View Single Post
  #576  
Old June 20th 2018, 14:24
owdlvr's Avatar
owdlvr owdlvr is offline
Administrator
 
Join Date: Sep 2008
Location: Canada - West Coast
Posts: 851
I suppose I should update the Rally Bug thread…

On our Spring Thaw event in April, the Rally Bug was essentially flawless. It’s running quite rich, and I thought I’d have time to play with the tuning before / during the event, but truthfully didn’t. The organizer spends too much time stressing over the actual event, so there just wasn’t time to breathe and play with the tuning. Despite an excessive fuel bill, the car ran flawlessly throughout the event. Hosted 89 cars, 181 people for dinner each night. As the event progressed, I noticed it was harder to start first-thing in the morning, but didn’t think too much about it, as it’s an issue that seems to have crept up since switching to fuel injection.









Following the Spring Thaw, it was home for a very fast turnaround before loading the car onto the trailer for Colorado. I made some adjustments to the brake bias, changed up the tools and spares package, and headed onto a long road trip south. This would be the real test of the fuel injection system. Could I go from Sea Level to 6,000ft (and 11,000ft on mountain passes) without problems?

After 5 days of driving and being a tourist, I finally arrived at the unloading spot for my trailer. Fired the bug up, with significant difficulty, and took it for a spin. Whoa was it terrible! Since switching over to fuel injection, it’s never run well if cold…but this was something else. I wiped the map, started with a completely fresh map, and started retuning the car from the very beginning. I spent a full day working on the map, and when it was finished the car ran quite well. So well, in fact, that I would argue it was becoming fuel-efficient! Amazing what will happen if you spend some time tuning, instead of trying to do 2min sessions every once and a while :P



The first two days of the Colorado adventure were flawless. We started in Grand Junction, went over the Grand Mesa and then into Gateway Canyon, where we turned south to Telluride. Highway 141 through Gateway is one of my favourite roads of all time…you might know it from The Grand Tour Jaguar Episode (hint, when they leave the resort stealing all the toiletries, that’s Gateway Canyon Resort). https://www.youtube.com/watch?v=RlPhIy7Te18





From Telluride we went up and looped through Moab Utah, before heading back into Grand Junction for the night. Day two continued to be flawless, so much so that Ross, Jacob, Erik and I decided we’d take the Fiat and Rally Bug on an off-road adventure. We went over a mountain pass, about sixty miles, on a gravel excursion that definitely wasn’t in the official route book!


As we hammered away on the gravel, which was quite washboard-y at times, I was worried about flatting the high-performance summer tires, bending a rim, or what-have you. I much prefer gravel on proper tires! We had a rock take out the O2 sensor for the wideband tuning and Fuel-Injection…but not to worry, the rally bug has a second unit installed “just in case”. We switched over to sensor B, and continued our drive. The Fiat dashboard rattled loose, the air filters on both cars were filthy, and both cars noticed a few running issues on the other-side. No worries, a bit of clean pavement should clean them out!

Day three didn’t start nearly as well as I had hoped. In fact, the rally bug wouldn’t start at all. We swapped coils, we changed fuel maps, we tried starting fluid…nothing. Finally I tossed a tow rope on it, and go the sweep truck to pull me, just to see if we could get it to kick over. In less than 10ft of tow, it fired right up. Hmmmmm….that’s weird. Whatever, it’s running, the organizer is an hour behind, and we have to get to the finish! We hit the road, and I put my foot down to catch up. Along the way we passed a Datsun 1500 which had a battery/engine fire. They were okay, and cars behind us would have the spares they needed, so we pushed on. At the mid-morning stop, the car started on a quick bump-start, but sounded “off”. I was stressed, and it sounded like it was running on three cylinders. Rev it up, and it cleared up, and the computer showed good fuel numbers…so run with it!

At one point we lost the signal from Oxygen Sensor B, but as the fuel map was quite well developed at this point we simply switched the computer to run off the map only, with no adjustments.

An hour and half down the road, we pulled over to help some guys who had made a wrong turn. A waft of smoke passed the car as we did, and I pulled over expecting to find I sucked a valve cover gasket or something and had some oil burning off the exhaust. Instead, I was greeted with shouts from the other car saying “Flames! You’re on FIRE!!” Whoa! Jumped out, ran to the back an instantly knew what happened.

Yes, there were 8” flames coming out of the rear apron/under the fender, and I couldn’t blow them out, but it wasn’t fire extinguisher worthy. “water, get me a water bottle!”. I put the fire out, and assessed the damage. An exhaust gasket had burned out, and we spent an hour and a half ejecting hot exhaust right against the apron. Burned the paint, the the engine seal, the fender welt, and all of the wiring to 02 Sensor B. Oops. We removed the offending parts, zip-tied the engine lid up, and hammered onto the finish! None of this waiting around for a tow :P



About 35min down the road we started to see an oil-stream on the highway, and turning the corner found our friends in the Fiat on the side of the road. I guess our gravel excursion had loosened the drain plug, and they lost all the oil out onto the highway on day three. Noticed/saved it before any engine damage…and after we all searched through our spare parts, a thermostat was found that fit…and it was refilled with oil to continue to the finish!

Since returning home from the Silver Summit, I’ve been battling the Rally Bug to find the no-start issue when it’s cold. I identified a weak spark, and started to chase down the possibilities. New coil, cap, rotor, plugs, plug wires, pertronix…and I finally hooked up the computer controlled ignition system to see if I couldn’t chase it down. I’ve tried everything! And then, it hit me…Dave, when was the last time you checked the valve adjustment? The car has done roughly 20,000km since the last valve adjustment. Uh, oops. You know, compression is a pretty important part of the whole combustion sequence.



Yeah, so I’m an idiot. But the car runs WONDERFULLY now. I’ve spent some time tuning it on my sea-level tune, and it’s now at the point where you simply start the car and it idles right away. I’ve leaned it out a little, and between fuel tuning and spark tuning I’ve found more power and better fuel mileage.
__________________
'71 Type 1 - Rally Project
'58 Type 1 - I bought an early!?!
'73 Type 1 - Proper Germanlook project
'68 Type 1 - Interm German 'look' project
'75 Type 1 - Family Heirloom
'93 Chevy 3500 pickup - Cummins Swap
Reply With Quote