Bezinpumpe Steuerung MA70

2. Stufe?

 

24v anlegen

 

2. Stufe wäre mir neu... An oder aus, mehr kann die eigentlich nicht...

 

Der Meinung bin ich eigentlich auch...

 

bau eine 2. Pumpe ein

gibt es wirklich eine 2. Stufe???

[ 01. Januar 2003: Beitrag editiert von: Black Devil ]

 

Hallo Conne,

Benzinpumpen bei Saugrohreinspritzmotoren arbeiten meist mit einer Fördermenge die etwas größer ist als der größtmögliche anzunehmende Verbrauch.

Der Druck in der Sammelleitung am Ansaugtrakt wird über ein Überdruckventil geregelt, welches den Druck Konstant hält, egal ob Leerlauf oder Vollast.

Ein Verstellen diese Druckreglers und der Pumpenfördermenge ist nicht anzuraten, da dies weder zu Verbrauchseinsparung noch zur gewünschten Leistungssteigerung führt, sondern nur zu Störungen der Einspritzanlage.

Die ganzen Komponenten sind alle aufeinander abgestimmt.

gruß

dennis

 

In der Tat wird hier die Benzinpumpe umgeschaltet, was aich auch noch nicht gesehen habe, aber irgendwann ist ja immer das erste Mal.

Die EFI-Steuerung gibt an Klemme "FP" (Fuel Pump) ein Signal aus, welches das Relais zum Umschalten bewegt.

Der Vorwiderstand hat 0,7 Ohm laut Handbuch. Eine große Drehzahländerung wird es also nicht bringen.

Es hat auch nichts mit dem "FC" (FuelCut) zu tun, das haben nur die Turbo-Modelle.

gruß<br />dennis

 

also ein zweistufiges relaise ist das nicht... sondern einfach ein relaise mit wechselkontakt...

ich vermute eher dass es eine anlaufschaltung ist damit die pumpe langsam startet und nicht gleich volle last fährt...

aber wenn man den rest der schaltung nicht hat (so wie ich) können das nur vermutungen sein...

zumindest habe ich noch nie was davon gehört dass die pumpe in zwei stufen arbeiten soll...

 

Sehe ich so wie Lucky: nicht 2-stufig sondern ein stinknormales Relais mit Wechselkontakt. <br />Kontakt nach links: pumpe läuft für sich,<br />Kontakt nach rechts: Pumpe läuft in Verbindung mit dem Widerstand.

[ 03. Januar 2003: Beitrag editiert von: Andreas-M ]

 

und für die des Englischen mächtig:<br />The power to the fuel pump is going like this:

First the main power cable is fused by the EFI fuse, this fuse resides in the engine bay fuse box and is 15A. This fused power supply cable then goes into the relay unit called "EFI Main Relay". This relay unit is in the fuse box as well. It's the rightmost relay, the one to the left is the headlight relay. The coil of the relay unit is controlled by the "M-REL" signal of the ECU. This wire is Black-Orange on all models (hopefully ;-)

The switched power now travels to all EFI related items in the car, including the "Circuit Opening Relay". This relay is located at the passenger side kick panel. Note this is the drivers side kick panel on right hand drive vehicles (England, Australia etc.) The relay prevents the car from starting when it is still in gear (automatic) or declutched it (manual). It stops the fuel pump as well when the engine died (savety). The wire from the EFI main relay to the Circuit Opening Relay is Black-Red on all MK3 models.

After the circuit opening relay, the power cable travels on to the "Fuel Pump Control Relay", residing on the right hand side of the car under the hood, about the same position as the 3000 pipe, but then on the fender wall. (Near the suspension connection!) The wire is colored Light Blue - Black. This fuel pump control relay directs the current to the fuel pump either onto the black wire to the Fuel Pump Resistor or directly to the fuel pump with the Black-Red wire. The relay unit is controlled with the yellow wire coming from the ECU (signal FP).

The fuel pump resistor is quite a big resistor with a big cooling core on it. It's located on the right fender wall as well, just near to the fuel pump control relay. The one side wire is black coming from the relay, the other side is black-red and joins the black-red wire from the relay to feed the fuel pump. The resistance of the fuel pump resistor is approximately 0.7 Ohm. Yes, I know, that's nearly nothing. The only thing I can think of is it relaxes the fuel pump a little bit. Under (very) high pressure, the pump gets a shot and the relay closes the resistor.

What can we conclude from this story? Well, one thing for sure: Before current gets used in the fuel pump, it travels a damn long way thru all kind of wires. These wires have their own resistance as well, which is absolutely not helping the fuel pump perform it's highest potentials. I know some people who solved this problem very easily. The solution is taking a new wire directly from the battery (or the alternator) to the fuel pump. Mount a new relay (a Hella relay for example) in the trunk near the pump and use the original wires for the fuel pump as the wires to control the relay. The new wires will be switched by the relay unit to the fuel pump. Now the fuel pump will get at least 12 volt, but 13.5 volt is seen also at this point with the alternator running. The pro of this modification is, the fuel pump runs on a higher voltage than normally, so the pump can flow more fuel. Most pumps are designed for anything between 11 volt and 15 volt, but the higher the voltage, the more fuel is pumped. Another good thing from this mod is the stock wiring doesn't get used in this new modified situation, so it will not get hot eliminating the potential danger of setting the car on fire. The 'con' on this story is, the fuel pump gets 13.5 volt under all conditions. So it flows way too much fuel, which all gets returned by the return line. The life of the pump can be shorter indeed, as it has to work 'harder'. A side note has to be made: I don't know how the ECU behaves in respect to this "FP" signal, controlling the "fuel pump control relay". I will mount a led in my dash some day soon, to monitor this signal. If people know under what conditions this signal is engaged, please send me an email at: [email protected] The thing we all can be sure of: When modifying the car heavily (as is the case when you need a new fuel pump) the ECU will not be able to control the 'FP' signal accurately, as the situation has been changed.<br />Furthermore, a lot of my sources say the Walbro fuel pump is designed to run on 12 volt (13.5 volt) only and does not perform well with the fuel resistor. This can easily be found out, so you can always remove the fuel pump relay / short it. Or short the fuel resistor.

So the decision we have to make here, before we start our work on replacing the fuel pump is: Are we going to run the pump directly from the battery (or alternator) or are we going to use the stock wiring. Well, I think both options have their good and bad sides, so why not make use both the options good sides? My suggestion for the fuel pump upgrade is replace the stock wires with thick (low resistance) cables. Only the important wires of course, starting with the black-red wire going from the relay (resistor) to the fuel pump. This is quite some work but it is indeed the best solution. In case we need "always" 13.5 volt on the fuel pump we can always reroute this wire to another location or we can make a manual (in dash) override switch to lock the fuel pump control relay. Or we can even get rid of all fuel relays and fuel pump resistors (the thing I am planning to do).

Copyright www.supras.nl

Gruß Christian

 

also wissen holländer auch nicht wozu der widerstand gebraucht wird...

 

Wenn man sich so mache Merkwürdigkeiten in der Supra-technik anschaut, dann glaube ich das wissen die erfinder dieser "schaltung" selber nicht so genau...