Early Bosch fuel injection help please?

Does anybody understand the  early Bosch fuel injection system VW, Audi, Jaguar etc. well enough to fill in some gaps in my knowledge? 

How early?  Djet in the 70s was electric triggered injectors 

CIS in the 70s and 80s was sort of mechanical injectors.  

I suspect Djet . 3 units were used to batch fire the 12 cylinders on A Jaguar  1975-80 

the fuel pump was set to 31-33 psi. 

Djet is fun.  Triggers in the distributor, test with ohm meter for on off.  Temp sensor on the head in a VW cannot read 0 ohms, pressure sensor, low resistance (<100) 4 pins total. Resistance between sets of 2 pins.  Throttle position switch doesn't matter to get it running just works like accelerator pump and sends WOT.  Pump should run for 5 seconds when ignition turned on.  Pressure you are getting should be fine, keep less than 40.

Hope this helps.  If not 

two one 5 three one 7 five three two 8

Randy

In reply to porschenut :

Thank you. My question is more based on ignorance than anything.  

If I were to get a fuel pump that doubled the pressure to the injectors , would that double ( or about) the fuel delivered to the cylinder?  

More than a decade ago I put a pair of used Saab turbo's  on a V12 to get it running I kludged a system up where I really richened the fuel up  and then once more than 2 PSI boost was achieved it triggered the cold start injector. 

As long as I didn’t go past 6 PSI ( about 5500 rpm )  it seemed to work.  Every once in a while I see it still running around.  

But maybe I didn’t have to be so crude? If I use boost pressure to trigger an increase in fuel pressure  with trial and error can I get a working system?  

Pressure is set by the regulator, not the fuel pump.  Switching to a boost-referenced regulator might work.  Won't really know until you try.

D-Jet is really designed to work within a fairly tight set of parameters. Pushing it outside of those parameters can get unpredictable results.

I’m showing my ignorance.  I want a simple way to get the Bosch system to accept turbo chargers.

I started with fuel injection  using Hilborn Mechanical. It has a pump that the faster the engine spins the greater the fuel pressure which  is exactly what the engine needs.  All you have to do is get the main jet right and you’re good to go.  

Older  mechanical fuel injected Corvettes work basically the same while Jaguar”D” types with mechanical fuel injection have a ramp affair and a mechanical pump.  

Using E85 which is mostly alcohol and I know how tolerant alcohol is To mixture strength.  Air density has to change pretty significantly  in order to need a different jet size  when using alcohol  but much more dependent when using gasoline.  

The system will not work well with a turbo.  It is not programmable and doesn't understand boost.  Piggyback injector(s) are a compromise.  Best to scrap the system and go standalone.  I tweaked the system in my 914 with resistors in the temp sensor to make it think the engine was still cold and bumped the pressure up a little.  Had a narrow band sensor, that was all there was back then, and it went full rich on acceleration so the engine ran well but there was very little tuning ability.  Sort of an analog computer.

MegaSquirt it, but it's going to cost more than $14.95.

In reply to porschenut :

You are absolutely right it’s an analog system. Not a micro chip in sight.  I have a brand new mega Squirt in the box  but the fear of programming the system to work  terrifies me.  

I’ve gotten several cars owners have attempted to do something like this only to give up.  These are guys trying to just replace a stock system not add turbo’s and E85  plus somehow make it so I can plug a lap top into it and hunt and peck changes. 

Frankly what I need is a ECM whisperer who works cheap.  I can do work, wire, weld, connect, fabricate,  but I sux at computerisms. 

Time to bust out that Mega Squirt and jump into the new millennium with both feet Frenchy!

In reply to bentwrench :

I have a brand new in the box mega Squirt. I don’t have the knowledge on how to make it speak V12’s with Turbo’s and E85 

NOT A TA said:

Time to bust out that Mega Squirt and jump into the new millennium with both feet Frenchy!

Not by myself!   I’m a delicate old man near my final days 

whine whine snivel snivel. 

AHAHA, all the more reason to get started. So you have time to finish!!!

Don't worry once ya get going on it the kids here will be more than happy to teach an ole dog new tricks. Pretty sure someone from DIY autotune is a regular here.

That’s encouraging. I wish I had a sounding board to run wild ideas by. 

For example would it be easier if I switched the controls, injectors, and sensors etc to GM ?  

Or should I stick with Lucas?  

