[Weird voltage issue]

I assume this happens when power is on and engine not running (since voltage is 12,5)?

I suggest you double and triple check your wiring, turn off all analog/digital inputs and auxoutputs. If u have relays connected to auxoutput remove those. '

Because if u have a relay connected to auxoutput and straight to battery + you will have a backfeed problem. Atleast when turning the power off @ the +14 terminal.

Might not solve your problem, but worth a try. Good luck

Will do!

Here's a link to a screenshot from the statistics, maybe the high voltage has been a reason for such a strange numbers.. :?

http://i87.photobucket.com/albums/k133/ ... enshot.jpg

[Weird voltage issue]

groundings ok ?

Should be, as I take the ground from power grounds and multimeter shows readings as they should be.

[Weird voltage issue]

Okay. Among the other Vipec related issues, there is a weird voltage issue going on. After a while the power has been switched on, the ECU starts to see 0 voltage or 24,5 voltage jumping around. I have measured with a multimeter from the +14 input wire and it sees a constant 12,5 voltage as it should be. What the heck could this be... :shock: ? The system cannot generate such a voltage in anyway and in reality there is 12,5 voltage in +14 voltage wire.

EDIT: A backfeed issue maybe... :roll:

[Cam sync question]

If it is high for half an engine cycle and you have a multi tooth missing trigger wheel on the crank then you can use Cam Level for the sync.

This does require a hall or optical sensor on the cam.

Yup, I've got 60-2 as trigger pattern and hall sensor on the cam.

Did a quick test and it seems that Cam level is the right set up, as there was signs of life in the engine, but could not test any furter since the battery run off. It seems only trigger offset need to be set on right position and then it should be ok.

I suggest to add to the manual (at initial start up section), to check the right cam sync setting and guidance upon which cam sync option should be chosen.

[Cam sync question]

Hi Guys,

Just trying to figure out the differences between different cam sync settings. I am using V88 as ECU.

I'm currently having "Cam Pulse 1X" as a set up in software but having small issues with starting the engine (actually the car does not fire at all... even though the coils fire as they should under the test mode). I just figured out that the cam trigger / wheel is actually "half a size of a cam". Should I then choose the cam sync as "Cam Level"? I suppose the signal is high for 360 degrees and low for 360 should such a cam sync be used?

Thanks!

[Newbie asks: open loop fuel tuning]

OT: question, are you by any change from finland? i would have send PM but its not enabled in the forums.

Yes I am..

[Newbie asks: open loop fuel tuning]

The engine needs to be tuned using a Wide Band initially.

When tuning is complete, if you decide you wish to run a different A/F ratio at a given RPM/LOAD point,

then you change the Target Air Fuel table to the new desired A/F Ratio.

Back ground mathmatics adjusts the values automatically to change the fuel table to match the new Target A/F Ratio.

You do not need a WB A/F meter to be connected to achieve this as long as the engine was tuned correctly with a WB initially.

Does your engine run a single throttle body or multiple throttle bodies.

If you have multiple throttle setup you need to use TPS as your load axis, however i have used a vacuum balance plenum on multi throttle engines and used MAP as my axis.

I have tuned engines using MAP with very low vacuum readings without issues.

If you find using MAP or MGP as your load axis gives you issues, then use TPS as your load axis and MAP or MGP as your load axis on your Target A/F table.

Okay, thanks!

Just got an impression from Ray's explanation that while using open loop -method, just tune the engine to 14.7 AFR at 100 kpa load, the math would do the rest and the ECU would then use the AFR table to calculate the sufficient opening for the injector. The reason I put up this thread, was that different size of turbos pumps air into the engine with various amounts, meaning that one would pump 60 lbs / min and other 80 lbs / min at 300 kpa level, how would the ECU determine the required fuel just out of the MAP which could be the same using different turbos but the amount of air entering into the engine would differ greatly between different turbos used in the same engine, but giving equal load and airflow at 100 kpa where the 14.7 AFR was tuned as starting point for the calculation.

[Newbie asks: open loop fuel tuning]

Okay, where to start with:

It's time to fire a Volvo V40 with a following mods (a rough list)

- Vipec V88

- Volvo B4204T3 engine block, with Darton sleeves, 84mm bore; 1998cc total displacement

- JE pistons and total seal 1st capless rings, 10.2 CR

- Cams: 294 degrees at intake (measured @ 1,27mm valve lift), 12.55mm lift, 284 degrees at intake, 11,8 mm lift. Intake valve open 4.2mm @ TDC and exhaust valve 4.0mm @ TDC.

- Holset HX50 MFS, (67mm compressor wing, 72 mm exhaust wing, #19 exhaust housing)

- 4x1200cc Bosch EV14 + 4X1000cc Bosch EV14

- 2xBosch "044" fuel pumps

- E85 fuel

- IGN1A (aka "034 motorsport") coil per plug

Car will mainly be used in one mile events and occasionally in 1/4 mile events.

As you can notice there is really lappy cams in use and practically only minimal vacuum at idle. I am just in the heat of choosing the tuning method and while browsing through the forum, I saw this topic:

viewtopic.php?f=3&t=310&start=15&hilit=AFR+correction

This open loop tuning method would perhaps suit my needs. However I'm interested to know that how in heck the ECU can calculate the need fuel under different load as the AFR table is the look up table? If I tune the engine to 14.7 at 100 kpa load, (fuel table number 22 at AFR 14.7 and then set flat over the entire fuel table) and AFR table is set to 11.8 at 300kpa, the ECU is able to calculate the needed injector opening to deliver the needed fuel to achiece desired AFR at 300kpa without feedback from WB?