Sunday, January 22, 2017

Make America Flood Again

In my last post, I showed how I installed a Flex Fuel sensor on the Falcon. And while I try to show the details of how stuff gets done, I always still end up leaving out significant portions of the story. I guess that's just how it is. If stuff didn't get left out, it would be the same as just having everyone who reads this blog come over to my house and watch my every move. I don't want that. You don't want that. And most of all, Jen doesn't want that.

One thing I forgot in my last post was to show the mods I made to my Megasquirt relay board to accept an input from the Flex Fuel sensor signal. The relay board is handy, but I'm not sure if I'd use it again in the future. First off, it just doesn't feel as robust as I would like and second, it doesn't have enough input/output terminals on the board. The Megasquirt 2 ECU itself had enough I/O, but the relay board does not. After looking closely at the board, I decided that this was something I could remedy. 

First step was to remove the relay board. In theory it's simple, but so is patting your head with one hand and rubbing your belly with the other (in theory). I got into the driver's footwell in this awesome upside-down-feet-in-the-air position and removed all the wires and screws that held it in place. 

MS2 has a number of spare I/O ports called SPR 1, 2, 3, and 4. I wanted to use the "SPR 3" input for the Flex Fuel sensor. Here, hidden behind a relay, is the spot on the board where SPR1, 2, 3,  and 4 are terminated. They are not really accessible when the board is assembled.

I figured if I could get a wire from the board locations to a terminal block, I would be able to use all of the spare I/O. I found a terminal block on Amazon for a few bucks  and mounted it to the side of the relay board, and ran wires to it from the location behind the relay.

And just like that, I was able to get the Fex Fuel sensor input to the ECU.

On a side note, Jen and I found this neat KIA on our Sunday walk. It's been a bit rainy here in Long Beach.

Wednesday, January 18, 2017

The Smell of Drunken Hobos

Most people experiment with alcohol during their college years, and I was no exception. Where I differed was just how I experimented with it. While most of the rest of you were drinking low-level poison in quantities that would cause a cow to vomit out all four stomachs, I was burning it by the barrel. 

I lived across the street from a gas station that had one of the three E85 pumps in the state of Utah. For those not familiar with E85, it is a renewable fuel manufactured from the unfulfilled campaign promises of presidential primary candidates in the state of Iowa. The reason it is of interest to automotive enthusiasts is that it has an octane rating of approximately 105 and generally costs less than regular unleaded. When I lived across the street from an E85 pump, I ran my turbocharged Ford Ranger on E85 so that I could continually replace engines run more boost. 

In those days, if I wanted to run some mixture of gasoline and E85 instead of just one fuel, first I had to estimate the percentage of ethanol and percentage of gasoline. I had an excel spreadsheet for estimating the mixture, so after fueling, I'd pull out the laptop, estimate the mixture, and then connect to the engine control unit and change a fuel injector parameter. One time after changing that parameter, I was driving down the freeway and I received a call from my little brother, Marvin. He asked where I was, and when I told him, he let me know that he was about 3 miles behind me and could still smell the sweet scent of overly rich ethanol exhaust (which I actually kind of enjoy). As you can see, my methods weren't exactly sophisticated, but then again, neither was I. These days, I'm far more about 7% more sophisticated so I decided I needed a 7% more sophisticated solution for running ethanol mixtures. Enter Ford Taurus... wait, what?? 

As I've already shown, the Ford Taurus is an excellent car... ...for stealing parts from.  This time, I stole a flex fuel sensor from a Taurus. Flex fuel sensors have been fitted to a number of vehicles, mostly domestic US vehicles so that they could get a CAFE credit reduce emissions and save the world. With the sensor in hand, my first task was to mount it.

Junkyard treasures
Beginnings of flex fuel bracket

Mad decent aluminum welds

bracket installed
Once I had the bracket made and installed, I had to slightly rework the fuel system. Originally I had the fuel system setup as a deadhead style fuel system. I could try to explain it, but I won't. There's a drawing below, you lazy clod.

Legend says that a flow through fuel system is better than a deadhead system. Apparently the fuel doesn't soak up as much heat when it is able to flow through the rail. I think there are some other benefits as well, but honestly, I don't remember what they are,

With the sensor mounted, and lines run, I turned my attention to the seals on the sensor. There are two versions of this sensor, one for Ford and one for GM. The Ford version has threaded inlets and outlets, while the GM version uses barbed pipes as inlets and outlets. Using the Ford version allowed me to maintain consistency with my -6 AN fitting system I had used throughout my fuel system. The problem I ran into was that I was afraid the teflon washers I was using to seal the fittings would not hold. After a quick search on the McMaster-Carr website, I found just what I needed. I also learned that McMaster-Carr is only about 15 miles from me, so I went and picked them up rather than placing an order and hoping that they wouldn't charge me $90 to ship a pack of $3 washers.

teflon washers
bonded steel and rubber washer vs teflon washer
washer installed on fitting
detail of bonded washer

Next I had to wire the sensor to the ECU. It's a pretty straighforward affair, with a 12v switched, ground, and signal return wire. On this wiring harness, I've been rather anal about my wiring and connectors. I didn't want a mass of butt-spliced connectors in a nasty harness, and thankfully, the flex fuel sensor uses the same connector and terminals as the throttle position sensor. I had a few terminals left over, and was able to quickly make a harness for the flex fuel sensor.

My Megasquirt 2 ECU required a few mods in order to accept the signal from the sensor. These are outlined below, mostly just for my own reference, and for the benefit of any random google searchers who may come across the images.

The final step was to configure the software to accept the signal input. A couple clicks later, and I was reading a 1% ethanol mix. This seems reasonable to me, but I guess the only way to check is actually add ethanol to the tank and watch the sensor respond. Thankfully there are a handful of stations that sell corn squeezins within ten miles of me. 

There will be more pictures and words (you guys like those, right?) in the weeks to come. In the meantime enjoy this Volvo P1800 I saw the other day, and don't get eaten by tigers.

Monday, January 16, 2017

Return of the Blogger

Welcome back dear reader. It's been four months. I guess I took a 4 month sabbatical from blogging, but that doesn't mean I haven't been working. Like the bear who digs through your trash in the night, I have accomplished much while you slept. You are about to awake and find trash strewn across your yard several blog posts in rapid succession. But today I'm just going to show one of the diversions that have prevented blog posts. 

Some of you may know already, but my daily driver is a 1998 Jeep Cherokee I have affectionately coined "the TURD". And a turd it is, but I really like it. It recently had it's 190K mile birthday, and was in serious need of some suspension work. Over the Christmas break, I had several days off, and took 2 of those to tear into it.

I won't go into painful detail (and I can promise you that it is painful) but this job felt like a two day long street brawl. I'm just glad that things went as planned, otherwise it could have been a four or five day long street brawl.

The most useful tool for Jeep repair, just above the 700 lb-ft impact wrench and MAP torch
Old Crusties
New Shinies
Here we see the before and after. The difference is subtle, but nice. At some point I will have to replace the 7 year old tires on it. If tires could tell stories, these tires would have their own blog.

And finally, this is totally unrelated, but someone down the street from me has excellent taste in trucks. Stay tuned, more Falcon blog posts are coming soon.