Back in the day before the factory computers were well understood and easy to reprogram guys including me would use the Cold Start injector from the mechanical fuel injection systems to add more boost to otherwise stock engine management.   You simply get an adjustable pressure switch to kick the injector on at whatever boost level you are starting to lean out.  It is very crude, but did get the job done.  

I can get you all the part numbers if you want, but the pressure switch from back in the day was a simple adjustable unit desgined I think for oil pressure or whatever on old tractors...   it was easy and it did work.

http://www.thedodgegarage.com/turbo_extrainj.html

Heck If you are already using a old bosch mechanical injections system you might already have the cold start injector in the system.   Just kicking it on with boost should support a few lbs of fun

Lucas??????

I'm not as old as you but BTDT! I run from Lucas.

UIn reply to ronholm :

That is exactly what I did more than a decade ago.  Richened it up enough to get to 2 pounds of boost and then used the cold start  injector to get me to 6 psi 

NOT A TA said:

Lucas??????

I'm not as old as you but BTDT! I run from Lucas.

I love Lucas. My MGTD has been running on Lucas since 1953.  I haven’t had any trouble at all in any MG or Jaguar. In fact the stock system still works.  I just can’t get the British and German system to speak to turbo’s and E85. 

frenchyd said:

NOT A TA said:

Lucas??????

I'm not as old as you but BTDT! I run from Lucas.

I love Lucas. My MGTD has been running on Lucas since 1953.  I haven’t had any trouble at all in any MG or Jaguar. In fact the stock system still works.  I just can’t get the British and German system to speak to turbo’s and E85. 

You sir, may be the only one, EVER.

frenchyd said:

That’s encouraging. I wish I had a sounding board to run wild ideas by. 

For example would it be easier if I switched the controls, injectors, and sensors etc to GM ?  

Or should I stick with Lucas?  

Umm... none of the D-Jet stuff is Lucas. All Bosch from Germany.  It's 99.9% likely the entire engine harness is separate from the chassis harness (which may have a good bit of Lucas bits in it).  Very common on LBCs (and a few Swedes) that had EFI added later during production.

In reply to Ian F :

The early Jaguar fuel injection is Bosch.  3 four cylinder sets batch fired,, triggered by the distributor. I think the tops of the units have a Lucas decal on but the bottoms have the Bosch part numbers. 

  Later  Lucas following Bosch’s lead developed their own system,  still batch firing, still all analog.  TWS and Lister both developed their own systems going to Their own designs.

It wasn’t until Ford bought Jaguar  that individual cylinders were fired ( digital control  of ignition began and the distributor went away)  At last the old analog system disappeared  

I was in the same boat years ago, the first standalone install was very scary.  But it worked great. The support and system intelligence now are great.  If you want to install a turbo and get real power and driveability it is the only way to go.  If you want a few more horsepower and worse MPG tweek the Djet.  But honestly if you keep the djet keep it stock.  They have great driveabiilty when they work right and are very easy to troubleshoot.  Except for one thing.  The 914 wire harness was ALL WHITE WIRES!!! So tracking down a wiring issue was true joy.

Bank fire was pretty common with a lot of EFI systems until the 90's.  Hell, a lot of systems were TBI systems. 

Lucas attempting to develop their own EFI system that was little different than an already obsolete Bosch system (Bosch abandoned D-Jet in the early 70's and went to K-Jet): reason 482 of why the British Auto Industry failed... 

If you want a turbo V12 to run reliably, you're going to want to come to grips with MS.  My guess is somebody in the DIYAutoTune world has already done a MS V12.  

porschenut said:

But honestly if you keep the djet keep it stock. They have great driveabiilty when they work right and are very easy to troubleshoot. Except for one thing. The 914 wire harness was ALL WHITE WIRES!!! So tracking down a wiring issue was true joy.

I don't know if I agree with the "easy to trouble-shoot" part, but I do concur when it works well D-Jet is a pretty reliable system - kind of amazing since some of those ECU's are 50 years old.  The harness wiring is all white in the Volvo system as well.

In reply to Ian F :

Yeh, I kludged up a system to run Chump car. But That was with a bit of guidance.  

Taking on Mega Squirt without someone who’s done it successfully is too big an ask. Last time I visited their site the same guy was still sorting out his and his was stock.  Add turbo’s and E85???????? Plus it would be nice to plug in a lap top and change things as required.  

I’ve honestly looked at Mechanical systems and they are very simple and straight forward. Just not affordable.