[GoldGT]

This link is NOT for dummies :haha:


(good info though)

You are correct :veryhappy. I used to read the manual while my wife read her book in bed. I must have read it 100 times and I still only have about 90% of it figured out.
Dan on the other hand probably thinks it's like Doctor Seuss :yup:.

 

[wrench459 (R.I.P.)]

injector timing

Go nine teeth in front of the missing tooth...TDC
Jeff's probably fires his GT injector around the same spot.

BTW sequential fuel injection cylinder two injector shown.

 

[First opel 1981]

Missing tooth? I don't have any missing teeth.

I assume the missing tooth is where the arrow is pointed.
And is this a 20ms span?

 

[GoinManta]

Hmmm. A carburetor feeds fuel continually. I believe Bosch CIS fuel injection also sprays fuel continuously in proportion to the air flow sensor position.

Exactly.. They went for simple. As the L-Jet control is very simple, each time coil fires it fires the injector. By firing 4 times in a split second, they sized the jets to be a quarter the size they needed.

Also the INTAKE valve is CLOSED on all but one stroke, and at the speed the injectors are going, it might as well be it really doesn't matter.

Firing sequentially needs a lot more complicated control system. A more intelligent computer, and other sensors, to take into all the factors, etc.. Like we have on modern engines.

Bosch injections, with the L-Jet, Motronic and CIS systems arent what I would consider modern.

As for programming your own computer.. See threads on Megasquirt. I personally prefer the Bosch system, as its simple and inexpensive. Its also a lot better than carb..

 

[wrench459 (R.I.P.)]

The screen is 200ms in length.
There's 10 blocks of 20ms per block.

 

[GoinManta]

IMHO

Megasquirt = NOT for dummies.. and requires a lot of money, and skills, patience and knowledge. Also for a daily driver its only marginally better than the Bosch system. Again IMHO.. I don't think its worth the effort unless its a Very custom, and high performance motor.

Bosch system = Does the job, big improvement over carbs and if parts are sourced from the right places you can do the whole thing for just the price of the Megasquirt computer. For a stock to only mild performance motor, its more than enough and works well.

This is why I wrote these articles:

Info on Opel 2.0LE / BMW 318i system : http://www.opelgt.com/forums/factory-fuel-injection/42962-2-0l-le-injection.html?daysprune=365

Info on tuning it : http://www.opelgt.com/forums/factor.../47065-bosch-l-jetronic-fuel-injection-afm-adjustment-tuning.html?daysprune=365

Info on Bosch systems and theory : http://www.opelgt.com/forums/factor...fuel-injection/45954-bosch-injection-theory-trouble-shooting.html?daysprune=365

 

[GoldGT]

Go nine teeth in front of the missing tooth...TDC
Jeff's probably fires his GT injector around the same spot.

BTW sequential fuel injection cylinder two injector shown.
View attachment 113074

Yup, trigger wheel is 36-1 and missing tooth is set 90 Deg. out front (BTDC), which equals 9 teeth.

 

[wrench459 (R.I.P.)]

injector timing part 2

Cool now that we know nine teeth before is TDC.
Nine teeth after is also TDC so let's add the next injector into the mix.
As shown ~360° of crankshaft rotation.
720° is a full cycle.

Another look with some place markers. Full 720° of crank rotation.

 

[Vincent]

Pardon me for asking, but I'm can't for the life of me figure out why you would want to know any of this information, unless you were planning on designing your own FI computer from scratch.


As I understand it, you are trying to set up your new car's 2.2 block/2.0 head to run, right? You've got a lot of issues to conquer on that car without adding the complexity of adapting an FI system to a Frankenengine like that, plus all the other FI mods. You're perfectly set up to just put a Weber 38 on it and be done with it..........for now. You can always revisit designing your own FI computer at a later date.

As far as all this business of pulse widths, time variables, micromilliseconds, etc., the computer does all that calculating for you based on the sensor inputs.

Pardon me if I'm missing something here............

:thinking:

:veryhappy

.

Personnaly for my first engine build Weber 38 DGAS was the only way to go. I had no interest in FI But I'm always curious about how things work, and these old fuel injection systems are no exception.
I applaude First Opel 1981 for starting up an interesting and educational thread. Even those who have no interests in FI at this time can still enjoy reading this stuff. It's a refreshing to read good technical threads compared to silly pointless social club threads all the time.

 

[wrench459 (R.I.P.)]

IMHO

Megasquirt = NOT for dummies.. and requires a lot of money, and skills, patience and knowledge. Also for a daily driver its only marginally better than the Bosch system. Again IMHO.. I don't think its worth the effort unless its a Very custom, and high performance motor.

Bosch system = Does the job, big improvement over carbs and if parts are sourced from the right places you can do the whole thing for just the price of the Megasquirt computer. For a stock to only mild performance motor, its more than enough and works well.

This is why I wrote these articles:

Info on Opel 2.0LE / BMW 318i system : http://www.opelgt.com/forums/factory-fuel-injection/42962-2-0l-le-injection.html?daysprune=365

Info on tuning it : http://www.opelgt.com/forums/factor.../47065-bosch-l-jetronic-fuel-injection-afm-adjustment-tuning.html?daysprune=365

Info on Bosch systems and theory : http://www.opelgt.com/forums/factor...fuel-injection/45954-bosch-injection-theory-trouble-shooting.html?daysprune=365

MY two cents
Unless your going for a period correct car the old, simple, Lame-jet system is
worthless.
Try putting a non-stock long duration camshaft using the above mentioned.
It will drive you crazy.
The lack of tuning ability read injector pulse after the exhaust closed event is a killer.

