Hi there,

Every time the boost goes to zero from vacuum my AFR goes lean and beyond that. It feels like a fuel cut or something. The only way to get rid of it is to let the 2nd injector give some more fuel at this moment.
Now you are thinking...now what's the problem...
The problem is when I am driving with 140km/h cruise the extra injector is on and the engine goes very storch (rich)

Maybe my hardware install isn't right and maybe I change it today.

Connections now:

Fuel line goes to the 2nd injector, then a T-connection, the T goes to a Power boost valve pressure regulator, The otherside goes to the std. injector and the output goes back to the fueltank.

Pressure main fuel line is 4 bar and the vacuumhose should push it a little further on Full throttle.
Pump is 148L/H @ 5 Bar.
The std injector I don't know but it's on the max otherwise the cold start is not right (to much fuel)

If I change it then I will try this:

Main fuelline to the std injector T-it to the 2nd injector. Retour from the std injector goes through the PBV regulator back into the fuel tank. And the pressure on 3 bar.

Maybe it give to much fuel in low RPM and deflection but that should I compensate with the Piggyback (SMT-6)

The std injector should be able to run the engine to around 0.2 0.3 bar right?

And if this isn't the solution is it possible to place a LED light over the injector leads so I can have an indicator if it stops at that moment?

Greetzz Dennis

This afternoon I connected the fuelpipes on the second way. The injector gives more fuel. That's oke but again around 0 Bar the engine stalls and goes lean.

When it's near to 0 it drops to 12AFR (at this moment) and a little after that it rising to 21 on off on off. And when I put the throttle to 0.2 bar there's nothing wrong :bang: :bang: :bang: :bang:

So why does my standard injector fails at 0 bar.
Or the 2nd injector is running the whole engine on boost and the standard injector is off. But without 2nd injector the car is able to run the engine only it goes lean.

Somebody told me once that Tuners like novitec the MAP sensor limits cause the ECU isn't able to se possitive pressures. Is this right?

The SMT is able to change the maximum value of the MAPsensor in Volts. Now it's unlimited (10V) I can change it to 5V or lower and see if the ECU stops injecting fuel or not.

Maybe the limiter is broken or something.

Normally (last year) I was able to drive without the 2nd injector only the fuel was lean. Now the engine stalls and fires and stall and fire .... 21....10 ....21....10....21....10....21 AFR.

I hope to find out soon

AFAIK you need to limit the voltage seen by the ECU 2 5V's otherwise its thinks something is wrong, over here they are know as FCD=Fuel Cut Defenders (Van Aaken call it a BDL=Boost De-limiter)and are available to buy from a few companies that deal with turbo cars.

Aaron.

By asteris in another topic:

After installing a turbo, MAP sensor reads and sends positive pressure values to the ECU, which thinks this is an error and stops injection and flashes injection light. You must trick ECU so it doesn't get the positive values, just up to zero.

This is done either by reprogramming the ECU, or by installing a small circuit between MAP sensor and ECU, that limits values to zero.
In case there is any interference to the cabling of the MAP sensor, there should be a small box somewhere under the dash. This box should have one or two pots that control the signal passing through to the ECU.

My car was also facing the same problem, car stalled for a while when the turbo kicked in, ECU stopped the main injection, light was on and for a while, only the extra injector was on. Small adjustment on the above mentioned pots solved the problem.

So it is a MAP positive pressure faillure.
Only my second injector is so big that it is able to run the whole engine at boost
I think the injector light is dead in my car cause I never have seen it burn. Even when I disconnect the complete TB

And now Solve the problem.

On the perfect power forum they say you can limit the MAP voltage and at this way you can rid of the FCD.

A long time ago someone told me that you can also place a 4.3V Zener Diode between the MAPsensor 0...5V signal and ground.

After a little google-iing I found this

http://www.thedodgegarage.com/turbo_map.html

Maybe my car is using this only it's broken. If so maybe I can find and replace or try it with the SMT software.

Try this one, or ask a friend with basic electronics skills to do it for you.

http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

4.55V is the top voltage the ECU expects. More than that and ECU shuts the main injector and flashes the warning light at the dials.

don't be using a zener diode to limit it, thats a very.. poor way of doing it.

http://www.graphics.cornell.edu/~v/fcd/

yeah oke I know. but does it work?

first I try to set it with the SMT...It should be working. Only I need somebody to drive my car cause my leg has a surgery.


4.55 V oke nice to know.

Do you also know what type of MAPsensor it is? up to 1 bar, 2 bar or....?

[edit] Search mode on: 100KPa = 15 PSI or 1 bar and tis is count from sea level or from realy 0 bar[/edit]

Cause changing the map sensor for a bigger one and change the fuelmap gives the result that the engine can give more fuel and fuel with boost.
espacially with a bigger standard injector or higher fuel pressure.

All MAP sensors work from 0.5 to 4.5 V (zero to full range of absolute pressure). Ours is an 1 bar and if you connect a volt meter between MAP signal wire and ground, you will get about 0.8-4.5V (decellerating to full throttle). If you use the 2 bar, you will get somthing between 0.8 and 2.5V, which won't sound right to the standard ECU.

Uno turbo and Punto GT use 2 bar MAP, and if you can get an ECU remap along with this MAP and a bigger injector, you'll get the best results from the car.

I use an FCD similar to the one described to the link and works ok. Although i need to lower it at 4.45-4.5V, as sometimes over 4.55V values escape towards the ECU and get split second hesitations and warning light...

I'll keep it short but......


Problem Solved:worship:

It was the FCD.
Did limit the MAP-voltage by using the SMT-6 settings.

This problem caused me a lot of trouble last 6 months and I did even knew it :bang: