Join Date: May 2002
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Trip report, performance gains!
I've been doing some traveling in the zuk lately and have made some relatively minor changes and noted
some surprising results.
One, gas is everything to these mouse motors. I started the zuk on Union 76 when I first got it to help
get it through smog. After that I gradually moved from premium to mid grade down to low grade with no
noticeable ping. I also moved to Arco and even Quick Stop as that was the cheapest gas around, and
since it didn't seem to matter. The mileage didn't seem to suffer and the felt power was the same.
It has always had an occasional miss that I sometimes attributed to carb icing, and adding gas line
antifreeze seemed to help. Most gas line antifreeze is alcohol, so I would think gasohol would do the
Recently I switched back to U76 to see if it got any better mileage and was surprised to see it increased
by 4% on average. Cost was only 2% more so that's a no brainer. What I didn't expect was the
elimination of most misses and loss of power spates. It really ran better. I tried chevron and it does
NOT run as well for power, especially in the hills. I must note this year U76 removed MTBE out of its
gas and is now gasohol. That may be part of the difference between when I first got it and now.
I also recently switched my air box from hot air setting to cold air since the U76 seemed to be running
so much better. Bingo! It made a HUGE difference, probably more than the gas in power. And added
some MPG. I can't say for certain how much since I have not been on my usual commute since the
change. But definitely better, a couple of MPG better, than any previous trips. So much better power
that I was able to pull ALL the hills to Mt. Shasta in 4th gear, instead of 4-5 grades requiring 3rd. Even
locally, one hill I NEVER pulled in 4th even empty of cargo, I pulled in 4th WITH CARGO, lots of it.
( I'll post pics of the cargo box, cargo rack and fully loaded (the springs were ¼" from bottomed…))
I also noticed weather/geography has a marked effect on useable power. Very marked.
In the bay area the air is relatively moist. In the Central Valley it is very dry most of the time. In the bay
area I could cruise at 62-65 most of the time (except when the dang miss hit.) Out in the valley, especially
on hot days, that would fall off to sometimes 50-55. Ugly.
Well, I didn't believe it. I was cruising at 65-70 going north even with the dry air. Coming home the valley
got some moisture from a recent front, and I cruised home at 65-75 and I didn't have the pedal mashed to
the floor as usual. I was passing trucks at will (when sometimes I would fail a pass due to not being able
to break the turbulence peeling off the front of the truck). Not this time! It was running so well I am
having some second thoughts about the engine swap (shallow ones for sure! I want that diesel!).
I am going to look at making up a pressurized water vapor injection system into the carb intake. This is
too good to pass on….
Now keep in mind I am driving a stock 1L 84 410. No 5th gear, and only 45 stock Hp with 135K on the
I guess my real point is, for those having power issues with your 65HP 1.3's look to the basics.
Keep records and compare.
Gas, compare brands. Use several tanks from each to absorb anomalies.
Stay on top of the tuning
Verify the dist/cam timing
Shim the dist gear properly
Adjust the valves right. (I still haven't done this!)[img]images/graemlins/spank.gif[/img]
Make sure the hot air flapper is working (Mine is manual, the Samies are not)
And as always, the cam/crank timing.
Anyone else have comments or similar observations?