S2E15: We put a lawnmower carburetor on our Saturn and then take it on the street.

in the previous episode we were faced with a huge problem when we discovered the fuel pump on our parts car was not working meh i'm surprised anything worked on that car considering it had been submerged underwater anyway just for giggles we bypassed the fuel injection system and installed a lawnmower carburetor and like most of you folks know this was very similar to the experiment thunderhead 289 did on its 302 cubic inch old school ford maverick well as it turns out the saturn engine ran extremely well with the carburetor and naturally we thought it would be a great idea to test the carburetor system on the slightly better car so today we're going to take what we learned on this car and transfer the carburetor system to this car now both cars are saturn s series and the only difference between them is the parts car has an automatic transmission while the good car has a 5-speed transmission once we complete the installation of the carburetor system on the good car we'll do some performance testing and of course check the fuel economy now as far as performance goes you don't have to be a rocket scientist to figure out that the already slow car will suffer a bit more when it comes to acceleration however the real question is will the fuel economy improve at all or will it get worse i reckon the first thing we need to do is to get some baseline data on our goods saturn so we can compare the completely stock fuel injection system to the hillbilly carburetor upgrade now we're going to cheat a little bit and inflate the tires to 40 psi because if we don't there'll be a bazillion comments on why we didn't do that now we did go over the car a little bit and fixed a few problems that were setting codes generally speaking the car is in average condition but the car is far from perfect our main concern was making sure the fuel injection system was working normally after all this car is 25 years old and has accumulated enough miles to more or less get it to the moon a couple of things to note here in kansas it's in the mid to upper 90s and of course this car doesn't have working air conditioning system but the heater does work fine i think today we will not be using the heater and just leave the windows down oh yeah and the radio doesn't work so pretty much there'll be a lot of suffering for the driver and i'll give you one guess who the driver was [Music] all right well let's see how fast this thing can accelerate with the factory fuel injection system [Music] so this is a good time to explain a few things we're using a scan gauge connected to the obd2 port to read the vehicle speed it appears that the scan gauge data updates about a second faster than the gps speedometer so out of all three speedometers we have the scan gauge is the one we trust so now we're going to check what kind of fuel economy the factory fuel injection system will deliver the idea is to fill the tank then do some driving and fill the tank again and see how much gas we burned now this car doesn't have a working fuel gauge and apparently when i pulled into the gas station i was running on fumes and i tell you what it was big bucks to fill the tank so [Music] [Music] do [Music] so somehow i managed to suffer through 115.3 miles in a car without air conditioning or radio keep in mind this time of the year in kansas the temperatures are in the upper 90s of course i just filled the tank and the fuel gauge says it's empty nice oh about 60 miles into the test we got a check engine light so let's check that out with the scan gauge [Music] looks like we got a po420 well that's interesting remember this car is not modified yet all right the obd2 diagnostic code 420 is being generated by this sensor so here's a quick explanation as the exhaust gases pass through the catalytic converter the raw unburnt hydrocarbons are annihilated by a reaction within the converter that's the theory in simple terms anyway this sensor is saying that there's still some unburnt hydrocarbons in the exhaust well 9 times out of 10 that means the converter is dying and needs to be replaced of course it could be a bad sensor and a lot of auto parts stores will try to sell you one but let's take a look at a few clues yep this car has 216 000 miles on it it's 25 years old and it's a saturn so it's likely been burning oil for the past 150 000 miles yeah i'm thinking the converter is past its prime the good news is the exhaust smells fine so the converter is still working it's just not working great so let's take a look at the baseline data for a completely stock and unmodified engine we were able to get the car to go from 0 to 60 miles per hour and 13.96 seconds now that's a bit slower than the advertised data that was published when the car was new but all things considered it's about right fuel economy well this is subject to debate we were able to squeeze out 42 miles per gallon out of this