4:1 can be a tricky number in my experience, I can be running way rich and the engine feels unresponsive and spongey. In my experience with the CIH, it can use a lot of fuel and stay above that number . Just a heads up about that. You’ve got enough information on your thread about this subject. I’ve learned there’s a lot more to tuning than just the numbers. Let us know how she drives when you get your data. Idle, cruising, all that good stuff.
 

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Opel Rallier since 1977
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If you are using up fuel, it's because 12.4 is RICH. Light to medium cruise ought to be 15-16 for any decent economy. You ought to be in the 12-13 range only at WOT. The Motronic numbers ought to be interesting.
 

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Just Some Dude in Jersey
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Discussion Starter · #14 ·
It's amazing the disparity of numbers that people keep quoting me. You two previous posted guys disagree, RallyBob and Gary disagree with you guys.

My main goal is to not be too lean and burn up my pistons. After seeing the huge amount of carbon deposits in my previous engine after only 8000 miles, I also don't want to be ridiculousy rich. The numbers that everyone has quoted are so wildly swung in all directions that I don't really know what to aim for.

Based on previous discussions, I know that the Motronic is expecting a fuel pressure between 35-40psi. My injectors are "rated" at a little above that. More confusion.

My returnless fuel pump system and/or my test point on the 2.4 Motronic fuel rail appears to be causing a ricochet or cavitation effect within the fuel rail because when I try to test pressure when the engine is running my fuel pressure tester's needle oscillates rapidly at idle over a 5psi range, making it impossible to state an accurate rating. The oscillation dies down to a 3psi range as I increase throttle to near WOT and oscillates at the high end of the previous 5 psi range. My tester does not have fluid dampening inside inside the gauge. More uncertainty.

Now, I'm supposed to remove the vacuum compensator hose when running the tests at idle, but it's a major PIA to remove the line and not F it up in the process of reinstalling, so Charlie and I have come to the conclusion that, at least on my system, it's devices, and configuration, testing with pump on, modulator hose connected, but engine off, should simulate a no vacuum situation. When I set pressure in this fashion, it is dead stable and infinitely adjustable to a fine degree. Is what I read "true" pressure? Who the hell knows. But it's a stable reference point. A STABLE reference point. To me, that's all that matters. It's just a reference point that I can rely on to be dead stable.

Hence, the need for me to run a series of tests at varying fuel pressures and develop a comprehensive chart of my A/F readings while parked in neutral, idling in gear with my automatic, and while driving at varying speeds. Plus I have to make sure that I am at operating temperature of my oxy sensor and near engine operating temperature, which my engine never gets to. Engine behavior and perceived power will also be part of the documentation. It should take most of the morning or afternoon to complete a chart at 2psi intervals.

I will then submit the chart for you .com guys to critique and the much larger Facebook community to critique. You will all, of course, wildly disagree with each other and the whole exercise will be pointless. I'm 100% sure that I will have to disregard all of everyone's opinions and decide that a fuel pressure of between 35 and 40psi has the best average numbers and that from that range I will pick the one that that seems to provide the best average driving characteristics.

:)
 

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Can Opeler
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If you are using up fuel, it's because 12.4 is RICH. Light to medium cruise ought to be 15-16 for any decent economy. You ought to be in the 12-13 range only at WOT. The Motronic numbers ought to be interesting.
15-16 gives awful performance on a GT at any speed cruise. Neither of my GTs will run without lean popping and stumbling issues at that AFR. My 2018 Toyota Tacoma doesn’t even go that lean according the scangauge I have on it (although it could. Nox emissions are the issue at above 16:1)

Touching 15 in an Opel GT is sometimes ok, but if you touch the throttle to go up even a slight grade it’s going to stumble.

Gordo. Set it up for 13.5:1 and test. If you like it keep it there. It’s a good in between. I wouldn’t even bother with leaner than 14:1 with a GT. Not worth it.
 

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Opel Rallier since 1977
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2,278 Posts
15-16 gives awful performance on a GT at any speed cruise. Neither of my GTs will run without lean popping and stumbling issues at that AFR. My 2018 Toyota Tacoma doesn’t even go that lean according the scangauge I have on it (although it could. Nox emissions are the issue at above 16:1)

Touching 15 in an Opel GT is sometimes ok, but if you touch the throttle to go up even a slight grade it’s going to stumble.

Gordo. Set it up for 13.5:1 and test. If you like it keep it there. It’s a good in between. I wouldn’t even bother with leaner than 14:1 with a GT. Not worth it.
Good comments all. So if you tune to 15 and then open the throttle, the AFR does not immediately drop to 13 or lower? It ought to vary instantly with throttle changes with the carb circuits kicking in and out, and the 15-16 is only a light/moderate cruise levels. (70 mph on the interstate is not that.) FWIW, the Chrysler Lean Burn system was set to run around 18:1 at light cruise. Best power is down in the 12-13 range and sometimes that gets interpreted as where it out to run all the time. You can make things run at the different AFR numbers in different operating phases if the fueling system is set up right for the different loading, and I can;t see any reason that the Opel chamber will not burn properly at 15-16 AFR for light loading; the plug way over on one side is the only poor aspect of this design (lengthens the burn time) but the closed/quench area opposite helps that. And if one or more cylinders is a lot leaner than the others, then that will mess things up so there is that.

