Reasons for EFI

[aludden]

Unless I missed it, it would be nice to have a sticky in this forum (and the other mods as well) that explains the reasons for doing them. Not a flame war, but just a short explanation of what you want to accomplish. Especially for those of us that are not so technical. :-)

Thanks!
Alex

[opethmike]

My main reason for doing it was simply to see if I could do it. A hell of a "what if" to take on, but I am a little bit of a maniac.

Some of the benefits of EFI:

Fine grained tuning of fueling (and ignition, if you choose that route)
This also lets you get the very most out of any current or future performance mods
Better fuel economy and throttle response when tuned properly
A more accessible engine bay, depending on the intake manifold chosen

[Spittybug]

No more K-jet issues such as:

Hot start (or not as is the case) - no need for accumulator
Deteriorating O-rings
Sticky idle motors
Cold start injectors
General age and condition of hoses
Cost of all the parts (and future availability)
Complexity


Reduces weight, looks cool and lets you make changes at will without even opening the engine compartment. All done with a laptop.
....and all of the things Mike said.

[opethmike]

Reduces weight, looks cool and lets you make changes at will without even opening the engine compartment. All done with a laptop.
....and all of the things Mike said.

Weight is a good point. My particular set up saved me approximately 30 pounds.

[AdmiralSenn]

What they said.

For my part, my K-Jet system was just flat out not working. All the invidivual parts worked (I sold them to different buyers and apparently the pieces all worked on everyone ELSE'S cars...) but not as a system. I figured it was marginally more expensive to build a complete EFI system than to build a new K-Jet system.

My car has had extensive modifications performed to it by previous owners that made tuning K-Jet nearly impossible. With my MS install I can tune it super easily and I have the flexibility to go for power adders (nitrous, supercharger, turbo, etc) later on without too much fuss.

Even using the stock manifold, access to the engine bay is far easier.

I would also add that the wiring for an EFI system is actually LESS complicated than the factory harness, both visually and functionally. My engine bay is SO much more streamlined now than it was...

[Delorean Industries]

Impressive results can be achieved for a fraction of the cost with EFI controlling spark and fuel on a Delorean engine. You can easily on an all motor application tuned properly push well over 200+ bhp without an expensive supercharger upgrade for minimally higher results.

[stevedmc]

Kjet is the reason for EFI (or carburetion for that matter).

[aludden]

Thank you all for your responses! Something else to consider! Right now I just woke her up from a 15 year slumber, and I have spent way more money than I had intended :-)

Hopefully Kyle and I will put her back together on Tuesday and see how she runs!

About how much does an EFI conversion cost?

[opethmike]

That's going to vary quite widely. Some folks have spent as little as a grand; I spent around 1.7k.

[dmc6960]

Yea I'd say there is a nice big range from $1000 to $2500.

[opethmike]

Ultimately, the more you are willing or capable of doing yourself, the cheaper it will be. I racked up my total by buying a ready built ECU, an extension called a relay board, some pre-built cables and pigtails, etc.

[Bitsyncmaster]

One reason to go EFI. It supplies K jet users with a few more spare parts.:hysterical:

[Jeff K]

One reason to go EFI. It supplies K jet users with a few more spare parts.:hysterical:

1700-2500? That's actually a lot better then I thought. What is the toughest part to procure? I'm guessing the proper manifold right?

Jeff

[opethmike]

1700-2500? That's actually a lot better then I thought. What is the toughest part to procure? I'm guessing the proper manifold right?

Jeff

In my opinion, yes.

[dmc6960]

It is possible to go cheaper then $1700, which is why my range started at $1000. However it is also very easy to go way beyond that, up to $2500, which I think is around what DPI charges for an in-shop EFI system. Dont quote me on that though because I cannot find the standalone EFI system on his website right now.

A new manifold is not necessary. You can keep your K-Jet manifold but you'll need to custom make fuel rails. You'll also need to adapt the best ways to attach idle air and the air filter (either a gutted mixture unit or a custom fabricated bend). Getting a complete Z7U manifold system is the simplest in my opinion, requires the least custom fabricating. And if your getting the manifold, usually you can get the throttle body, rails, and injectors to go with it. It'll all be used, and the injectors will probably need a rebuilt/cleaning, but it can the cheapest as well instead of paying someone to fabricate a bunch of things for you.

My initial EFI conversion was sub $1000. Got the complete Z7U manifold, home-built a Megasquirt I controller, new GM air temp and coolant temp sensors, cheapest wideband O2 sensor, did all my own wiring except a premade 12' harness which I split in half with a new bulkhead connector (requires drilling big hole in fiberglass), an inexpensive fuel pressure regulator, and a junkyard TPS.

