Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - 1997 VW Golf

dfeldt91 · 12-06-2015, 02:32 AM

December 1st, 2015 - With Thanksgiving out of the way I was able to finally jump into this ecomodding project. The biggest concern with any new ecomodding project should be getting the car running and driving well, so I decided to start by replacing the clutch. I had no clue what I was doing so it took me three days while drinking and eating lot of Panda Express with a friend. I ended up bending the dust covers for the transmission so I bought new old ones at the junk yard. The car drove the 120 mile round trip to the friends house just barely. 75% through my trip it was raining hard enough for me to have to pull over which incidentally happened right after I ran over a branch causing something to fail leaving me with a dead engine at the top of the off ramp. Got it started after cranking for minutes and it was smoking BAD. I thought I blew a head gasket. Let it sit for an hour while I stood in the rain trying to figure out the issue. No one stopped of course... It would die whenever the engine got down to below 1200 RPMs or so and was in gear so I literally had to rev the engine then slam it into gear and I was off until I would come to a stop and the car would die for a few minutes, got stuck in the middle of two intersections on the way home, LAME. Anyhow, the next day I cleaned the white gunk from the PVC valve plastic thingamajiggy that always gets clogged with these engines and it stopped dying when below 1200 RPM. The starting issue persisted however and each morning I have to crank it for 30 seconds to get it to start. Pretty sure it is the Hall Sensor or the Crankshaft Position Sensor as both are used when in open loop below 1300 RPMs or so which makes sense since the car would die when below that and in gear. My guess is the stick I hit snagged the wire of one of the sensors since the wires hung low.

December 5th, 2015 - Today I purchased some cheap coilover springs for $53 shipped. They replace the springs on the stock shocks. I plan to lower the car just an inch or so to get rid of the gap between fender and tire which should improve MPG and look better.

December 7th, 2015 - I went to the junk yard and picked up a used MAF sensor, rotor cap, main plug wire and coil. I'm going to replace all these and hope the starting issue is from one of them. I cleaned the new MAF and installed it which did not fix the problem. Haven't installed the other stuff yet. While at the junk yard I was able to pick up a set of after market "tuner" style wheels that were in good shape with tires for $140. Stock lug bolts did not fit so I ordered some narrower lug bolts. On a drive to go fishing I stopped at a rest area to disable my daylight running lights permanently. If you have an MK3 you can do so by pulling the headlight switch and cutting the number 15 wire. They are labeled on the connector and it is the corner yellow wire, super easy to spot. I also fixed my crankcase breather tube that was snapped by cutting it off at the break and sticking it into the connecting tube, easy fix.

December 10th, 2015 - I bought a sheet of corrugated plastic to use for the belly pan and the rear wheel well cover. When the rain stops long enough I will get out and start cutting and attaching.

December 12th, 2015 - I got a bluetooth engine scanner in the mail an hour ago and went for a drive to check out the instant and trip miles per gallon through the device on my phone. It is really cool seeing what the best approach to a hill would be(certain gear, rpm, etc) to make it using the least fuel possible. I also used the device to find out that my engine shuts off when the accelerator pedal is not pressed in and it is coasting. I would watch my MPG go from 40 or whatever all the way to 255 which I suspect to be the maximum with this device. I think this alone will give me at least a 15 to 20 percent increase in fuel economy because I found out that coasting in neutral was wasting gas as compared to coasting in gear which uses zero. Also, I can now fine tune my pedal pressure and gear selection for best MPG. The only thing I don't like about the MPG calculations through this device is that it sees that the engine is still "on" if I turn off the engine at a long light so the average MPG goes down as it sees the engine getting zero MPG. I'm excited to get the rest done now and see if I can hit 45 mpg average.

December 14th, 2015 - I got some free time today, actually I just didn't feel like working and I work from home on my time so.....I went out and cut some coroplast covers for the open sections where my fake fog lights were missing on the bumpers. That covers two sections that measure about 3" by 7" that were open to the engine bay. I also got the new narrow lug bolts for my larger wheels/tires. Got them installed. Went from 195/60/14's --> 195/60/15's. Got pocket raped at Les Schwab: $65 to dismount, clean the bead and seal 3 tires. Had to be done though because the stock tires were causing me to slide around when wet and were unsafe. New tires give me quicker acceleration. I don't feel like I'm revving too high before shifting now. Initial thoughts: Decel mode is not engaged at certain times it normally would be so instead of burning no fuel I am burning about 60mpg so I have to downshift to remedy that which causes the car to slow quicker. Only thing to do would be to get my engine off coasting switch wired in. Still need to get a wire with inline fuse to do it safely and not ruin my ECM should it become overloaded since I have to bypass the original fuse to break the electricity going to the injectors.

January 12th, 2016
I have been away for a while as I have started school and my schedule is changing quite a bit. I'll do a better job of keeping up with this thread now that I am getting th hang of school and am restructuring my time.

