EFI made easy for the PRV... maybe??

[Christian Dietrich]

+1

Only problem I've ever had with my fuel system is when my (old style) FP disintegrated inside the fuel tank. I then replaced it with DMCH's combo unit (after a good cleaning). No problem since (that was a couple years ago when they first came out, I think).

Thomas

...

Oh I agree! It all starts in the tank and changing to the new combo is far better than the original style and I think even back in 1981 they could have had a better system. I have the combo unit also but only had it for a year so far and love it!

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[dn010]

Check the EFI section of the forum, you might get some ideas from what others have already successfully done.

[louielouie2000]

Thankfully it seem like the DMC venders are working on a EFI kit. Which is probably going to be the safest bet, but god knows how much the venders are to want to change things over.

I've never heard this before. I've only heard about DMC-Texas sourcing a modern EFI engine for their upcoming replica cars, which can also be installed in vintage DeLoreans.

Yes, DPI does offer EFI conversion:

http://www.deloreanindustries.com/dpi-efi/

[dn010]

Agreed, I only know of DPI working with EFI.

[opethmike]

For all of the time and money it can cost to modify the fuel injection system, it is going to be better to just do what is necessary to get the stock K-jet system working as it should. If you ever need to order parts or service, the D vendors won't know what to do.

For pete's sake, man. If someone has skill enough to install an EFI system on their DeLorean, they will have skill enough to diagnose the new fuel system. Many of us on this very forum have done that same thing.

[DMCVegas]

For pete's sake, man. If someone has skill enough to install an EFI system on their DeLorean, they will have skill enough to diagnose the new fuel system. Many of us on this very forum have done that same thing.

Yes, but you tell them that, and you'll be branded as a "purist" for simply defending the functionality of K-Jetronic.

In truth, I couldn't agree with you more. K-Jetronic is simple, in as it is already calibrated for the stock engine. Your distributor, warm up regulator, injector sizes, etc. are all pre-configured to work with your engine. All you need to do is test them with a tool to verify they're working within spec, and once done you just set the Air/Fuel Ratio. Something that can be done with a exhaust gas analyzer and a screwdriver. A single screw. Just turn it until your AFR # is correct, and you're done. The rest of the entire system is automatically calibrated. There is no shame in taking your car to a mechanic, so I don't look down on anyone who has someone else work on their car. But if you are unable to diagnose and repair a stock K-Jetronic system by yourself where the tolerances and instructions are provided for you already, EFI is going to be out of your league. Even if you had a bolt-on EFI kit that required no calibration, it will at some point in the future require maintenance and troubleshooting as all cars do. What then?

Personally, I have no qualms at all with EFI. Not a single one. Just as I also have no qualms against someone converting an engine to carburetion. You just need to do what makes you happy. So if tinkering around with EFI makes you happy, or switching to a carb makes you happy, I say you should go for it. Because your reason for doing so is for personal satisfaction. However, if you're looking at another fuel delivery system simply as a solution to your problems, you're gonna be headed for more frustration than you have now.

[Bitsyncmaster]

Actually if your lambda is working, an exhaust gas analyzer would just show you where the mixture is holding (14.7 AFR). So you really need to set the dwell so your centered in the lambda range. That keeps the AFR correct as things change the mixture like altitude and temperature changes.

Now if your running without the lambda (carb or open loop) then the exhaust gas analyzer is the best tool for setting the mixture.

[DMCVegas]

Actually if your lambda is working, an exhaust gas analyzer would just show you where the mixture is holding (14.7 AFR). So you really need to set the dwell so your centered in the lambda range. That keeps the AFR correct as things change the mixture like altitude and temperature changes.

Now if your running without the lambda (carb or open loop) then the exhaust gas analyzer is the best tool for setting the mixture.

That is technically correct...to a point. Which is why disconnecting the O² sensor to force the LAMBDA system into open loop is the 3rd step you are supposed to perform before adjusting the AFR by way of the CO screw as per the Workshop Manual.

That way when you set the AFR it will be dead-center within the LAMBDA feedback loop spectrum of lean/rich. Once complete you plug the oxygen sensor back in to allow LAMBDA to reactivate & perform the fine-tuning adjustments as needed on the fly while driving. Otherwise the system is fighting you to where you tune it with a bias to one side. That affects on-the-fly adjustments where your engine runs terribly with too rich or too lean conditions during it's warm-up cycles, massive elevation changes, or WOT conditions.