 

[GoinManta]

MY two cents
Unless your going for a period correct car the old, simple, lame L-jet system is
worthless.
Try putting a non-stock long duration camshaft using the above mentioned.
It will drive you crazy.
The lack of tuning ability read injector pulse after the exhaust closing event is a killer.

My two cents is that your wrong.. flat out wrong and no chart will ever convince me otherwise. I also think more than a few car companies would also think your wrong as a few MILLION Of these systems were installed on cars over roughly a 20 year period.

Some of you guys tend to over analyze and want things PERFECT.. searching for perfection can be as big a problem at times as poor performance. You waste countless hours, and $$$s chasing the "Perfect" setup for that extra little bit of performance.

Where as I, and other average Opel owners, just want a reliable system, that starts the car with the first turn of the key, has around town responsiveness, and gets a little better MPG than stock. The average Opel owner will at best will upgrade to a 2.0L build, that goes around town at normal speeds and has about 110 HP Max.. The perfect system for such a car is what was designed for the 2.0L in Europe.. the L-Jet system. It's a simple and accurate system, and does its job well on a regular car. Which is what this is and why there are MILLIONS installed all over the world.

In any case, my experience is that it is a VAST improvement over the Carbs.. is it your $2000 MEGAQUIRT system that you hand fabbed, and spent countless hours on. Not to mention the charts and countless nit picking of the smallest detail. No its not..

But compared to 32/36 DGEV or a 38DGAS.. its head and shoulders above in performance.

I mean seriously, how many know what your talking about half the time, much less what a long duration cam is.. and add to that, even install one..? MUCH less I would gather than will buy a set of 2.0L pistons and valves from Gil to rebuild their old tired block.

Oh and as for the not able to adjust it.. Did you not watch my videos.. You can adjust it in a multitude of ways, most importantly the AFM tension can be adjusted and the fuel pressure. Will it hook up to a computer and get you a pretty chart..? No.. But I don't need a flipping unreadable overly done chart to tell me the car runs better.

 

[wrench459 (R.I.P.)]

...

In any case, my experience is that it is a VAST improvement over the Carbs.. is it your $2000 MEGAQUIRT system that you hand fabbed, and spent countless hours on. Not to mention the charts and countless nit picking of the smallest detail.

mega-jolt ignition system
EEC-IV fuel system..not the squirt...... Fopel
Two stand alone systems working together.

 

[GoinManta]

mega-jolt ignition system
EEC-IV fuel system..not the squirt......
Two stand alone systems working together.

:dunno: what any of that is... or how much it costs, or what REAL Improvement you get over stock..?

I guess thats my point.

 

[wrench459 (R.I.P.)]

...

I guess thats my point.

Why do people climb mountains?
When they get to the top...ask them if it was worth it!
HEE HEE HEE it's all down hill from here.

 

[GoinManta]

Why do people climb mountains?
When they get to the top...ask them if it was worth it!

Actually HERE IS my point.. Average Opel owner, that has a good local machine shop and enough knowledge to be dangerous, can take 60 HP low compression with touchy 32/36 and SIMPLY upgrade to a plain 110 HP 2.0L Build and add L-Jet and see an improvement that is night and day.. It's also reliable, and runs like a modern car.

In your situation, you add another $4000 worth of mods and custom EFI stuff and you get 10 more HP, and a TINY bit of improved throttle response.. but also get a car that is touchy and a PIA..

Its like you want to bad mouth cost effective bang-for-the-buck solutions. :nana:

BTW the thread is "Fuel Injection for Dummies", Not Fuel Injection for those with a million charts and decades of experience in fuel injection.

 

[wrench459 (R.I.P.)]

First Opel 1981 asked a question
and I tried to answer it the best way that I know how.

Yes I know which place this ? was posted "Factory Fuel Injection".

I couldn't help myself :lmao:

 

[GoinManta]

First Opel 1981 asked a question and I tried to answer it the best way that I know how.

That goes without saying.. :haha:

As you even added charts.. :lmao:

 

[RallyBob]

:dunno: what any of that is... or how much it costs, or what REAL Improvement you get over stock..?

I guess thats my point.

Charles, his point, near as I can tell, is that the L-Jetronic will flat-out not run worth a DAMN on anything resembling a real performance cam. I've been there, done that. You can't compensate for the increased overlap, no matter how much tweaking or fidfling you do with the OEM components. I've seen engines melt down because of this. When the airflow meter is flapping at idle, it's annoying as it goes from lean to rich to lean. But when you max out the AFM, enrichment stops. And I've seen plenty of Opel engines burn valves and melt pistons accordingly.

The L-Jetronic might be perfectly adequate for your needs, but not everyone has your specific combo. I know that nothing I've built in the last 20 years will run on L-Jet.

 

[wrench459 (R.I.P.)]

Bob when you "peg" the MAF,AFM nasty things happens also.

 

[The Scifi Guy]

Okay, Bob, now on that point and pertaining to FO81's specific 2.0 head/2.2 block, do you think that L-jet could adequately handle his poorly breathing head for that size block?

:thinking: