PEFI (programmable electronic fuel injection) is here to stay and will become a necessity in the future to keep our 914s on the road and I want to be part of that revolution.

Studying the different available PEFI systems and 914/4 engine layouts, they are all very similar in terms of their electrical and harness requirements. So I have been working with other club members (EE’s!) who shall remain nameless for the moment, to develop a universal 914 fuel injection wiring harness specific for the 914/4 or type 4 engine, that can be easily adaptable to most of not all aftermarket programmable electronic fuel injection (PEFI) systems. I have attached a couple of diagrams of our ideas and would appreciate anyone’s feedback, because this harness is for all 914/4 owners and I want it to serve our needs to the fullest. If its not a good solution that will serve most peoples needs, then I won’t make them.

The concept of this harness is clear: Create a PEFI harness that is simple, and adaptable to all or most aftermarket PEFI systems, built of high quality parts and workmanship for durability, and be reasonably priced. I realize it won’t meet everyone’s needs, but it should be a good solution for most. My intent is that it be Plug N Play and take the R&D, pain and expense out of building a harness that most dread. Buying this harness gives you reliability and gets you on the road much faster than having to build your own harness. I know some of the PEFI systems have harnesses available, but they are not the best solutions, they are not complete, and they are not made for the 914, although they can be a good start. My PEFI harness features include:

FI systems – A fuel-only PEFI system would be nearly Plug N Play, which I think most 914 owners will want when their MPS dies, most do not want to fuss with complex systems, but this harness will work for those who do. If someone would package an ECU with preloaded maps for specific engines, the install would be nearly painless. I bet the time to install a simple system could be accomplished in an afternoon if coordinated. If ignition control is needed, then my PEFI harness with additional wires, has the expandability to accommodate your needs.

2-piece harness with a weatherproof main disconnect in the engine bay – This allows the production of a standard engine harness configuration which will universally fit all type 4 engines, 1.7, 1.8 and 2.0L. The ECU harness segment can be made to the length you require, so the FI box can be located in the cabin or anywhere you select. The main disconnect allows the harness to penetrate the firewall and become mounted to the chassis, and also allows easy engine drops. Wires on one end of the ECU harness are long (is 18 inches enough?) and not terminated, so you can hook them up to whatever FI equipment in whatever arrangement you want.

Auxiliary wires – The PEFI harness connects all the standard 914/4 engine mounted FI sensors and fuel injectors to the ECU controls – TS1, TS2, TPS, and Tach. It connects to power and the fuel pump relay at the stock relay plate and to grounds in the stock engine case location. It is convenient to use the stock D-Jet AAR, controlled through the ignition harness, but if you want a fast idle solenoid or even a stepper motor you can have it. The standard harness includes 4 undesignated auxiliary wires for your use which might serve a fast idle solenoid, stepper motor or ignition trigger. If 4 extra auxiliary wires internal to the harness are not enough (it will be for most people), then I can provide as many as you like for an additional charge using a different main disconnect configuration.

TPS – At additional cost, I will provide a new TPS potentiometer with a disconnect and casing, or you can send me your TPS and I will install the disconnect and casing.

Connection hardware - D-Jet hardware is standard (new boots!) so you can reuse the stock FI components. Optional L-Jet connectors can be installed for a small cost increase. The harness can be configured for FI power resistors, or not, depending on your needs.

WBO2 cable – Use the cable from the WBO2 manufacturer and run it separately from the FI harness to keep things easy and protect the WBO2 warranty.

High Quality - The PEFI harness cable is fully cased to protect the internal wiring from chafing, fluid contamination and heat damage. All new, high quality parts and workmanship are used in its construction, this harness does not use any old parts and there is no core charge, although I might buy your D-Jet harness for my D-Jet harness customers. The Tach wire includes a shielded ground.

Price – What might all this cost? I honestly don’t know yet, but considering the parts cost purchased in bulk quantities, and the amount time required to make them, I think I can make them available in the $400-450 range or thereabouts. Is this price range reasonable? If not, where does the price need to be for you to buy one?

So talk to me my esteemed colleagues…and thanks in advance. My intention is to bring these on line in the next few weeks if possible.

Potential FI box layout for simple fuel-only D-Jet replacement system:

Jeff

Harnesses made by you would be great. But, in my opinion it needs to be in a package with the ECU and probably the WBO2 controller and sensor. Even then is there enough of a market to make it work? No one would like to see you or anyone else stuck with product they can't sell.

Fuel only PEFI although welcome may be a little short sighted also because there are people who will want crankfire as long as they are going to the trouble. Add to that distributors are old and worn. I think you would have to include provisions for DIS.

