Fuel injection help please.

If I just replace stock injectors with much bigger ones will I be able to richen up the fuel mixture?  
It's an analog system  

In theory, yes, that should work if the system doesn't have any way to know about the extra fuel and compensate for it.  But unless you can make adjustments, getting the actual fueling correct with a change like this won't be easy.  

Not enough info.  Would like to help, but more detail is needed.  All I can say from this is make sure you put in a wide band sensor and guage so you can see what is happening.

In reply to rslifkin :

I have a running XJS  that I'd like to use E85. We know that E85 requires roughly 60 % more fuel than gasoline.  But gains you 10% more power over even racing gas ( maybe more since the compression of those Jaguars is 11.5-1). 
ignition is separate ( good old distributor and coil) So I can just advance the timing to what works and bobs your uncle.  
Alcohol is very tolerant of mixture.  So close is like hand grenades, good enough.  
 

My logic is to get injectors that flow about 60% more and slap them in and have fun. 
Please explain in simple terms that a 5 year old can understand where I'm wrong?  
Yes I know pump fuel can be between 51% & 85% but I have the equipment to tell what I'm working with.  

In reply to porschenut :

That's a good idea of using a wide band sensor and gauge.  I wonder if I could use that to tell how much ethanol is in the gasoline rather that digging out my laboratory equipment.  

In reply to frenchyd :

For E85, it should work just fine I'd think.  Even if it had O2 sensors, they read lambda, so it would still target the same AFR relative to stoich.  

For e85 shoot for 30-40% more injector flow and plan to use an adjustable fpr for fine tuning. 
 

You can make your own ethanol content meter with a baby bottle and some water. 

In reply to Paul_VR6 :

Um, I'm going to have to learn more about this baby bottle trick.

Paul_VR6 said:

For e85 shoot for 30-40% more injector flow and plan to use an adjustable fpr for fine tuning. 
 

You can make your own ethanol content meter with a baby bottle and some water. 

Paul please tell me more about the baby bottle method.  What I have now is a wooden case with glass test tubes, a glass floating scale and a glass thermometer.  
Also adjustable FPR?  I used one to trigger my cold start injectors when I turbo'd my first V12. But it was on or off and I ran the mixture over rich to cover the first two pounds of boost.  It was awful, too crude but because they sold gold palladium sparks plugs at the time I was able to keep the plugs from fouling. Plus plugs are super easy on V12's to change. Right up top with nothing in the way.  
I digress,

The stock fuel pump might if it's in good shape get up to 34-35 psi  ( it needs 31-32 psi to work) so I assume I would need to switch to an aftermarket pump. Not sure how well that would work since I've never done it.  Is it a straight forward pull out the old one and adapt the new one in?  Or does voltage change with increase in pressure.  Would any fuel pump work or should I look for a higher pressure Lucas pump?  

rslifkin said:

In reply to frenchyd :

For E85, it should work just fine I'd think.  Even if it had O2 sensors, they read lambda, so it would still target the same AFR relative to stoich.  

It doesn't have O2 sensors.  It's analog. Not a single micro chip in the whole system. In the 90's Once Ford bought  Jaguar it started to get O2 sensors. And micro chips etc. 

Paul_VR6 said:

For e85 shoot for 30-40% more injector flow and plan to use an adjustable fpr for fine tuning. 
 

You can make your own ethanol content meter with a baby bottle and some water. 

It would be so much simpler to use the 60% figure.  The Six cylinder version of Jaguar  V12 engine uses a 4.0 liter engine which has injectors just about exactly 60% bigger. The slight difference would be easy to adjust right on the regulators.  If the mixture is less than 85% ethanol it's easy to add denatured alcohol to get it to the 85% figure.  
 

Not only that but the Air meter is the perfect upgrade size to feed the intake manifold for racing.  Something AJ6 gets a nice price for.  
 

I much prefer buying junkyard parts to paying an absolute premium. 

Generally with upsizing the injectors you don't want to change with any of the normal fueling "stuff" (MAF, air meters, etc) the injector size is the part that gets you close. I have found most fuel pumps will work OK with an additional 1bar but don't like to go under 2.5bar. If you don't think the pump has the headroom 50% oversize injectors would be my go-to and turn the pressure down to compensate. I don't know what your pump setup is like but just a booster pump like a Walbro inline should be enough to get you what you need. 

Baby bottle method, fill with E85, add some water (know both values) the amount that mixes is ethanol and the part that doesn't is gas. The rest is math that you can easily find on the internet or with the fancy testers. You can do the same with a flask, test tube, etc but the baby bottle is nice bc it's cheap, marked in ml or oz and easy to shake.

In reply to Paul_VR6 :

Thank you. That makes a lot of sense.  I'll do the injector part first and make sure everything is running fine before I put the bigger " MAF"  on.  By keeping it in the Jaguar family everything should be nice and friendly. The Six comes from after Ford Bought Jaguar and I suspect that might be digital   compared to my ECU which is analog.  But a Lucas injector is a Lucas injector, Right?  
The fuel pump is inline so as long as the Voltage matches up a bigger one really shouldn't be a big deal.  

The baby bottle method sounds almost too simple but logic tells me you are right.  How much will already absorbed water after the percentages?  Or is that one of the unknowns?  

I had to look it up. D-Jetronic. It really is analog!

Not all injectors are the same. The big difference you'll want to watch for is impedance. There are basically high and low impedance injectors. You can run low impedance injectors on an ECU expecting high impedance if you add a resistor pack.

