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Discussion Starter · #1 ·
so i installed my air fuel guage and the car leans out to like 1 or 2 bars between 2500 and 3500 rpms. alot of times it will buck and hesitate too during that time. when it bucks the gauge shows 100% lean.
after 3500 the guage goes to full rich and the car takes off.
what could be the casue of this problem?
i have a new o2, cap, rotor, plugs and wires, fuel filter, blue cts
 

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Re: leaning out 2500-3500 rpms (TBT-PassatG60)

what boost rate are you running? you have a no-lagv3 chip right?
 

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Re: leaning out 2500-3500 rpms (TBT-PassatG60)

and yeah think long and hard about the boost level at that full lean (16:1!) . Cleans off the pistons right good.
best method to remove it is to go no lag and 3.5bar fpr and 65/68mm pulley. That will make the car well fun as hell and eliminate that.
 

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Discussion Starter · #8 ·
Re: leaning out 2500-3500 rpms (mrkrad)

are u serious this is normal? becasue the car bucks and hesitates too.
 

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Re: leaning out 2500-3500 rpms (T34418L31)

well bucking isnt.. hesitation is..
but when you say bucking you mean the car is uncontrollably jumping up and down or, just a slight jitter?
 

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Re: leaning out 2500-3500 rpms (LagunaSecaBlueMK3)

IF it kicks it's back feet in the air then it's definatly bucking

sorry i couldn't help it.

i unfortunatly have digilag as well

and neeed a chip made soon....
 

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Discussion Starter · #11 ·
Re: leaning out 2500-3500 rpms (charrington)

i advanced the timgin a little bit and the problem seems to have gone away could that have been the problem?
i was getting like 9-10 hg vacum at idle and now im getting like 15ish.
the car seems a bit faster too lol.
 

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Re: leaning out 2500-3500 rpms (T34418L31)

that is logical. more timing uses more octane to produce more peak cylinder pressure. This is where a new knock sensor helps, but pinging means you have gone beyond the scope of the knock system.
It may not be a bad idea to have a mechanic person with a nice adjustable timing gun check yo settings. I have ghetto set the timing myself on accident to 12BTDC before which is unreasonable. But then again i have the tool to adjust the timing relatively back with the ecu software so.
We've come to find that +1 or +2 degrees on street gas is safe, anything more and you should discuss having such changes done in the code. This is because what you are doing is making a broad sweeping change.
The engine may want to ping at (any) rpm, but if it is tweaked in software you can remove timing at a particular point while leaving the rest of the timing curves alone.
In an ideal world you would have time to make 16-20 dyno runs to extract the max timing possible safely (watching a/f), its alot easier to hear pinging with the hood up and sitting on a dyno.
Sometimes a car can take more timing, sometimes a car can't. Which is why i say 6BTDC factory. Some cars might have so much crud on the pistons from being poorly pm'd you have to back up off the **** put your cup down.
My best advice is to use good consistent gas stations, carry that crows foot wrench around in case you are in east bumble-****, and get stuck with rotten gas.
Whenever my vw decides to show up at the house again the low/normal octane chip program may commence again. I will be looking for people in octane challenged areas (co,ca,canada areas) to try some things out since 90-91 or stepped on gas like am/pm crap can be tested. With these higher gas markets prices with no end in site, i think the ability to use crap gas and have SAFE emergency passing/power is essential.
Also the nitrous heads may find an 87 octane map essential to a 75-100shot of nitrous for safety. The hardware to do the switch chip consists of one switch single pole, a wire thats behind your cluster somewhere , and a wire to the TB ground point. Maybe $5 bucks if you go all out.
I think it would be nice for everyone given these hard times and insane gas prices, if you are in pinch or on a long road trip where peak whp isn't a factor.

yellow wire going somewhere behind fusebox --> POLE-> switch -> pole -> ground point on throttle body

maybe KK will be the ones to test the 91 octane (and 93) and roll them into production as defacto-standard stage 1,2,3,4, if i can get dave to do some testing

testing 87 octane sucks, its like well slow, but i'll be damned with the gas prices these days.
I'm seriously considering putting the fbody away for daily driving (10-11mpg city) and switching back to the rado. going 110 miles then paying 31.50 for a refill is not in my poor broke ass budget right now.
(mullet mobile does get 24mpg freeway cruise due to agressive cruise control timing and target air fuel ratio) not bad for a stalled/cammed/geared automatic 3400lb tank.



Modified by mrkrad at 1:00 PM 5-23-2004
 

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Re: leaning out 2500-3500 rpms (mrkrad)

i'd do some testing for ya

damn are 91 octain gas

my setup is a little more exciting than a standard uprgaded system though
 
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