One thought would be to buy preassembled MS kits and program them for stock configurations. To keep costs down the kits could be assembled from components. Possibly a deal could be worked out to buy them at a discount. WBO2 would probably have to be bought at retail price. One could collect the program files and burn them to CDs. If ECU's were bought in quantity maybe named brand brains could be used (longshot I think).

People would still have to realize that optimum tuning would require tweaking at the least and probably dyno time.

I would suggest that a WBO2 be manditory because otherwise the program is hit or miss. There are just too many variables with our cars and their age.

The problem with providing parts specific to the 914 is that the market is so small it will only support cottage industry and therfore there is no cost reduction as a result of quantity. I have a hard time seeing any opportunity for profit in this. Provided the people putting it together were satisfied with doing it for the greater good and maybe a little money, it might fly. But, if there had to be minimum quantities of supplies purchased and money at risk, the greater good may not be enough compensation.

As much as I love these cars, it's tough to see anything positive in them from a business point of view.

Dave

Thanks for taking the time to comment Dave, most especially coming from you.

I considered making full packages of ECUs, harnesses and all the goodies, but there are endless variables. Everyone wants something unique to their engine configuration, ECU choice, ignition options etc. The investment needed to stock and configure various ECUs and all the other requirements is substantial and more than I am interested in doing right now. But people still need a good harness, and thats my Espesh-E-Al-Ity.

The wiring harness requirements for all PEFI systems is similar enough, that one common basic design can be made to fit most or all PEFI systems to the 914/4 with only two easy-to-make variations: 1) Harness length to support different ECU locations, and 2) Enough undesignated wires to offer the flexibility to connect all the needed components together for unique requirements.

By PEFI I am generically referring to all the systems I have looked at and that interest most 914 owners: MegaSquirt, Microsquirt, Emerald, SDS, Perfect Power, Autronics etc.

Let me ask the rhetorical question that no one here has really discussed:

Besides all the other decisions made about a selecting and tuning and installing a PEFI system, how much time does it take and at what cost does the wiring harness take to fabricate? Its a hidden cost, because of the learning curve and special parts acquistion. What was the quality like when completed? I bet those that have actually built a decent harness will realize the harness is a major cost item in terms of hours and dollars. My harness will provide a cost effective and high quality solution for some, hopefully many 914 owners converting to any PEFI system.

The harness design I am proposing in its simplest form is fuel only, and has 4 additional undesgnated wires for optional upgrades. Its a direct D-Jet (or L-Jet for 1.8 owners) replacement so if your MPS dies, then swap in this cable, an ECU, a TPS, a WB02, tune it and its play time. Use the stock relay board for power and fuel pump control, the stock AAR and distributor, and the stock fuel injectors and sensors - I dont see these parts as part of the main problem of a disfunctional stock FI system for most 914 owners (its the MPS if you have to ask). We need to be mindful to minimize 'scope creep' for the swap to PEFI. If someone were to make premapped ECUs available, (perhaps for stock engine configurations) then the swap would be a bolt in, Plug N Play. I would love to work with someone willing to premap the ECUs for a turn-key system.

If someone wants crankfire or other ignition control, a fast idle solenoid, a stepper motor, and other options, I can easily put a few more wires in the harness to make it work for them. The basic harness configuation does not need to change.

What is DIS?

I have been making the 914/4 engine bay harnesses now for about 7 years. I do make a small profit on each harness to keep the venture viable, but its not enough to put my kids through college, which has never been my intent. If it was not viable, I wouldn't spend my time and energies doing it.

It seems to me that people do rebuild motors and try to save 914's. Programmable fuel injection is the way to go, IMHO and that of a friend who is a long-time P car wrench, and who would want to put the old, crusty harness on their nice new motor, not me. I would buy a harness like that whenever I need to do the motor in my car, I would almost certainly want the capability to tune the fuel delivery. I have been following wiht great interest some of the Fuel Injection threads, it is an issue that eventually will have to be addressed, to my mind

Random thoughts:

I would argue that one reason everyone wants to "go their own way" with PEFI is simply that there ISN'T an off-the-shelf solution available (except Jake's, at Jake's prices). I'm sure if there were an off-the-shelf solution available, it would be used in preference to a roll-your-own system by many people.

Most of the variations people want are just a matter of software.

I'm not 100% sure on this, but I believe the SDS system includes a harness made to order by the SDS people in their regular price. Mark Henry may know for certain.

DIS = crankfire (distributorless ignition system)

I am with you James, I see things the same way.