Keith Tanner said:

I had to look it up. D-Jetronic. It really is analog!

Not all injectors are the same. The big difference you'll want to watch for is impedance. There are basically high and low impedance injectors. You can run low impedance injectors on an ECU expecting high impedance if you add a resistor pack.

Is there a guide book that talks about injectors?  Now you've got me concerned that Ford might have messed my clever plans up when they went digital on the ECU in Jaguars

My 1987 jag i6 has an o2 sensor.

In case that matters

frenchyd said:

Keith Tanner said:

I had to look it up. D-Jetronic. It really is analog!

Not all injectors are the same. The big difference you'll want to watch for is impedance. There are basically high and low impedance injectors. You can run low impedance injectors on an ECU expecting high impedance if you add a resistor pack.

Is there a guide book that talks about injectors?  Now you've got me concerned that Ford might have messed my clever plans up when they went digital on the ECU in Jaguars

There are a number of references online.

If you already have the injectors just put an ohm meter on them and see what the resistance is and compare that to the ones that are in the car. IF they are close you are ok.  I think Low Ohm ones are are around 1.5 - 2.5 where as the High Impedance ones are in the 8-11 range. 

NINJA EDIT From the Interweb:  If the resistance is between 1.5 and 4.0 Ohm you have low impedance injectors. If the resistance is between 8 and 16 Ohm you have high impedance injectors.

Measure the resistance of the injectors. I thought all Euro were high impedance (12-14ohm) but maybe these predate any knowledge I have. 

Tell me more about the airflow meter. Generally swapping to E85 in this way you DO NOT mess with the engine load measurement at all. If your Jetronic is the kind with the "knob" best get this pig on a Microsquirt as fast as you can. 

In reply to Paul_VR6 :

The megasquirt  is still in the box and while I'm close to pulling the trigger I remember guys on the Megasquirt  web site who spoke a lot more knowledgeable than I, spending over a year getting a stock engine to even run decently, let alone with E85 and boost. Maybe they succeeded but they never came back on and said so. 
 Back when I was still collecting Engines, two came from guys who had given up on getting their car running using a Megasquirt and just gave me the cars to part out. 
I know I can get it running using the stock system. It doesn't seem too big a stretch to add E85. Maybe I should walk and then try to run?  
When I did my Chump car with the Junkyard Saab's  I had a guy Looking over my shoulder and when I'd make a mistake get me going on the right track.  

Keith Tanner said:

frenchyd said:

Keith Tanner said:

I had to look it up. D-Jetronic. It really is analog!

Not all injectors are the same. The big difference you'll want to watch for is impedance. There are basically high and low impedance injectors. You can run low impedance injectors on an ECU expecting high impedance if you add a resistor pack.

Is there a guide book that talks about injectors?  Now you've got me concerned that Ford might have messed my clever plans up when they went digital on the ECU in Jaguars

There are a number of references online.

I tried to look up Lucas injectors and except for a couple of E Bay sales everything got me back to Lucas fuel injection cleaners. 
 

  I'll measure the resistance on mine and next time I go out to Wisconsin stop and measure the impedance on the 4.0  6 cylinder injectors. 
The old 4.2 injectors off are slightly too big but maybe the volume is less since it's for the older engine. 
 

Robbie said:

My 1987 jag i6 has an o2 sensor.

In case that matters

Yes it's a newer design that was adapted to the V12 about the time Ford bought Jaguar.  About 1990. 
Older  V12's lack that sensor.  I know mine doesn't have them but exactly when it was adapted I'll have to check and see

Edit: One source seems to indicate 1986 was the last year for either the 6 EU  or 16 EU  Lucas ECM. In 1987 they went to the lambda feedback.  They also indicated that it was the beginning of the Digital system although not in any way microchip.  
I can do further research if you'd like.  But I'm confused now. I thought you had the old 4.2 cast iron block. But according to this site  the O2  sensor was first used on the 3.6 all aluminum engine of 1987  (4 valves per cylinder that later became the 4.0) 

Proof of concept on the stock injection is possible, but don't expect a lot of it. I did a lot of fiddling to an early MB with the analog jetronic to get it running right. We were still chasing mixture issues when we just put it on a Micro and it's been running great even on a very roughly done tune (wideband O2, lots of trim). I don't know why the V12 is so hard to get running but it may take a little of expertise beyond the layperson to help. That's exactly what I do, and some of the others in the community as well. This just is probably the worst place for a robust discussion as it's not MS specific, best done in the MS extra forum. 

I finally traced down Doug, The Friend who helped me turbo my V12. 
Asked if he'd help me put my V12 on MS  He flat refused.  He had tried to put a Jaguar V12 on MS years ago and it drove him nuts.  He said he felt like he was redesigning the car.   
Doug is a Navy trained electronic technician who I used to go to for insight on how to keep the plane effective.  He was a wizard with a very practical side.  
Following the Navy he went into computers Control Data etc. Today he works under contract with various airlines  resolving issues.  Sorry very skilled.  
He had me take apart  the ECU  and take some resistance measurements etc.  Mine wasn't too bad, on the lower end of variations he's seen but repairing that would entail sending it to England to be torn down to the boards, Re-soldered and re-lacquered.  4 months average turn around. 
So that idea is off the table. 
 

Now it's either MS or carbs. 
  

  

I don't think putting the V12 on MS should be rocket science. Feel free to contact me directly kandpperformance at gmail dot com

Where are you located?