Efi?

You asked for an explanation -- here it is:

Nobody hijacked anything.

Carburetors were first mentioned by Owen in Post #13. In that post he made an inaccurate statement about needle valves, which I corrected in the post following. I also used that opportunity to set the historical record straight Re: Owen's conversion. There is more to it than even Post #14 documents -- PM me if you want the whole sordid history.

Carburetors were next mentioned by Steve Rice in Post #19, to which nobody responded.

Carburetors were then mentioned by Ron Pirkle in Post #24 as a direct reference to my conversion. I was not able to respond to Ron's comment until Post #27. Ron replied to my response in Post #28, to which I replied in Post #29.

Then you made your factory incorrect accusation.

Explanation enough?

Bill Robertson
#5939

Very much appreciated. This had been very informative to me and I believe I understand now. For the time being I will stick with my K-Jet as it works perfectly well now, and I believe, with the proper maintenance it will last. Carburetors are truly a "vetted" design, and reliable and understood... and old. EFI is the modern, and the future. Its hard to foresee a future in the automotive industry w/o EFI (my first car was '78 Z and it was EFI). Put simply EFI will go on, carbs (however kick ass and cool lookin') will not be returned to by any progressive auto manufacturer. A DeLorean could be further brought up to times with an EFI conversion, but for the low tech nothing beats a carb. If simplicity is ones goal, go Carb. If modernization is the goal, EFI. But if the K-Jet works... congrats to you. Mechanical fuel injection was clearly abandoned for a reason... less reliable, less efficient. But I digest... Thanks for all the information, anecdotes and perspectives, it was most enlightening.

Why doesn't an EFI user with the original K-Jet manifold at least document his conversion? For an EFI kit to work with the masses, it will need to use a readily available intake manifold. That is why I make my own (I need a dependable supply of intake manifolds. For centralized fuel metering the K-Jet manifold is very difficult to work with, although Byrne Heninger has come up with a way to do it, and a welder who can work with cast aluminum).

Bill Robertson
#5939

I will agree that the engine access is SUPER EASY now. Far fewer wires, far fewer hoses and everything is easily accessible right there - in my case I have to do a little extra work to get to the spark plugs because of the way I mounted my fuel rails, but it's overall less annoying than the K-Jet injectors - I just undo the fuel rail bolts and pop the rail out. Super easy.

As far as the varying installation choices, there are lots of factors that explain why each setup is different. In my case, I had a car that the previous owner had converted to a 3.0 - not an Eagle motor, he had the odd-fire enlarged internally... don't ask. It was very nearly a completely different motor. I'm running Daryl's tune because he had almost the same size fuel injectors (and is also using the stock manifold) but I had to tweak it a good deal to get it running smoothly and not run crazy rich or lean. I figured why replace a bunch of functional components simply to line up with everyone else's builds, when my tune was going to be so wildly different and I couldn't really afford the extra parts anyway? And not everyone has easy access to variant PRV parts, either.

EFI is also nice because you have the option to pursue higher performance builds later. My car came with a nitrous oxide kit that I'll be reinstalling once I replace the fire-damaged components (and once I get Christine completely road-worthy again, of course...). I can monitor the engine and force the nitrous system to shut off under certain conditions (e.g. it won't actuate under a certain throttle percentage, or outside of a specific temperature range, etc). This makes it a lot safer than the NOS + K-Jet system that the car came with, which had no provision to check for a dangerous lean condition, for example. The vast array of wires that controlled the system previously will be completely gone - all the wires I need are already run for the EFI controller, and I can just tap the controller triggers into the MS outputs without needing to re-run everything.

It can be a VERY rewarding and fun experience, and I'd highly recommend it if you're willing to tackle a fairly involved project and learn a great deal. #3416 runs FAR FAR FAR better on EFI, even on a rough tune, than it ever did on K-Jet.

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Originally Posted by content22207

Why doesn't an EFI user with the original K-Jet manifold at least document his conversion? For an EFI kit to work with the masses, it will need to use a readily available intake manifold. That is why I make my own (I need a dependable supply of intake manifolds. For centralized fuel metering the K-Jet manifold is very difficult to work with, although Byrne Heninger has come up with a way to do it, and a welder who can work with cast aluminum).

