MembersPage/PeepPaadam (2006-07-06 19:37:17)

Introduction

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Hi all!

My name is Peep Päädam and i'm from Estonia. I have a modified Porsche 931 w/ 2.0 engine using K26/29 turbo. I'm planning to use VEMS Genboard v3.3 on it.


We are installing my V3.3 to my friends 944 Turbo 3.0 (yes, 3.0)

and we're planning to use cam mounted Hall trigger wheel. It's already used on 944T with Tatech EMS and has mounting for two Hall sensors (Honeywell 1GT101DC, datasheet here: http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=solidstate&PN=1GT101DC) and aluminium trigger wheel that has two trigger points per sensor (180 degrees apart, because of the cam mount).

The wiring is already done and we're going wasted spark with Bosch coil-pack (everything already waiting for install).

Fuel injectors are Siemens 780cc High-Z.

Is it possible that someone would help me with setting the constants in MegaTune? Starting values would be:

High-Z, so no PWM-ing:


Yesterday we installed VEMS on the 951 3.0 and the installation process was painless. Calibrated things (TPS, battery etc) and got spark with Bosch 2+2 coil-pack.


Little update.

Got the car running and driving pretty good, though we have some problems.

We can't get the fuel map to suit high and low loads: tuning the ve table doesn't give effect and if we get the AF ratio ok at let's say 0.4 Bar, it will become pig rich on the idle and low loads and floods plugs. To get the car running good at low loads, the reqfuel have to be 2!!

Here's the configuration:

3.0 inline 4 Porsche 944 Turbo.

650cc high-Z injectors

VEMS v3.3 (firmware 1.0.38), 1 Honeywell Hall sensor.


30.06.06

Car runs now pretty ok, but I have the temperature sensors little off: IAT shows 8 degrees higher than ambient and CLT is something like 5 (not verified). I know that I must use EasyTherm but haven't quite understood how to do it.

Sensors are all Bosch, CLT is 944 Turbo stock one, IAT is from Audi (only god knows from what model).

We can't tune it on the boost side before I haven't fixed the temperature thing.

Here are the excel sheet of the temp (both CLT and IAT) sensor impedance measurements: http://www.hot.ee/raceboy911/temp_andurid.xls

And here's the config file: http://www.hot.ee/raceboy911/kert130062006.msq

Second problem is the tach that is reading 2 times lower than LCD and MegaTune. How to "make it right"?


2.07.06

We're having a strange problem.

When going for a drive to tune, we can do it without problems for about 15-20 minutes, after that suddenly AFR spikes lean and no tuning helps that and engine dies.

We have the grounds all ok and checked number of times. Fuel pressure is rock steady also.

What could cause that kind of problem?

Hook up DVM (voltmeter, 20V DC) across the fuel pump and fuel injectors.


05.07.06 Update

Here's the sayng: it's all in the details, isn't it?:)

The owner said the injectors to be High-Z, but after hassling with problems, and checking the impedance, they were 2,8 Ohms (Low-Z) after-all!!

Wonder how the VEMS unit held up this current and not giving up :D

Anyway, we got the car running under 1 Bar of boost yesterday, though with rather strange spark angles: @ WOT 6000 rpm it only wanted 3 degrees of advance, otherwise bit of knocking occured (we listened it with stetoscope of course, not ears, otherwise the engine would be destroyed I guess.

I had an idea though. What is the minimum normal dwell time for the Bosch 2x2 coil-pack? Right now it's 3ms.