hoopty and well that's better than expected realistically this car should have delivered around 36 to 38 miles to the gallon now keep in mind i've owned many saturns and i've seen mpgs as high as 41 with all expressway driving and that's pretty much what we did on today's test i think we're close enough to keep moving forward so now that we have our baseline data we're going to modify the car by installing a lawnmower carburetor on the engine now in the previous video we worked out all the parts we'll need to convert the engine over to a carburetor well most of the parts this stuff here will allow the carburetor to fit the engine and give us a way to attach the accelerator pedal to the carburetor now all we need is a way to supply fuel to the carburetor for a field tank we're going to use a 6 gallon tank from a motor boat this tank allows us to accurately measure how much fuel is being consumed now the most accurate way to measure fuel consumption is by weighing the tank before and after the test so this tank will be perfect we're also going to need a way to pump the fuel from the tank to the carburetor and for that we'll use this low pressure universal fuel pump now even though this is a low pressure fuel pump it's way too powerful for this lawnmower carburetor we found out by testing that the carburetor can't tolerate any pressure the solution is simple we pump the fuel to the carburetor and to eliminate any pressure we provide a return path back to the fuel tank this system provides plenty of flow to keep the carburetor happy and we don't have to use a pressure regulator the fuel tank will also be modified to have a vent that will route to the outside of the vehicle so one of our concerns with the carburetor system is possibly damaging the catalytic converter and well as i previously mentioned the converter is on borrowed time anyway the converter on this car is fitted with two oxygen sensors the front sensor tells the ecu how to adjust the air fuel ratio and the rear sensor verifies that the converter is working properly now when we add the carburetor to the system we'll also swap out the narrowband oxygen sensor with a wideband sensor the wideband sensor will allow us to monitor the air fuel ratio and make the necessary adjustments in order to maintain a proper air fuel ratio of 14.65 to 1. that should keep the converter happy and help with the fuel economy the trick we're going to use in order to adjust the air fuel ratio from within the cabin of the car is to first adjust the carburetor so the engine's running rich then all we need to do is allow extra air to bleed into the system to lean out the mixture now thunderhead289 made a gizmo that he controls with a phone app to do this electronically but i think for our experiment we're just going to do it manually and just the air bleed system on the fly i reckon the first thing we'll need to make this system work is the wideband oxygen sensor now over at the jungle site you can get this wideband kit for about a hundy that's super cheap for a complete wideband system so i don't believe this is the best quality but for our experiment it should work fine let's see what you get for a hundred bucks well look at that it comes with instructions and for the most part the instructions are well written and makes complete sense and we'll get back to that in a minute this appears to be the harness that goes from the wide van sensor to the gauge i hate to say it but it feels like they use decent quality materials this little harness goes from the gauge to a 12 volt power source in the car it also has a 0 to 5 volt analog output to connect to an aftermarket efi system according to the instructions the output has four settings the default setting is 0 to 5 volt for a standard linear air fuel ratio it can also be set up for a lambda signal furthermore it can provide a 0 to 2 volt signal and maybe that's for a 3.3 volt ecu i'm really not sure the fourth and final setting is a 0 to 1 volt output and that's to mimic a narrow band signal theoretically you can install this wideband sensor and gauge in place of a standard narrowband sensor then route the narrowband signal back to the ecu this is interesting for the folks who care and make sense to them and for the folks who don't care it's just random words ah and here's the wideband sensor you know it looks and feels suspiciously like a bosch sensor but it doesn't appear to have any identification marks on it well at the very least it's a remarkable copy of a bosch sensor yeah this kit comes with a fancy gauge face upgrade meh i like the no frills default gauge face and finally here's the weldable bung that you can use to add to the exhaust system on your project car yep we ain't gonna use this instead we'll put this sensor in the hole currently occupied by the narrowband sensor so here's another look at the instructions looks like all we really need to do is to connect the power and ground the rest of this gizmos pre-wired