SDS does come with the harness, two actually, one for the injectors only and the other one for power and sensors. SDS is a favorite PEFI but their harness needs further refinement. Not to criticize SDS or any of the PEFI manufacturers, they are doing a great job of bringing powerful, generic PEFI systems to the market, but more is needed to make them just right for the 914.

The SDS injector harness requires yet a third supplementary harness (extra cost) with the resistors if you run the stock low-impedance injectors, its very crude looking, but I am sure it works well, SDS is a proven solution.

The SDS harnesses (or any generic PEFI harness for that matter) do not have exterior casing that is important to protect the wiring and be complete, and they do not offer D-jet plugs or rubber boots you have to graft on your own connectors, terminals and boots. They are also a single long harness piece which presents a mounting issue...how does one install the ECU outside of the engine bay and then install the harness with its big connectors at each end, to the engine? The harness has to go through the firewall. The length of their harness is fixed too, so you are limited to where the ECU can be installed, unless you special order it longer. You would have to disconnect all the FI harness attachments at the engine to do the engine drop without an easy means of disconnecting the harness from the ECU.

The SDS harnesses might be the beginnings of a good harness with modifications, but its not a complete 914 solution out of the box as I see it.

Emerald Performance is a PEFI that looks very promising. Jake is running dyno tests on it now as I understand, so I am anxious for the results. Their new K2 ECU (fuel only) is inexpensive and may be a great fit for simple D-Jet replacments to our 914s. Mack provides a generic harness with ECU connector which is just lengths of unterminated wires - he can supply connectors, but you need to custom fit the harness, cut all wires to length, install the connectors and case it if you want and can do it. Its a great beginning, but not a complete 914 solution out of the box.

My PEFI harness solves these issues and is a complete solution custom made just for the 914/4. And its made to accomodate all the PEFI systems and optional upgrades that are available.

Jeff,
Just wanted to chime in....I have a Perfect Power PRS-4 system, and it already comes with a wiring harness that plugs into the ECU, I just have to cut it to lenth, shrink wrap it and attach the required connectors (it sounds easy on paper) It appears to be nicely made and color coded. The bare harness was all included in the kit. I have yet to install it, but I plan on running the loose wires through a hole in the firewall and then mocking up the wires/connectors before cutting anything. Mine will be for a custom dual TB setup.

I take it that you are looking to fab a harness to work with stock components and be a plug and play solution. That would work if you sold an adapter for different PEFI systems.

Dominic, the trick is attaching things to the bare end of the harness. Good connectors are not easy to source. Connectors that work well with the OEM 914 components are even harder to source. Once you've found the connectors, you need yet more tools to attach them.

I've seen Jeff's work, and it's exemplary. I'm sure that long after the rest of the car has rusted away, one of Jeff's harnesses would still be there and operating perfectly. Getting that kind of quality requires high-dollar tools and parts, which is why Jeff would have to charge a premium price for it.

Jeff, your strategy sounds good to me. The bulkhead connector at the firewall will be the natural place to adapt to various PEFI units.

Thats exactly the plan. The ECU harness segment is built to the length you specify, and has a multi-pin connector (main disconnect) on one end in the engine bay and unterminated wires on the the other, which feed through the firewall. You then attach the ECU harness wires to fuses, resistors, the ECU connector etc. The main harness plugs into the multi-pin and onto each engine component and the relay board for power and fuel pump control.

My ECU harness and the plug/harness from the ECU mfr. makes the connection.

I hope my harness is not considered 'high-dollar'. At least half the cost is parts that everyone else will also need to buy anyway, but in fact as James points out, they also need to buy crimpers, heat guns and other special tools. And put a value on the learning curve. The value I am trying to offer is in the reasonable quality at a reasonable price harness and to save others the trouble of fabbing their own harness.

Thanks for the heads up on perfect power Dominic, I will check into them further.

Jeff I would be interested in your harness when I can determine what other parts to buy. everyone wants the best combo, but how do you detirmine whats best. I am experianced in cars that were built before all the electronics made them so complex. so I am at a loss to evaluate all these options. My motor is a 2270 and I would like to upgrade from carbs. also there are a lot of conversion options out there that your harness might be good for?

Bernie

I think that ignition control is an important part of an overall strategy. That does not mean that DIS is a requirement however. As soon as the distributor is eliminated for timing then you've got to drop the motor to mount the crank position sensor and magnets for a HALL-based system or a toothed wheel for VR. On top of that there is fabrication needed to mount the sensor and wheel. This is more than many are willing to do if they just want to replace their OEM system with a modern, programmable system.

