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Things are a bit slow... so heres the writeup Ive been talking about so long: OK. I've been promising this write-up for while now. I've done a bunch of hillclimb's in my FI Square but "Hill" in the east here means a 3800 foot summit! On the way to Parma we all cruised into Cheyenne WY late in the afternoon. I noticed my throttle way down and knew that we must be climbing but the climb was subtle. Next Morning the hill out of Cheyenne was a beast! I had my hammer on the floorboards and it just didn't seem to be going as it should. was this in illusion as to how steep we were climbing?? We'll we stopped for some pictures and a rest and I looked things over. all seemed fine, and was running cool, but I soon saw the marker that told us we were over 8000 feet!! I felt much better after a nice calm "Your Fine" from Jim Adney. but when he blew past me with an AUTOMATIC I started feeling that all was not well again. Runs fine. cool, just No Balls! That evening we had one of those nice thick technical conversations about just how the FI works and why the altitude was essentially putting a wood block under my accelerator! Thin air. not allowing enough air to enter the IAD and therefore having a much higher vacuum in there under Full throttle when compared to a constant (pressure in the bellows of the pressure sensor) than it would at sea level. This created a condition that made the pressure sensor never give the control unit the signal for the throttle I desired. And of course my vacuum gauge is measuring vacuum as compared to the atmosphere AT ALTITUDE so is giving very misleading readings. Have I got this right Jim? The result of all this was a slow go but EXCELLENT gas mileage, and I didn't seem to have any problems with the poor quality western gas. I'm set up to use 92 Octane with 7.7:1 and my FI setup. but never noticed any knocking or pinging with the 89. I'm running a stock 73 injection system with a 69 pressure sensor. which I always preferred due to its being the most evolved and the A sensor removed the hesitation off the line by running things a bit richer. I now realize just how smogged things were getting by 73 and I do think I will convert back to the stock D system for 71 and run the fuel pressure higher. I just can't let myself get passed by those Automatics! J I never felt consistency with the D system when I ran it years ago but I rather expect that may have been due to a flaky temp sensor and perhaps oil in the pressure sensor. The return trip took me through the Colorado Rockies. made the Teton pass look like an anthill! Once over 10K feet the thin air really made itself apparent. I had about half the power I did at sea level and a strange thing would happen with the cooling. I could keep the pedal mashed at 35 in third (about 2500RPM) and the engine would be smooth and gutless but nice and cool. with outside temps around 50F. When I downshifted to second to get more power and got the RPM up for more power the oil temp would suddenly shoot up 30degrees or more, I got more power but not a lot and it was still smooth. Upshift again and it would suddenly cool again. I've never seen such sudden and drastic changes in engine temperature! My theory on all this is that since the air is so thin up there that there is little cooling it can do even when its cold out. Low RPM means low HP output with the FI and less heat generated, higher RPM would give you more HP but more heat too and the thin air just couldn't carry it away, but boy the change was rapid! I remember Shad Laws saying that the head temperature would skyrocket when floored at altitude even though the oil temperature was low. but I didn't ever hear any knocking or see any sign of it. I Don't have any head temp gauges though (WOW! a gauge I don't have!) So I couldn't say for sure and I sure hope I don't find any cracks with the next overhaul. But since the FI basically puts a block of wood under the accelerator why would the heads run hot?? The car made it over the 11,800 foot mark just fine though and then the 30 mile or so decent DOWNHILL into Denver (hard to believe its still a mile high!). We were all doing about 85 or 90. nice quick paced ride but even with that high speed stint down I set a gas mileage record of nearly 35MPG with that tank! I didn't beat Sophy. but seeing the mileage that high with my foot on the floor so much still seems hard to believe! Lastly, and as Jim A will attest, I spend too much time looking at my gauges. but I just cant help it! Part of it is Psychological. I changed the Tee that the temp gauge is mounted on from Cast iron to Brass, which moved temp readings up about 25F and made for much quicker response. The down point being that my mind is now seeing that needle nudging into the yellow at 205F and even though that is the engine temp it has run at for its whole life it makes me nervous! Add that to being several thousand miles from home with an engine at over 80Kmi cruising in heat I've never driven in and my heads a bobbin like a Weeble! Perhaps I need to mount my gauges like Toby's, on the Dash. Keith Keith Keith Park Top Notch Restorations topnotch@nycap.rr.com 71 Squareback 65 Notchback 65 Squareback 75 Opel 87 Golf 88 Rx7 10th Anniversary ------------------------------------------------------------------- List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org