for super easy installation so let's get back to work [Music] off camera i somehow managed to plug in a few connections to complete ninety percent of the installation i'm using this gauge pod that i got for five bucks on the jungle site the air fuel ratio gauge is a loose fit in the pod so i used the included rubber band to take up the slag for the power and ground connections well i used the plastic box that i had lying around and fit it with a terminal block and a power relay the relay gets a clean source of 12 volts directly from the battery and when the ignition key is turned on well that'll trigger the relay to turn on too of course i also put in an inline fuse to protect the car's electrical system so the black wire goes to ground the red wire goes to the relay and then that goes through a 12 volt power source the white wire well we ain't going to use that normally it connects to the aftermarket ecu or it can be routed back to the factory ecu if you change the settings to 0 to 1 volt output now according to the directions this blue wire doesn't connect to anything we have it connected to the terminal block just to keep it from floating around inside the case the last thing we need to connect is the wideband sensor so let's do that this is where the oxygen sensor is located on a saturn engine i really can't complain this is going to be an easy swap let me fast forward this for a minute so this is the factory narrowband sensor and as you can see the tip appears to be contaminated normally i would expect the tip to be a light tan color at any rate this sensor should be replaced if the car is going to be used on a regular basis but after we get done fooling around with this car it's getting a diesel engine so i really don't care if the sensor is on its last leg and this of course is the wideband sensor of unknown quality or brand but this is what was supplied in the kit so we'll use it finally we can connect the sensor to the gauge let's see if this thing works now keep in mind we disconnected the oxygen sensor to install this kit with the oxygen sensor disconnected the engine has no way to monitor the air fuel ratio and it's running slightly rich none of this matters because we'll be unplugging the fuel injectors and removing the throttle body the ecu will only be running the ignition system sure we'll get codes but that's completely expected next we'll remove the throttle body now in this car the throttle body doesn't do much it's basically just the throttle and it doesn't have injectors or anything nope it's just the throttle oh it does have this electronic thingy to adjust the idle speed and yeah we don't care about that on the carburetor we'll set the idle speed with a screw just like the caveman did back when the dinosaurs roamed the earth the inside of this intake manifold is coated with a thin layer of sludge and that's normal on a dry manifold system i reckon the fuel from the carburetor may dissolve some of this sludge so that's a bonus i guess yeah so just for the record we unplugged all the injectors and pulled the fuel pump relay there ain't no way this engine can run except with the lawnmower carburetor all right we're on the home stretch now before we can install the carburetor i have to relocate the throttle cable with this thingy now this may seem sketchy but the master cylinder is a great spot to anchor the throttle cable [Music] a bunch of zip ties will keep this badge in place well we ain't building airplanes and we'll be testing this car out in the corn fields so it'll be fine [Music] now we can install the carburetor this is so wrong but at the same time it's exciting [Music] so off camera we spent a few minutes adjusting the throttle cable so we can get maximum throttle opening i'm thinking we'll need as much throttle as we can get the fuel tank and fuel pump were mounted in the trunk and here we can see the fuel lines the system is primed and ready to go well let's start it up [Music] [Music] it took a bit of fiddling but we were able to dial in the carburetor good enough to do some road testing so what we did was adjust the carburetor to run rich and then we can control the air fuel mixture from inside the car by adjusting the air bleed valves it's going to take a few miles out on the road to fine tune the system but for now the car certainly runs well enough to inspire some confidence not a lot though let's take a look at how we add fuel to the car now keep in mind we're going out for a road test and not checking the fuel economy yet we'll probably need a few gallons of gas so we can avoid walking back to the shop [Music] all the quick connectors that we're using were meant for air or water and not rated for gasoline at some point we may need to obtain proper connectors the good news is there's virtually no pressure in the system so we don't expect any leaks the first hose that's being connected is the fuel tank vent line and this keeps the tank properly vented it's hard