Other Buicks and Years > Other Buicks
Installing a XFI Sportsman Throttle Body EFI System in a 1965 Buick.
elagache:
Dear fans of “assertive” 1965 Buicks,
My trusty 1965 Buick Special is finally running again after a long struggle to fit her with a big-block Buick engine, a 200-4R transmission, and bunch of other changes. When I first ordered the engine in 2011, I was persuaded to switch from a carburetor to the EZ-EFI 1.0 electronic fuel injection system built by FAST (Fuel Air Spark Technology). Given the car’s history, it didn’t take a lot of persuading.
As it turns out, my wagon has been relatively unlucky with both carburetors and now electronic fuel injection systems. I don’t know well the car performed when I as a kid, but there was enough of a cold starting problem that my Dad opted to back-fit a manual choke (more on that later.)
In addition, my Dad and I undertook the risky project of rebuilding the Carter AFB carburetor sometime around 1975 or so, certainly before 1978. I don’t why Dad thought this was necessary, but he clearly thought it was. What made this project risky was that we only had one car at the time, so if something when wrong with the rebuild we were stranded. Here is a snippet from the rebuild instructions. I still have the sheet after all these years:
Note the date in the top left corner!
Somehow we got the carburetor back together at the end of the weekend and "Biquette" (that’s the family name for the car) was back in service. I started to drive in the late 70s and soon came to really hate that manual choke. Often I was sent to pick up my Dad from the train station after work and I would frequently forget to release the choke during the short drive. As a result, when I tried to stop the engine - the dieseling was most unpleasant!
In 1979 we had Biquette’s engine rebuilt a first time and I pleaded for an automatic choke. During the rebuild, Biquette was fitted with a 1968 Chevy carburetor (with a working automatic choke) which it was hoped would improve her fuel economy. Alas, Dad never did learn which model of carburetor or which Chevy cars had them. You can see were that would lead.
That unknown Chevy carburetor was a dependable performer. It ran from 1979 until well past 2000. Somewhere along the way, I found at (J.C. Whitney of all places) an electronic ignition conversion kit that put an end to replacing the points every 3 month.
Alas, finally that Chevy carburetor gave up the ghost and nobody was able to identify which model it was. Actually the real problem was that the repair shop I was going to was losing interest in older cars, but I didn’t realize that at the time.
Since I knew Biquette had been originally fitted with a Carter AFB, I managed to get my hands on one of those rebuilt. Alas it only lasted about 2 years before the rebuild - broke. I sent it back to be rebuilt yet again, but the my repair shop just couldn’t install it correctly - nobody knew how to work on Biquette anyone.
At this point I was desperate and eventually found a new repair shop: Orinda Motors. It turned out there was a lot of neglected maintenance to catch up on and as part of this Biquette was fitted with an Edelbrock Performer carburetor. At least this carburetor worked, but it didn’t work particularly well. It was necessary to leave the idle unusually high to keep the engine stable.
So what this long story shows is that - carburetors and I have never exactly gotten along. So I leapt at the chance to switch to electronic fuel injection.
Fast forward to today and introduce a new and unexpected problem. The EZ-EFI 1.0 system has a known annoyance: it periodically “hunts” for the lowest stable idle. It does this even after it has supposedly completed its self-tuning procedure.
For most muscle cars this is only an annoyance. The idle is a bit rough, but the computers never allow the engine to stall completely. As soon as you step on the gas, the computer shifts into another mode of operation and the hunting problem goes away.
The fly in the ointment for my wagon is that I’m trying to keep the engine at as low an operating RPM as is practical to get better fuel economy. Most muscle cars run with a comparatively short rear end, so the car won’t move without stepping on the accelerator pedal. My wagon has a 2.78:1 rear end ratio which effectively allows her to operate more like a modern car. On a surface road at 35 mph, the 200-4R transmission shifts into overdrive, and she coasts at idle. In addition, such a tall rear-end means that the car will maneuver with the engine at idle.
It is these situations were the EZ-EFI 1.0 “hunting” at idle is no longer a minor annoyance. Instead of being easy to control, the car can lurch unexpectedly because the fuel injection system will cause the idle to drop below what is stable and then give a shot of fuel to allow the engine to recover. If you are trying to enter the garage, such lurching is most unwelcome!
