Members Page/Kevin Black/VWGTI Another

MembersPage/KevinBlack/VWGTIAnother (2008-06-21 07:26:39)

Project page for (another) VW GTI/16v swap, Turbo

Car: 1994 VW GTI

Engine: ABA(8v)/9A(16v)

ABA (8v) block, crank, 60-2 trigger wheel, Ignition Coil, Ignitor

9A(16v) Head, 16v Distributor(modified for one window)

Built motor (forged pistons/rods) Garrett GT35R .81 a/r T4 turbo.

Custom EC36/EC18 Wiring harness

VEMS v3 webshop assembled

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Update

Many, Many problems!

Twice, shortly after making a change in Megatune, the ECU "locks up" and causes the injectors to stay open and fuel pump to run, hydralocking the motor. In my case it cost me a USD $280 Bosch LSM11 O2 sensor!! Also new oil for the engine (twice), and several hours lost (work and sleep).

- What could cause the ECU to do this? How can it be prevented?

- After turning the power OFF for a few minutes, everything was fine the first time, however the second time I think the ADC chip was damaged.

- I now have no 1) EGT 2) Launch Control stuck ON

- I am using an external MAP sensor, how is this still working?

The wideband O2 readings are OK at idle and low engine RPM, but jumps around greatly at medium RPM and higher, making the sensor unuseable. The pumpzero_pw and Nernst values were used as supplied with the VEMS, and the sensor was calibrated to 20.9% O2.

- What could be the cause for this problem?

of possible note is I used the Fuel Injector relay output (terminal 87, shared with fuel injectors and the FJO fuel injector driver, to power Pin #3 of the Wideband O2 Sensor.

- possible interference by using injector power instead of 12v ignition?

- To allow the car to be tuned, I used an analog input for my Autronic exhaust analyzer. I set the analyzer to 0-5v, 10-15 AFR so I could view the Megatune logs in voltage and add a "1" to get my AFR. However I could not do this after the ADC chip was damaged.

What does the "Map Multiplication" in Megatune do exactly?

- I thought the pulsewidth would be multiplied "behind the scenes" and the fuel VE table would be "flat", but it is not working on this engine (VE value approx. 50% at 40 KPA, 200% at 250 kpa)

The car runs very well when it is running.

The TPS Enrichments are not working well (often adds fuel on small throttle transitions) and I need to work on the startup a little.

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Car is up and running on VEMS

Currently using 60-2 crank trigger only, semi batch fire injectors

Rochester 1000cc injectors, FJO external Injector Driver unit

VEMS 400 kpa External MAP sensor

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VEMS #1724 Order Specs:

Assembled v3.3 controller

- 1-wire interface: no

- Flyback: 30V flyback

- ignition driver: 4

- Knock and EGT: yes

- LCD connection: yes

- MAP connection: offboard

- primary_trigger: VR

- secondary_trigger: HALL

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Build notes:

Board_version=v3.3

Serial_nr= 1724

pump-= 4.12V

wbo2_pump_pw_zero=0x67 (103 decimal)

wbo2_nernstdc_target=0x86 (134 decimal)

pump+= +0.9mV/200 Ohm

AREF=4.9V

(C103=1nF, no D100)