Thread: 97 D1 MAF and the fuel pump

Firstly, most dual fuel cars leave the pump connected and running. So when on gas can you hear the pump running? Listen at tank or fuel tank filler with cap removed.

Then check that the MAF is always powered up on both fuels. Probe the brown/orange stripe wire to find out. If the MAF is unpowered on gas then the ECU is learning to ignore it to run. As soon as the petrol comes back on it gets a signal it doesn't normally see, confuses it. So you need to track this power supply and run a new power feed from the live side of the injector cut relay. After a while the ECU will get used to it again.

Thanks Bee utey


I tested the brown / orange wire and it has 12 volts on both gas & petrol settings all the time

The fuel pump does not run on gas at all .... Does not prime either
Only primes on Petrol setting


Everyone loves pics ....




This picture is of ALL the relays I found behind the drivers foot well panel .... I'm holding the BLUE relay socket / fuel pump relay .... They cut the white / purple wire and sent it to the Blue relay in the middle .... This appears to be the power feed circuit for all the gas meter boxes

Notice the "Second" gray meter box?



I'm happy to test further ... but need some instructions ....







This picture is of ALL the relays I found behind the drivers foot well panel ....
I'm holding the actual gas petrol switch meter box







It has this gas adjustment box







The MAF wires have been spliced to the "gas install" harness





The gas system .... It was installed in 2003





Any guesses??



Tiss for the bin

Originally Posted by cucinadio

may seem like the simplist of ideas, .... was all along a set of dud leads...

I wish ......

Cheers
Mike

OK here's my guesses (haven't seen one quite like this but hey I can only try). The grey box should be a petrol start relay. It's LED should light up for a moment during starting on gas. I would guess the twin relays cut the injector negative feeds and the single blue relay cuts the pump. Maybe at the same time but could be controlled separately by the grey box. Peel back the tape and see what is connected to its outputs. The pump relay can be temporarily hot wired or removed.

I would think the mixture controller is altering the MAF readings. I would not trust it without detailed instructions to check it. It shouldn't be hard to reconnect the standard wires. My suggestion is to disconnect it and wire up an Impco mixture controller and oxy sensor instead. It does the mixture automatically.

Anyway I don't like Impco much, it does no good to your low end torque. There is better stuff around. But that's just my opinion I'm sure...

The HoHoHo device can go on ebay, there's one born every minute and you should find ready takers.

Best of luck!

I had a think about your words and then had another play with it .....

Originally Posted by bee utey

OK here's my guesses

I would think the mixture controller is altering the MAF readings. I would not trust it without detailed instructions to check it.

Your correct .... I went and dismantled the center console to remove the box and have a look at the wires .... Rotten thing is a variable pot trimmer for the MAF .... All the dials were set to LEAN ... I turned both dials to MAX ... and presto ... The fuel side now works ...

.... It lives ....

The chap I bought this ride from had no idea about how this car was setup .... and could not explain anything to me ... He just said that the "petrol side just stopped working" ... and I've never seen a MPG box before
Go figure .... It says its a Duel fuel MPG control? ... I thought it trimmed the gas ... Not petrol

Originally Posted by bee utey

It shouldn't be hard to reconnect the standard wires. My suggestion is to disconnect it and wire up an Impco mixture controller and oxy sensor instead. It does the mixture automatically.

Rewiring the MAF back to standard is actually quite a feat for me .... there are spliced wires everywhere in this ride
I have another Disco (wreck) in my yard that has a fairly new gas system and a "Learning computer" ... Will take a picture tomorrow and get your thoughts

Originally Posted by bee utey

The HoHoHo device can go on ebay,

I was gunna post it to you as a jester of thanks ....




Seriously tho ... it's hitting the bin

(could put it on izuzurover's front door step and wait for the yell )







I have never seen so many Fuel saving devices in 1 ride


Totally thanking you .....

Cheers
Mike

Just realised why you are chucking the hoho, it's made of PVC pipe. At first glance I thought there was some stainless involved, nah its just silver paint.

As far as rewiring the MAF I would strip back the covering of the cable to the MAF plug until you could see the original wires again. Then just join across the damage one wire at a time, using solder and heatshrink not crimpies.

Glad it's going, best of luck with tidying it up.

Why all the Discos all of a sudden Mike?????

Originally Posted by LOVEMYRANGIE

Why all the Discos all of a sudden Mike?????

I bought a rolled 96 for spare parts ... Gonna swap the whole drive train into my 1990 RRC

and this 97 model (unlic) was up for grabs for 1500 smackers .... Case of ... grab now / think later ..


.... this leaves me free to bung a paint job on "ol Grey", being the 1993RRC