Okay, given that this seems to be a software/firmware sort of problem, my first thought was to see if there was an upgrade for the EZ-EFI 1.0 system. The only known update goes back to 2010 - before this model was purchased! So there was no remedy available for the existing system.
The guys at Orinda Motors struggled with the problem a bit and eventually learned of a fellow by the name of Richard Nedbal who is based the Sierra foothills of California and is a specialist on FAST products. Here is the website of his outfit:
http://www.fastmanefi.com/
Rich explained that the EZ-EFI 1.0 system is little more than a legacy product and FAST is now concentrating on their EZ-EFI 2.0 systems and later products. He recommended the XFI Sportsman Throttle Body EFI model. It has a similar installation footprint to the system already installed so the upgrade won’t be as painful. This system is a hybrid in terms of tuning. Unlike many systems, it does not require the car to be transported to a chassis dynamometer and tuned manually by a specialist. However, it does allow you to modify the tune using a laptop and special software. So unlike the EZ-EFI 1.0 system, if there is something unpleasant about the tuning of this system, there is a way to correct it.
In addition, Rich recommended having the fuel injection system also take over control of the ignition. To do this he recommended the E6/E92 Ignition system kit. These components will then be hooked up to a “dumbed down” MSD distributor that will simply serve to distribute the spark to the individual cylinders.
This is a radical upgrade but it is really what I was desiring all along. My goal was to modernize Biquette so that she could perform comparatively well with our modern cars. The EZ-EFI 1.0 system was not a modern system, but basically a “smart” carburetor and, as it turns out, it isn’t very smart. This new system will take advantage of the modern developments in fuel injection and control so that the engine will perform better on less fuel.
I placed the order for the FAST components and MSD distributor last week. Alas, FAST is waiting for a shipment of air temperature sensors and won’t be able to ship their parts until this Friday. Realistically, installation won’t start until the beginning of March. Still I thought you guys might be interested in this more radical makeover of a 1965 Buick. I’ll report on this thread on the progress as the work unfolds.
Cheers, Edouard :occasion14:
cwmcobra:
By all means, keep us posted Edouard. Sounds like an interesting project that many could learn from.
Chuck
GS66:
I have thoughts of this every so often too. Will be following along!
elagache:
Dear Chuck, Jim, and fans of high-tech mid-60s Buicks,
Thanks guys! I'll definitely keep you posted on how this project unfolds. It isn't the sort of thing that will work if you are seeking 100% originality of course. However, with a little clever hiding of components, I think you could have this sort of modern functionality in an engine bay that looks very close to what rolled off the assembly line in 1965.
By the way I got a chance to test another one of those modern conveniences yesterday. We literally had a February heat-wave and yesterday when I had my wagon out for some exercise the car got hot enough that I needed to run the air conditioner! The Vintage Air system did work great, but I sure would appreciate if the earth's climate would remember this is - after all - winter!
Cheers, Edouard :occasion14:
Cheers, Edouard
WkillGS:
--- Quote from: elagache on February 16, 2016, 06:06:09 PM ---Dear fans of “assertive” 1965 Buicks,
.... The EZ-EFI 1.0 system
.... The idle is a bit rough...
.... Most muscle cars run with a comparatively short rear end, so the car won’t move without stepping on the accelerator pedal. My wagon has a 2.78:1 rear end ratio....
...... the car can lurch unexpectedly because the fuel injection system will cause the idle to drop below what is stable and then give a shot of fuel to allow the engine to recover.
--- End quote ---
It's not the difference in rear axle ratio, that's insignificant.
The stall speed of the converter is too low. A higher stall converter will slip more under those conditions (high idle) and the car will not creep or lurch (with brakes applied).
The 65 and 66 Buicks had a nice feature in the ST300 transmissions.... the 'switch pitch' converter.
I have a lumpy cam in my blue car (old Isky grind). With car stopped and converter in the 'low stall' position, it will pulsate when stopped.... the rumpity-rump of the engine transfers some power to the rear wheels (thru the 4.11 rear) and it does pull against the brakes in a pulsating way.
But with the converter in 'high stall' it slips enough so the engine can do it's rumpity-rump thing without the power getting to the rear wheels. It's perfectly content sitting at a stop light, smooth as can be.
Once under way, the converter switches back to low stall for more efficient operation.
Perhaps your "Biquette" would be much happier with a good ole Nailhead and st400!
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