solved? was: [16v] hard start, bucking/bogging off idle

[dswalterwi at gmail.com (Don Walter)]

Did you use a special harness to check with the ammeter?  That is how
I have always thought it had to be done but just recently another
scirocco owner said he could check it by using the open connector that
is near the firewall (used for testing) to measure the Air/Fuel ratio.
 Anyone else hear that?  Should would beat having to hook up that
harness or leaving it in and jumpering it.



On Sun, 5 Dec 2004 19:12:00 -0800 (PST), T. Reed <treed2@wsu.edu> wrote:
> My car really pissed me off today.. it did the "cut out in the middle of
> busy intersection" thing, then it ran like crap all the way back home. I
> felt like I should drive it really hard to teach it a lesson, but it would
> just buck and slow down whenever I hit the gas.
> 
> So... despite 28 F, darkness, several inches of snow deposited on several
> inches of ice, and a 10 mph wind, I decided I was going to go out and find
> out what the hell was making it do this.
> 
> Popped the hood, began looking around. Discovered that the coolant
> temperature sensor wire insulation was cracked and the wire had bent at a
> 90 degree angle because of the lost strength. It was all nasty and
> corroded. Decided that it would be good to replace, so I got my inverter,
> soldering iron, and a desk lamp (had to improvise since I'm away from all
> my tools), and soldered a new tail on the wire. Only after reconnecting
> it did it occur to me that this was the sensor for the GAUGE!! Ugh, I need
> to work on my car as often as I used to so I'll start thinking these
> things through...
> 
> The one for the F.I. has an interlocking 2 wire connector. Oh well, I
> guess having accurate engine temps in the cluster is important too.
> 
> Frustrated but numb from the cold, I realized it had been a while since I
> checked/set the dpr current at idle. I think it was April or May.. so I
> hooked up the ammeter, dpr harness, and got my 3mm hex key.
> 
> Checked the current. It was something like 17 mA, then 15 mA, then 10 mA,
> then 6 mA, then 2 mA, then 17 mA, and it kept repeating this cycle. The
> low battery indicator was flashing on the meter so I replaced it and tried
> again. This time I got a steady 5-6-5-4-5-6-5-4-5-6-5-4 fluctuation.
> 
> Decided to try setting it to the stock 10 mA +/- 1 mA. After doing so,
> unhooked everything and went for a spin.
> 
> Wow, lots of low end torque now. I could spin the tires (on snow/ice of
> course) in 1st through 4th just by giving it a little gas. The car feels
> distinctly different, so I proceed out of the parking lot with caution.
> Drove around the neighborhood, stopping about 10 times... no problems with
> stalling or bucking when coming off idle! Now my biggest problem is
> throwing snow in 1st or 2nd even if I start out easy..
> 
> Did I fix it? I hope so! I won't know for sure until it doesn't do it for
> like a week straight..
> 
> The current theory is.. some things have changed since I last set the dpr
> current:
> - the cat plugged up and had to be gutted to put it out of its misery
> - added an autotech fuel module (disconnected for past few days)
> - new battery cables and grounds
> - car sat for 3 months
> - the temperature dropped (20 - 30 F  vs.  45 - 65 F)
> 
> Somehow, these factors made the idle mixture rich enough to cause the car
> to run like crap.
> 
> Cold enrichment would make an already rich motor richer, which could
> explain why this problem didn't set in until after I put the snow tires on
> (it's been consistently 10 - 15 F colder since I put them on). The sudden
> disappearance of the cat could throw things out of tune too (particularly
> if I last set the dpr current when the cat was still semi-plugged).
> 
> The other corroborating evidence is that despite bucking and bogging
> seemingly at random, the car ran amazing above about 3500 rpm.. all kinds
> of torque. It ran right up to the rev limiter..
> 
> So apparently this craptacular hesitation is what a 2L 16V with CIS-E will
> do when there is proper fueling at the top end, but too much fuel around
> idle.
> 
> Now, with the 10 +/- 1 mA current setting, its going to peter out at 5000
> rpm or so, but be very strong down low..
> 
> Anyway, just thought I'd share the latest development in my quest to make
> this damn car run properly.
> 
> -Toby
> 
> _______________________________________________
> Scirocco-l mailing list
> Scirocco-l@scirocco.org
> http://neubayern.net/mailman/listinfo/scirocco-l
> 


-- 
Don Walter - Waukesha, WI
1986 1.8 16V Black Scirocco
1986 2L 16V Toronado Red Scirocco (under repair)
1988 1.8 16V Toronado Red Scirocco (sold on 3/29/04)
1984 1.8 8V Pewter Scirocco (sold years ago)
1971 Karman Ghia (sold)
1969 Karman Ghia (sold)
1969 Beetle (sold)