Bill Robertson
#5939

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Bill, I haven't fully documented mine because it really isn't that different from anyone else's, fundamentally - the ECU and wiring are virtually identical, and those are really the difficult parts. And hardly anyone ever uses the original manifold as there are some good reasons to switch to a factory EFI unit - built in idle control, easier TPS adaptation, better fuel atomization compared to the K-Jet injector holes, and overall a lot less head-scratching and fabrication. The 2.8 EFI manifold is a LOT closer to drop-in than the factory unit - witness how fast Owen went from bare engine to fully running EFI with idle, spark advance, and everything else, compared to my ongoing work. I still don't have idle control or spark control yet because I keep having to fiddle with throttle sensor and air intake issues (though I did just recently solve the intake problem).

I would LOVE to make a production run of conversion parts for the factory manifold (throttle sensor mounts, idle and emissions port manifolds, etc) but I just don't have the time or resources to make it happen. Plus I haven't hammered out the issues with, you know, making them actually work yet.

One of the problems with the EFI conversions is that most are "works in progress" especially if the owner is doing it. You can always tweak it and try different settings, mainly because it is so easy to do as compared to mechanical systems. And if you don't like it it is also very easy to undo any changes. As to Bill, the fact that others mentioned the C word first doesn't mean anyone wanted to know where you got your motor from and why you chose to put a c--b on it. At least on an EFI thread anyway. Getting back to talking about the stock K-Jet, it is VERY limited in what you can adjust which is one of the big reasons to consider EFI mainly because even with the Lambda added to the Jetronic, it is still basically a mechanical injection system. To make any significant changes you have to buy parts. And if you don't like how they work you are stuck with them and have to buy more to try something different. Not the case with EFI. Maybe one day someone will do an EFI conversion and fully document it and make it available. Maybe DMCH will do it and call it a Stage IV?
David Teitelbaum

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Originally Posted by David T

As to Bill, the fact that others mentioned the C word first doesn't mean anyone wanted to know where you got your motor from and why you chose to put a c--b on it. At least on an EFI thread anyway.

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Incorrect:

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Originally Posted by Ron

I'm not familiar with the options then...but thought there was a carb and manifold that would work???

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Bill Robertson
#5939

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Originally Posted by content22207

On a more serious note: the PRV was not designed for K-Jet -- K-Jet was overlaid on the engine after it had already been in production for more than half a decade (even then, the first K-Jet installations did not look anything like the installation DeLorean owners are familiar with).

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Actually all K-Jet intallations have a near-enough identical intake manifold. The only real variations were the idle valve and steel pipes rather than hoses.

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Originally Posted by content22207

To date no two DeLorean EFI conversions have been similar, much less identical, even on the same engine (several EFI DeLoreans are 3.0, not 2.8 ).

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Well, there're 3 cars in the UK running Z7U manifolds, and to date I've shipped 3 to the US, and at least one of them is running permanently.

The major "problem" with EFI is software. But then the main advantage of it is it's infinite adjustability. It's not an upside vs downslide, it's risk vs reward.

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Originally Posted by thirdmanj

Mechanical fuel injection was clearly abandoned for a reason... less reliable, less efficient.

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...than EFI. Let's remember that EFI killed both K-Jet and carburetors off.

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Originally Posted by DCUK Martin

Actually all K-Jet intallations have a near-enough identical intake manifold. The only real variations were the idle valve and steel pipes rather than hoses.

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Actually no they didn't. Volvo put a very different K-Jet intake manifold on the PRV for the four years. Volvo did not start using the manifold you're familiar with until 1979:

Attachment 5407

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Originally Posted by DCUK Martin

...than EFI. Let's remember that EFI killed both K-Jet and carburetors off.

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Carburetors are still being manufactured new in the box for aftermarket use. Ford Triton users have the option of adapting an old cast iron manifold to their modular heads (http://cgi.ebay.com/ebaymotors/FORD-...item4aae6897ef) or installing a completely new aluminum manifold (http://cgi.ebay.com/ebaymotors/FORD-...item4aae689875).

Bill Robertson
#5939

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Originally Posted by content22207

Actually no they didn't. Volvo put a very different K-Jet intake manifold on the PRV for the four years. Volvo did not start using the manifold you're familiar with until 1979:

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Hmmm... okay that's a new one on me. They didn't use that manifold in Europe AFAIK.

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Carburetors are still being manufactured new in the box for aftermarket use.

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Sigh.

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Originally Posted by DCUK Martin

Hmmm... okay that's a new one on me. They didn't use that manifold in Europe AFAIK.

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Ummm, E Series was *ONLY* used in Europe (and Australia).

Bill Robertson
#5939