[Spittybug]

Don't quote me verbatim, but these are pretty close to what I paid to get EFI up:

Peugeot 604 manifold - $80
Custom aluminum manifold adapter welding - $300
Fuel rails - in welding price
6 bungs welded into manifold - in welding price
MSII kit form - $250
Wiring harness - $65
6 19# injectors, used but rebuilt - $80
LC1 wide band O2 - $150
LT1 throttle body, used - $35
Idle air valve - $25
Throttle position sensor - $20
Air intake sensor - $20
Braided fuel hoses - $40
Fuel fittings - $60
Fuel pressure regulator & gauge - $150
3 automotive relays & wire - $30
K&N air filter - $60
Registered version of Tuner Studio - $50

I think that comes out to $1,405 +/- 10% for memory. Granted, the custom aluminum welding was probably a good deal from a new friend, but everything else was sourced ebay/DIYautotune/Smileys/Jegs/pick-a-part. The manifold was definitely the hardest to get a hold of (online junk yard in California I think) and as Jim pointed out and this thread discusses: http://dmctalk.org/showthread.php?2083-Spittybug-Designs-for-converting-stock-setup-to-EFI, it should certainly be possible to use the stock setup with some careful planning.

Additional costs come in if your car has issues that adding EFI exposes. As beaten to death elsewhere, all electricals need to be in good shape and your ignition system thoroughly checked.

If someone were to go the route of using the stock manifold, simply removing the air deflector plate, stay with the stock idle control motor, throttle spool and keeping the stock air cleaner, I'd bet this project could be done for under $1,000. In this scenario you don't really have many K-jet parts to sell however.

In my case, if I choose to, I can sell the idle motor, fuel distributor, manifold, throttle spool, 6 injectors, lambda probe and unit, Idle ECU, cold start injector, frequency valve, fuel hoses, throttle body, air cleaner, W pipe, vacuum delay valve, control pressure regulator, fuel accumulator and an idle micro switch! Looking the major parts up on the DMCH site (no hoses, clips, nuts, bolts, brackets.... just components), they would cost ~$2,947 new. I could give a pretty good discount on them and still pay for the EFI system outright. It all depends what you want.

Personally, I don't see my car EVER being able to command any kind of huge some of money even if it were all original. Too many of you 7000+ other owners have kept them stock and maybe even hermetically sealed them! EFI reliability and flexibility is the way to go so long as you don't have an overzealous inspector who tries to ensure that every car's fuel and emission systems have not been modified, even if exempted from testing. I think it is that remote possibility somewhere in the future that prevents me from immediately selling all the K-Jet parts.

FYI, the code continues to be enhanced. I'm about to load up a beta version that has added increased functionality for idle adjustment. A/C pops on at idle and the car will automatically adjust the timing/fueling to boost the idle up to accommodate. Fun stuff and arguably economical to do, especially if you can sell your K-Jet. With the growing amount of experience from several of us who have done it, YOUR adventure should be a lot easier than those of the undocumented trailblazers!

[Jeff K]

Don't quote me verbatim, but these are pretty close to what I paid to get EFI up:

Peugeot 604 manifold - $80
Custom aluminum manifold adapter welding - $300
Fuel rails - in welding price
6 bungs welded into manifold - in welding price
MSII kit form - $250
Wiring harness - $65
6 19# injectors, used but rebuilt - $80
LC1 wide band O2 - $150
LT1 throttle body, used - $35
Idle air valve - $25
Throttle position sensor - $20
Air intake sensor - $20
Braided fuel hoses - $40
Fuel fittings - $60
Fuel pressure regulator & gauge - $150
3 automotive relays & wire - $30
K&N air filter - $60
Registered version of Tuner Studio - $50

I think that comes out to $1,405 +/- 10% for memory. Granted, the custom aluminum welding was probably a good deal from a new friend, but everything else was sourced ebay/DIYautotune/Smileys/Jegs/pick-a-part. The manifold was definitely the hardest to get a hold of (online junk yard in California I think) and as Jim pointed out and this thread discusses: http://dmctalk.org/showthread.php?2083-Spittybug-Designs-for-converting-stock-setup-to-EFI, it should certainly be possible to use the stock setup with some careful planning.

Additional costs come in if your car has issues that adding EFI exposes. As beaten to death elsewhere, all electricals need to be in good shape and your ignition system thoroughly checked.

If someone were to go the route of using the stock manifold, simply removing the air deflector plate, stay with the stock idle control motor, throttle spool and keeping the stock air cleaner, I'd bet this project could be done for under $1,000. In this scenario you don't really have many K-jet parts to sell however.