This link gives a good tabulation of where the AFR is for different operating phases:

Sounds like I need to get the AFR meter on my 1900 Jetronic sooner rather than later and see how lean it's lean 50-85% throttle position range gives. It is not very responsive there but that is a purely function of the FI system mapping.

Where is the sensor on your AFR meter in the exhaust located? Things this inconsistent might possibly indicate some level of instrumentation difference. Or we just may not define the same terms in the same way. And what AFR meter and sensor do you have? I have been using an Innovate MTX-L with the Bosch LSU 4.9 sensor. It has a calibration sequence when first connected to the sensor so that has to be done to get accurate numbers.

And Gordo, remember that the engine has to be well warmed up to get accurate AFR numbers. (This is much longer than the typical O2 heater warmup time, which is usually only 30 seconds or so.)
 

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I’m scratching my head on this one too. What sensor? There are several out there. I just assume that the homework was done.

I was going to post the same SAFR post that MR just did, because what I see seems to agree with that chart. All I can share is my experience. That said, I also believe what the others are saying too. That’s been their experience.
When I approached the subject with Gil, a while back, quite a bit confused on the subject he said that I should shoot for the 14:1’s.

Since I like the best of both worlds and perhaps favor the economy side since I run just fine at cruise with no flat spots in the 14’s,15’s & 16’s.
I WAS extremely afraid in the beginning if I dared to get over 15:1.

If the fuel system is tuned properly once the demand increases enough it’ll drop you down into the 12’s, 13’s whatever, no holes in anything that I can see. 😏
 

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Opel Rallier since 1977
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It's not going to need to run at one number, and if the tuning is set to maintain one number at most operating phases, then it is just wasting fuel in some operating phases with the normal variety of street use. The 'one number' needs to spec 'at what operating phase/condition': Light cruise? WOT? 25 mph in 2nd gear on a 3% downgrade?

Some of this is understandable as Tom notes above. If you are road racing, then you're rarely going to be at anything but heavy cruise to WOT conditions, and that will make your tend to be in the 12-13 range for 99% of the time. Makes sense to not care about light cruise economy there... LOL Plus there are sometimes uneven fuel-air distributions, like when you use a single carb and a stock intake so you might have to compromise to a bit richer. Reading the plugs regularly as you adjust the system is the best way to detect a cylinder going lean, and ought to be done in any case. (You could indeed put a sensor in each exhaust runner).

For the FI system with 1 injector per runner, the uneven fuel-air distribution is less of an issue. So I am sure that Gordo will see the AFR varying quite a bit as he varies throttle and RPM conditions.Totally normal for system mapped to make decent power and also have decent fuel economy; you really can have both. Works that way in the carbed world too; always has.

BTW, Gordo, your setting of the fuel pressure with the engine not running is perfectly fine, and is known as 'baseline' setting with no intake vacuum present, and is, as you note, the maximum operating fuel pressure. (That method of checking regulated pressure is in the early Opel Jetronic FSM info.) The pressure will just drop from there during operation, just a hair over 1 psi for every 2" of vacuum increase, when the compensation port is connected.

I can't recall if you have a vacuum gauge in your car already or not, but that gauge ought to be part and parcel of this testing. The vacuum level is the main indicator to you (and to your new planned FI system) of showing engine loading. So you look at that to figure out if you are at light cruise, heavy cruise, etc. Just as pure observational info, on most engines, light cruise in a gear that does not lug the engine is around 13 in of vacuum + or - .
 

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Just Some Dude in Jersey
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15,468 Posts
Discussion Starter · #20 ·
Yes, I have a vacuum gauge in my dash. Since the FI install and my casual driving tendencies, it pretty much stands straight up in the green perfect zone. I never really needed it, except as a fun gadget whose needle would swing when you floored it. It's primary benefit is to let you know that a vacuum leak is developing. A very useful tool on a brand of car whose engines are prone to vacuum leaks.

I don't plan on making this an all day adventure and I can't easily get up to highway speed near my house, so 40, maybe 50, mph will be my max test speed. I'm seeking to test pressure between 35 and 45psi, probably at 2.5psi intervals, so that will make for 5 fuel pressure test levels. Previous driving had shown that I didn't like pressure below 35 and anything over 45 seemed to be wasting gas and not appear to run as "clean". The data will tell the tale and I can decide if more tests are necessary based on what the data says.

I presently plan on leaving the pressure gauge attached when I go driving. I have to drive 10 miles through traffic to get to a lightly traveled road where I can get up to 50mph. The concept of being able to take the readings at one pressure level, then be able to pull over to the side of the road, adjust the pressure 2.5psi higher, hop back in the car, and take the next set of readings would be really great and save me the trouble of driving 10 miles home just to change my pressure.
 
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