to tell from the video but it's nearly a hundred degrees fahrenheit when we film this having the tank vented is probably a good thing now these two lines are the supply and return lines easy connect easy disconnect but i don't recommend using these type of connectors i think it's time we do some road testing [Music] the car runs great but of course it lacks power and i'll say this it's very drivable on the back roads it's certainly a lot faster than our 420 cc honda insight we got it up to 65 miles per hour no problem it seems like it would go a little bit faster well much success the road test went fine and we're able to dial in the carburetor perfectly i think we're ready to do some real testing the fuel economy testing will be done by weighing the fuel tank before and after each test the difference in weight is of course the fuel that was consumed during the test i think this is probably the most accurate way to measure the fuel economy so in order to complete our formulas we need to figure out how much one liter of gasoline weighs yeah i know it's metric but all my measuring stuffs and metric don't worry i'll do the convergence for the imperial crowd and the metric crowd so first up is this plastic container how much does it weigh well it tips the scale at 65 grams whatever that means so with one liter of gasoline how much does it weigh now 775 grams total weight then we subtract the weight of the container and we get 710 grams per liter which is about what i expected an interesting thing about gasoline is it should be weighed at 60 degrees fahrenheit and our sample was weighed at 96 degrees well that's something to consider if we were going to experience huge temperature swings but during all our testing the temperature was consistently in the mid 90s so it all works out in the end like i mentioned earlier before and after each test the fuel tank is weighed and then we can calculate fuel consumption with extreme accuracy well do you recall how many times i mentioned how hot it was here in kansas yeah well there's something we didn't figure on so after about 12 to 15 miles of driving the carburetor would vapor lock every single time we took the car out for a test so when the vapor lock occurs the engine would pretty much run out of gas [Music] the only thing we found that worked is to shoot a bit of water on the carburetor now if we didn't cool down the carburetor it took 15 to 20 minutes on the side of the road with the hood open before the carburetor would start working again now standing by the side of the road ain't fun especially out in the middle of bfe a few times i was offered help by concerned citizens and that's cool so i was never really stranded per se but pulling over to cool down the carburetor put a huge damper on things so we took the car back to the shop and started taking things out of the engine bay that was restricting air flow under the hood before long we had a nice pile of useless parts if you notice the cooling fans in a pile of useless parts well that's because it was fubar technically you don't need a cooling fan out in bfe as long as the car is moving the engine will stay cool so we opened up a lot of space and most likely we improved something i guess anyway the biggest improvement came when my buddy eric stopped by and said why don't you reroute the windshield washer to spray on the carburetor and well that's what we did check it out now that's what i'm talking about finally we had a solution well it worked great and we're getting past the 20 mile mark but we still had to pull over to refill the washer fluid reservoir so back to square one so i really didn't want to cut a hole in the hood on this car but we're out of options sort of you see the hood from the parts car is completely different but the hinges line up and it will latch to the gizmo on the coop so we ended up sacrificing the parts car hood in order to continue with the experiments [Music] so yeah buddy now we're talking this is pretty much our last option we did a little more trimming on the inside of the hood to make a clear path to the carburetor and this will be the game changer well with the combination of the hillbilly hood scoop and the windshield washer carburetor cooler we managed to go 55 uninterrupted miles in this hoopty with a lawnmower carburetor so at this point we gathered enough data for fuel economy and the only thing left to do is find out how fast this car can accelerate of course for maximum performance we recommend cooling the carburetor before attempting high speed runs [Music] so we have data so fuel economy is up first and we have a ton of data initially we were unsuccessful in getting the car to go further than 30 miles without being stranded on the side of the road for hours so there was a lot of short tests and we'll call them less than 30 mile tests for these tests we managed 38 miles per gallon and the interesting thing is all the short tests yielded exactly 38 miles per gallon