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| [GMCnet] FiTech EFI looks like the real deal [message #292250] |
Tue, 15 December 2015 19:46  |
glwgmc
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FiTech EFI First Impressions
Jerry Work
December 2015
How could you not like a GMC that drives like a modern car? At this point I couldn’t be happier with the ease of the installation of this FiTech EFI system or the strongly positive impact on how the Clasco now drives. And, this after just a few miles of the EFI self learning. I understand from the factory designers that the improvements will continue over time as the system experiences more and more varied driving conditions. The software controlling the learning appears to be quite sophisticated as if you are one who wants to twiddle (not me) there is a document on the FiTech web site that describes the literally dozens of parameters you can set targets for, or modify if you want to, which will influence the learning process and the eventual running parameters. I don’t even understand what most of them would do right now. The good news is you don’t need to even go to that part of the hand held controller’s menu. The system literally will learn as you drive with no input from you other than inputting a few simple engine related questions such as displacement, the type of cam, target idle speed, etc. It remembers the most current settings it has learned and each time you start up begins from there but continues to learn, gradually reaching the point that no further minor tweaks are necessary for the kinds of driving experiences you have actually encountered. If you do encounter something new, it will learn from that new experience and constantly add to its knowledge base.
When I first fired the system it had trouble starting on its own. Once it did it settled in quickly. I fiddled with the factory set idle air controls to open the throttle valves a bit more to let in more air at cold start and that did appear to help but effected high idle when cold as you would expect. When I called the techs (who have answered the phones immediately each time and seem to be quite knowledgable) the first question was “do you have 12vdc while cranking?” I had used the choke wire from the electric choke on the old carb and had tested it for 12vdc with the key on, but never tested it during cranking. Turns out the source I used (the heater blower low speed yellow wire) was one that was dead while cranking and the FiTech unit turned off while the starter was cranking. So, it was only supplying fuel before start and after it finally got rich enough to start and I relaxed the key from the start to the run position. Self inflicted wound. As soon as I pulled voltage from a source that was hot both at key on and at crank, the system fired as soon as the key turned whether hot or cold. More on this point later.
Once I had that sorted out I then fiddled with the idle air control to try to get it back close to the factory setting. I am close, but not yet quite where I want to be. The techs walked me through the process right on the phone. Once I got that close I asked if there was anything else I needed to do. He chuckled and said something like, “just drive it and have fun, that is what all of us here do and we have our own units installed on a wide variety of our own old cars and trucks. No one said we have to, it is just that we are all gear heads and love what the system does for drivability of our older vehicles.” That is when I did my first test drive.
The results are most impressive. It looks to me like the initial settings error on the side of running too rich and then lean out as the learning progresses. Once the weather clears and after we get back from Christmas in Vancouver, BC, I look forward to tackling some of the steep grades around here. From what I can feel now I don’t expect anything but more grins when I do. The most immediate impressions are that the 455 now starts instantly hot or cold, runs much more smoothly at all RPMs hot or cold and has immediate throttle response hot or cold. I also think it runs at a bit higher vacuum and may have a bit more oomph but that is just anecdotal at this point. We plan on taking the Clasco south for the winter so by spring I should have around 5000 miles of experience with the system, and by the time of the October four club Coos Bay, OR, rally should have something around 10,000 miles on the clock. I plan to do a detailed presentation on installation tips and what I have learned about driving performance and efficiency at that rally.
That October rally is being jointly planned and put on by all four of the west coast GMC clubs - GMC Cascaders, GMC 49ers, GMC Pacific Cruisers and GMC Western States. It should be a large and bang up event. Gary and Rebecca Bovee are the rally masters and I’m sure will be providing more event details as they get set in place. It should be even larger and better than the three club rally we did there a couple of years ago. So, put a mark on your calendars and make a date with the magnificent Oregon coast next fall.
Back to the issue about where to draw system key-on power. The logical place appears to be from the battery + terminal on the bottom of the HEI distributor cap. That wire is hot both with the key on and while cranking. But, it is only an 18 gage wire so can’t carry much in the way of amperage. It is also traverses a round about path to get there. A 12 gage wire from the battery runs to the ignition switch at the bottom of the steering column and from there to a connector. From that connector it is only 18 gage to the distributor. I can read a measurable voltage drop from battery voltage to that connector on the Clasco during key on so it has to have high resistance somewhere. I also read quite a voltage sag while the starter is cranking. I am going to probe more tomorrow but likely will run a 12 gage wire from the ACCY terminal in the fuse box (which appears to be hot during start and run) out to that battery + post on the distributor to provide more and more stable voltage to the HEI distributor and the FiTech EFI during start and at run. I will let you know if that appears to make any difference. The system appears to perform just fine as it is so that key on voltage drop from battery voltage and the sag during crank may not matter much to either the HEI or the EFI.
I have no way of knowing whether all of the EFI units on the market - the self learning variety or the build or buy the tables yourself variety - would do as well or maybe even better than this FiTech system, but I continue to be impressed with the combination of apparent build quality, ease of mechanical and electrical installation, the cleanliness of the installation (lack of wires running all over the place as the only external sensors are the O2 and water temp), the helpfulness and responsiveness of the FiTech staff, the value proposition at their $1000 price point, and how very much better the driving experience is. I only have direct experience with this one system so maybe all of the EFI offerings offer a similar experience. Time will tell. Certainly it would be nice if I wind up with more apparent power or better fuel economy, but I would buy this system again just for the difference it made in the driving experience. And, for my style of driving and my expectations I don’t care if I could ring out a fraction more here or there by different spark control or some other means, what this system does on first impression is enough for me. If it proves to be as reliable as I think it will be, I will be a happy camper and looking to do the same thing to the Royale.
My guess is that by this time next year all the after market EFI systems will be at the same $1000 price point as this FiTech unit (or will be driven out of the market) and all the different makers will offer a front mounted, integrated fuel management/surge tank and submerged HP pump system as the one now offered by FiTech. And, it couldn’t come at a better time for our old GMCs as far as I am concerned.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
glwork@mac.com
http://jerrywork.com
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Jerry & Sharon Work
78 Royale
Kerby, OR
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