A distributor still works quite well for distributing the high voltage for the spark plugs. For most applications a multiple coil setup is not justified. If the distributor is mechanically ok then the timing signal (Tach) should be fine. If the OEM distributor is worn out then just about anything that fits is viable. No vacuum needed, no mechanical advance. The dizzy used in the later Vanagons appears to be a good choice. These use a HALL sensor and are already locked.

The big hurdles in doing a PEFI retrofit are researching options, gathering parts, wiring, fabrication and programming. For someone looking to minimize the down time for replacement of the OEM system, eliminating the wiring, fabrication and programming would go a long way. It is true that each system would ideally be programmed (tuned) for each application. This was not the case for the OEM setup however. That is, except for very limited adustments, you don't have to tune it for each application. If you have the correct complement of parts it just works. For a close to stock engine there should to be a set of ECU parameters that will work as well as the original system. A WB O2 is not needed in every case. On the other hand, until someone does the work and makes it available everyone gets to program their chosen ECU.

I'll describe my situation because I think it is fairly typical. My engine is a recently rebuilt 2L. It is stock except for a Webcam #73 camshaft. It runs pretty good but the stock D-jet doesn't handle the cam real well at idle. I've got a good MPS and a spare. My harness is original and getting a little crunchy. I'd like to get my engine running well with the non-stock (but mild) cam and generally upgrade the wiring. ECU control of ignition is desirable as well. Megasquirt is attractive because of low cost and a large user base with an active newsgroup. As I look at various 914 installations, they are all different. I've had to pick and choose what I'm going to use for my installation. There is some satisfaction in doing this but if someone gave me a specific list of parts and a configuration I likely would have used it. I think having a specific configuration would suit many of us. The harness that Jeff proposes eliminates some of the messier aspects e.g., where to place relays. His proposal addresses the basic requirements and is still adaptable to specific needs. I want one!

QUOTE (Jeff Bowlsby @ Apr 8 2006, 01:52 PM)

I hope my harness is not considered 'high-dollar'. At least half the cost is parts that everyone else will also need to buy anyway.....

Jeff, I got more say on the subject, just too tired to write much right now...I can say price wise, your price is very, very fair...for the LINK FI, the "universal" wiring loom is $150 with no connectors...if you want a LINK engine harness they are $950 (price for a Type I installed in a bug)

of all the things related to doing an aftermarket FI, the wiring harness is a PITA....

Bernie, I think you should go with one of the following:

Haltech (many, many installs, plenty of support and online help) , LINK or get feedback from Jake on the Emerald system

Jeff,

On the subject of crankfire vrs dizzy, before I bought my LINK FI and was looking at which system to buy, a well known tuner of MoTec systems and the main importer of LINK both recommended running a dizzy instead.

Good luck Jeff. A good purpose built harness would be nice.

On the SDS it does come "custom" length on the FI part of the harness but the rest is generic. I don't know if the boots are necessary, as the SDS uses the better L-jet connector but it is a nice touch. For anything more custom than that SDS charges $30 plus to make it as you want, but that's pretty hard to do without installing a system before.

My biggest beef with the SDS is if you want to mount the ECU in the cab you have to drill a big 1-1/2 inch hole in the firewall for the big ass connectors. Also the crankfire has to be disconnected from the ECU...reverse from everything else. PITA

Unfortunately you will have to custom make a harness for each system and live with the fact that each guy picks a different system and there are no "standards" what so ever. Then the fact that many are cheap and will live with the generic harness.

I realize that SDS is selling to a large, mostly water-cooled market and I can live with the excess wire, as it is a real good system. But a harness that is plug and play would be bonus.

SDS will do the harnes for you and they do use the L-jet connectors as Mark has mentioned above. I have built several harnes using the L-jet connectors, luckly you can find these semi-new. But I will say it is a pain in the ARS!!!! Would I pay Jeff's price, no I am cheap.

But what I have done is I lay my harnesses out via string, the trick is getting a heavy enough string to make it bend like a wire. It then make each connection I need label all of them. Draw it out on a piece of paper, and send the entire thing to SDS. It has worked for me 3 times now. But then that customers car has had a Type-4 with D-jet conmnectors, a -4 with L-jet connectors, and now a -6 with L-jet connectors.

Another nice thing with SDS is they will give you a decent credit towards a system upgrade. I like that

Jeff good luck the price is fair, I know the cost of connectors, tools, etc..... Weather Pack GM stuff is not cheap either.

I am thinking of using them for my subbie swap. See my link below as to why I would.

A home made harness with crimp on connectors will be as bad OR WORSE than a worn out stock harness. It can cause countless small, intermittant issues. I think you've got a great thing going here, Jeff, and I'll be happy to support your harness on my engine builds that order the optional FI. Your price is spot on for the market your appealing to.