This is why I prefer the Workshop Manual's instructions versus just always going by dwell alone. It demands establishing baselines across the board on component functionality & combustion chamber conditions to eliminate as many variables as possible, if not all. The duty cycle of the LAMBDA unit can vary during operation to achieve optimal emissions. So if you're going by dwell alone, you can end up fighting the engine which is counterproductive. Dwell is important to tell you that the engine is running properly, but you have to keep in mind that K-Jetronic is also a modular system. It was meant as a replacement for carbs, and still relied upon kicker solenoids and screws to set idle speeds until CIS was introduced. Then it had LAMBDA as an emission control device to fine-tune tailpipe emissions by independently manipulating the AFR on it's own. That's why you set the baselines, and THEN let the add-on devices (WUR, LAMBDA, etc.) control things as they see fit, instead of basing measurements off of their tampering. That's why the Workshop Manual says to set the 950± RPM with a 2000 RPM test and cleaning of probes, a set coolant temperature, and to insure Duty Cycle is @ 50% when disconnected before CO/AFR adjustments, And then no more than a 5% deviation from mean between 45%-55% with the LAMBDA's operation thereafter to ensure sure proper functionality. But it's all about achieving those baselines first.

K-Jetronic is great because when you install the correct, functioning parts, it only requires a single screw to turn for tuning. Yes, you need a couple of tools, but most you should already have, and it's still just a single screw. The trade-off however is that it does not suffer tampering nor accept compromise when tuning. Precision isn't hard, but it's also something that most mechanics with a "good enough" attitude can have a difficult time coming to terms with.

[dn010]

Hmm. All I do is tell MS I want 14.7 and close my laptop.

That is technically correct...to a point. Which is why disconnecting the O² sensor to force the LAMBDA system into open loop is the 3rd step you are supposed to perform before adjusting the AFR by way of the CO screw as per the Workshop Manual.

That way when you set the AFR it will be dead-center within the LAMBDA feedback loop spectrum of lean/rich. Once complete you plug the oxygen sensor back in to allow LAMBDA to reactivate & perform the fine-tuning adjustments as needed on the fly while driving. Otherwise the system is fighting you to where you tune it with a bias to one side. That affects on-the-fly adjustments where your engine runs terribly with too rich or too lean conditions during it's warm-up cycles, massive elevation changes, or WOT conditions.

This is why I prefer the Workshop Manual's instructions versus just always going by dwell alone. It demands establishing baselines across the board on component functionality & combustion chamber conditions to eliminate as many variables as possible, if not all. The duty cycle of the LAMBDA unit can vary during operation to achieve optimal emissions. So if you're going by dwell alone, you can end up fighting the engine which is counterproductive. Dwell is important to tell you that the engine is running properly, but you have to keep in mind that K-Jetronic is also a modular system. It was meant as a replacement for carbs, and still relied upon kicker solenoids and screws to set idle speeds until CIS was introduced. Then it had LAMBDA as an emission control device to fine-tune tailpipe emissions by independently manipulating the AFR on it's own. That's why you set the baselines, and THEN let the add-on devices (WUR, LAMBDA, etc.) control things as they see fit, instead of basing measurements off of their tampering. That's why the Workshop Manual says to set the 950± RPM with a 2000 RPM test and cleaning of probes, a set coolant temperature, and to insure Duty Cycle is @ 50% when disconnected before CO/AFR adjustments, And then no more than a 5% deviation from mean between 45%-55% with the LAMBDA's operation thereafter to ensure sure proper functionality. But it's all about achieving those baselines first.

K-Jetronic is great because when you install the correct, functioning parts, it only requires a single screw to turn for tuning. Yes, you need a couple of tools, but most you should already have, and it's still just a single screw. The trade-off however is that it does not suffer tampering nor accept compromise when tuning. Precision isn't hard, but it's also something that most mechanics with a "good enough" attitude can have a difficult time coming to terms with.

[DMCVegas]

Hmm. All I do is tell MS I want 14.7 and close my laptop.

But how much other work went into de-installation, fabrication, installation, and calibration for that system to even be up and running before you got to that point?