In my case, if I choose to, I can sell the idle motor, fuel distributor, manifold, throttle spool, 6 injectors, lambda probe and unit, Idle ECU, cold start injector, frequency valve, fuel hoses, throttle body, air cleaner, W pipe, vacuum delay valve, control pressure regulator, fuel accumulator and an idle micro switch! Looking the major parts up on the DMCH site (no hoses, clips, nuts, bolts, brackets.... just components), they would cost ~$2,947 new. I could give a pretty good discount on them and still pay for the EFI system outright. It all depends what you want.

Personally, I don't see my car EVER being able to command any kind of huge some of money even if it were all original. Too many of you 7000+ other owners have kept them stock and maybe even hermetically sealed them! EFI reliability and flexibility is the way to go so long as you don't have an overzealous inspector who tries to ensure that every car's fuel and emission systems have not been modified, even if exempted from testing. I think it is that remote possibility somewhere in the future that prevents me from immediately selling all the K-Jet parts.

FYI, the code continues to be enhanced. I'm about to load up a beta version that has added increased functionality for idle adjustment. A/C pops on at idle and the car will automatically adjust the timing/fueling to boost the idle up to accommodate. Fun stuff and arguably economical to do, especially if you can sell your K-Jet. With the growing amount of experience from several of us who have done it, YOUR adventure should be a lot easier than those of the undocumented trailblazers!

Great info - thanks! My friend is the real mechanic who helped me out restoring the car. I'm a software person so that end I should be able to handle that end. My only concern is the fabrication part, I wish someone made that part of it turnkey.

Yes, the starting setting pioneered here are a big plus! That has to save a ton of time..

I bet all the replaced parts can be ebayed for a grand or so total. Again my guess.

Hmmm.. winter project perhaps!

Jeff

[Henrik]

I am reading up on the aspects of EFI and can see that it is illegal to tamper with the fuel injection. No news there but I assume that we Delorean owners can claim an exemption. Is this based on how your car is classified (age, antique etc) or is it based what state you live in? I obviously want to make sure I fully understand this before I go any further.

[hollywood2311]

Kjet is the reason for EFI (or carburetion for that matter).

Best post of the thread!

I'm in the process of selling my car, and can't help but laugh each time some potential buyer gets upset that the car isn't stock in regards to the fuel system. I guess they'll find out the hard (and expensive) way.

[Spittybug]

I am reading up on the aspects of EFI and can see that it is illegal to tamper with the fuel injection. No news there but I assume that we Delorean owners can claim an exemption. Is this based on how your car is classified (age, antique etc) or is it based what state you live in? I obviously want to make sure I fully understand this before I go any further.

I would never condone breaking the law. In Texas, a car older than 25 years old is exempt from emissions testing as I understand it. If the existing system is not functioning properly and is therefore sub-optimal on its performance, especially in the area of emissions, then isn't it one's civil duty to apply modern technology to remedy the situation? A properly tuned EFI car achieves not only fewer emissions and better gas mileage, but also better performance. The intent of the law, as I understand it, is to prevent people from altering their EPA regulated systems to achieve enhanced performance at the expense of emissions, which is not what we are trying to do when modernizing our systems from the outdated K-Jet technology. Each individual user assumes responsibility for his/her own actions and each state has its own laws with respect to modifications, but clarity of intention is important.

My opinion on the subject is to make the right decision based on technical knowledge, laws of your state and good judgement and then remain with a sub-optimal K-Jet system or convert to an old technology carburetor system or a modern fuel injected system.

[Henrik]

If the existing system is not functioning properly and is therefore sub-optimal on its performance, especially in the area of emissions, then isn't it one's civil duty to apply modern technology to remedy the situation? A properly tuned EFI car achieves not only fewer emissions and better gas mileage, but also better performance.

Amen to that. I couldn't agree more with you but if you end up with an safety inspector that is going strictly by the book, you're screwed.


In Texas, a car older than 25 years old is exempt from emissions testing as I understand it.

It looks like you're correct:
http://www.txdps.state.tx.us/rsd/vi/inspection/inspectionCriteria.aspx
I will swing by my inspection place and ask, just to be sure....

[Spittybug]

Henrik, I just looked on the map to find Frisco. I drive up 35 from Houston to Norman, OK on a semi regular basis since my daughter is at OU. With some pre-planning we could see about getting you EFI'd...............

[Spittybug]

My only concern is the fabrication part, I wish someone made that part of it turnkey.

I can do this. Fuel rails, idle air block and brackets to hold rails. Uses the stock intake manifold. PM if interested.