so that was very consistent next we managed to get the car to go 45 miles with some minor interruptions on the 45 mile test we got 39 miles to the gallon and finally we went all out and pushed the car to its limits on a 55-mile trip and that got us 41 miles per gallon i can see a trend and it looks like the carburetor ain't any better than the efi on this car now keep in mind we put down over 300 miles testing fuel consumption with this carburetor lots of tweaks a lot of modifications but in the end we just don't see an improvement now as far as drivability the car is rock solid for 12 miles then once everything heats up oh brother it may be that the carburetor we're using is too big and perhaps something like a moped carburetor might offer better atomization now i'm not being snarky i'm being serious the problem is on this car whatever we use will likely suffer from vapor lock this time of the year so i'm not motivated to take this experiment to the next level anyway the fuel economy was a bit of a disappointment let's check out our acceleration times and see if there's an improvement there the unmodified fuel-injected engine got the car up to 60 miles per hour in a lazy 13.96 seconds and yeah that seems kind of slow with the lawnmower carburetor things get a lot worse now we're looking at 34.82 seconds to get to 60 miles per hour to be fair at wide open throttle the air fuel mixture tends to lean out a bit and we do lose some power i think in a perfect case we could knock off two to three seconds but that's still pretty slow so during all our testing we closely monitored the data coming from the obd2 port our biggest concern was whether or not the ecu would provide ignition advance with so much chaos going on i mean the ecu was literally blind and didn't have access to the o2 sensor and the throttle position sensor was electrically connected but it wasn't actually connected to the lawnmower carburetor throttle well apparently on this engine it didn't care the ignition system functioned normally and we could see that the ecu was calculating ignition advance so what sort of codes did we get let's check them out well the first code was for an inactive throttle position sensor and that makes sense the second code was for no activity on the o2 sensor circuit well okay apparently you can't fool this ecu the third code was related to the engine idle speed being lower than expected meh the fourth code was for the idle speed being higher than expected yeah i could see that happening and now we have two more pending codes well it looks like another o2 sensor code and no big deal and the last one is for the map sensor circuit hmm that's interesting now that's an unexpected code i'm just going to guess and i could be wrong but since we were literally spraying gasoline inside the intake manifold we may have dissolved enough crud to plug up the orifice for the map sensor or it's something else on saturn's it's common for the map sensor to get boogered up from all the sludge perhaps that's what it was i'll have to check it out to be sure i guess it's interesting to see that we didn't generate another po420 code so i guess we got something right now in the previous video the viewers overwhelmingly voted to see the kabuto d722 three-cylinder diesel swap and we're pretty excited to be doing that swap the parts are being fabricated off-camera and we'll bring you that episode in the near future in the meantime we can still do some experiments on this car now in the comment section of the previous video someone suggested that we try cylinder deactivation well i had a look at some key components and made up some prototype parts and it is possible now it wouldn't be an active deactivation system no that would be too complex for youtube video but it would be a simple deactivation system and we would be using the stock fuel injection system with some minor modifications i think it'll be fun so if you want to see a three cylinder diesel saturn roll coal and watch us torture this current engine a little bit more be sure to subscribe and if you made it this far you must have liked the video if you would please click on the like button that keeps us going in the right direction oh and if you have any experiments you'd like to see on this car feel free to put them in the comment section until next time

Channel: Robot Cantina

Views: 236,755

Keywords: $99, 212 cc, 420 cc, 420 hemi, alternative transportation, custom, cvt transmission, diy, documentary, efi, electric car, electric vehicle, engine mods, engine swap, fabricate, fuel economy, fun, funny, go cart, megasquirt, gocart, gokart, NO2C, goonzquad, great idea, gx390, hack, hand made, harbor freight, hemi, hho, high performance, home made, homemade, hp, hybrid, lada, lawn mower, lawnmower, modification, modify, motor, motor swap, motorcycle, mpg, predator powered car, Fuel injection, speeduino

Id: PBs48Qi5NeM

Length: 28min 22sec (1702 seconds)

Published: Sun Jul 03 2022