12-06-2015, 02:32 AM	#3 (permalink)
dfeldt91 EcoModding Apprentice Join Date: Mar 2015 Location: Salem, Oregon Posts: 128 Mazda 3 - '06 Mazda 3 iTouring Thanks: 7 Thanked 20 Times in 17 Posts	December 1st, 2015 - With Thanksgiving out of the way I was able to finally jump into this ecomodding project. The biggest concern with any new ecomodding project should be getting the car running and driving well, so I decided to start by replacing the clutch. I had no clue what I was doing so it took me three days while drinking and eating lot of Panda Express with a friend. I ended up bending the dust covers for the transmission so I bought new old ones at the junk yard. The car drove the 120 mile round trip to the friends house just barely. 75% through my trip it was raining hard enough for me to have to pull over which incidentally happened right after I ran over a branch causing something to fail leaving me with a dead engine at the top of the off ramp. Got it started after cranking for minutes and it was smoking BAD. I thought I blew a head gasket. Let it sit for an hour while I stood in the rain trying to figure out the issue. No one stopped of course... It would die whenever the engine got down to below 1200 RPMs or so and was in gear so I literally had to rev the engine then slam it into gear and I was off until I would come to a stop and the car would die for a few minutes, got stuck in the middle of two intersections on the way home, LAME. Anyhow, the next day I cleaned the white gunk from the PVC valve plastic thingamajiggy that always gets clogged with these engines and it stopped dying when below 1200 RPM. The starting issue persisted however and each morning I have to crank it for 30 seconds to get it to start. Pretty sure it is the Hall Sensor or the Crankshaft Position Sensor as both are used when in open loop below 1300 RPMs or so which makes sense since the car would die when below that and in gear. My guess is the stick I hit snagged the wire of one of the sensors since the wires hung low. December 5th, 2015 - Today I purchased some cheap coilover springs for $53 shipped. They replace the springs on the stock shocks. I plan to lower the car just an inch or so to get rid of the gap between fender and tire which should improve MPG and look better. December 7th, 2015 - I went to the junk yard and picked up a used MAF sensor, rotor cap, main plug wire and coil. I'm going to replace all these and hope the starting issue is from one of them. I cleaned the new MAF and installed it which did not fix the problem. Haven't installed the other stuff yet. While at the junk yard I was able to pick up a set of after market "tuner" style wheels that were in good shape with tires for $140. Stock lug bolts did not fit so I ordered some narrower lug bolts. On a drive to go fishing I stopped at a rest area to disable my daylight running lights permanently. If you have an MK3 you can do so by pulling the headlight switch and cutting the number 15 wire. They are labeled on the connector and it is the corner yellow wire, super easy to spot. I also fixed my crankcase breather tube that was snapped by cutting it off at the break and sticking it into the connecting tube, easy fix. December 10th, 2015 - I bought a sheet of corrugated plastic to use for the belly pan and the rear wheel well cover. When the rain stops long enough I will get out and start cutting and attaching. December 12th, 2015 - I got a bluetooth engine scanner in the mail an hour ago and went for a drive to check out the instant and trip miles per gallon through the device on my phone. It is really cool seeing what the best approach to a hill would be(certain gear, rpm, etc) to make it using the least fuel possible. I also used the device to find out that my engine shuts off when the accelerator pedal is not pressed in and it is coasting. I would watch my MPG go from 40 or whatever all the way to 255 which I suspect to be the maximum with this device. I think this alone will give me at least a 15 to 20 percent increase in fuel economy because I found out that coasting in neutral was wasting gas as compared to coasting in gear which uses zero. Also, I can now fine tune my pedal pressure and gear selection for best MPG. The only thing I don't like about the MPG calculations through this device is that it sees that the engine is still "on" if I turn off the engine at a long light so the average MPG goes down as it sees the engine getting zero MPG. I'm excited to get the rest done now and see if I can hit 45 mpg average. December 14th, 2015 - I got some free time today, actually I just didn't feel like working and I work from home on my time so.....I went out and cut some coroplast covers for the open sections where my fake fog lights were missing on the bumpers. That covers two sections that measure about 3" by 7" that were open to the engine bay. I also got the new narrow lug bolts for my larger wheels/tires. Got them installed. Went from 195/60/14's --> 195/60/15's. Got pocket raped at Les Schwab: $65 to dismount, clean the bead and seal 3 tires. Had to be done though because the stock tires were causing me to slide around when wet and were unsafe. New tires give me quicker acceleration. I don't feel like I'm revving too high before shifting now. Initial thoughts: Decel mode is not engaged at certain times it normally would be so instead of burning no fuel I am burning about 60mpg so I have to downshift to remedy that which causes the car to slow quicker. Only thing to do would be to get my engine off coasting switch wired in. Still need to get a wire with inline fuse to do it safely and not ruin my ECM should it become overloaded since I have to bypass the original fuse to break the electricity going to the injectors. January 12th, 2016 I have been away for a while as I have started school and my schedule is changing quite a bit. I'll do a better job of keeping up with this thread now that I am getting th hang of school and am restructuring my time. Last edited by dfeldt91; 01-12-2016 at 10:24 PM..