[Tragilgas]

Hi

I have a '97 EL Falcon GLi dual-fuel ex taxi. Around 3 years ago when it was a taxi, one of the drivers let it run to empty on petrol, buggering the fuel pump. The owner decided not to fix it, so it's been running on gas only for the last 3 years.

Few months ago I decided to get it running on petrol again because backfires/lack of performance/starting problems are a pain in the arse. When a mate and I took out the old fuel pump, we found the tank was half full of 3 year old petrol :fraz:

I siphoned out the old fuel and put $10 worth of petrol in, drove around with it for a day to let it swish around in the tank and hopefully pick up any leftover crap in the tank, then siphoned that out. The tank seemed clean enough, so we put a new Fuel Mizer fuel pump in along with a new fuel filter and hooked it all up.

I went and put $30 worth of petrol in and gave it a shot, but it was a no go. Tried many times starting on petrol, driving along on gas then switching to petrol while moving, all sorts of things, but still no go.

You can actually hear the fuel pump make a noise when you turn the ignition to 'ON', whether switched to gas or petrol. Also when running on gas, you can faintly hear the fuel pump doing something. But I'm not too worried about these noises, as I've heard of different brand pumps being louder than others.

I'm thinking the injectors probably need a good clean (haven't been used for 3 years), or maybe the old acidic petrol has done something bad to the tank or something in it. Are there any other possibilities, or what sounds most likely to be the problem?

Thanks.

 

[Aussiblue]

Most likely the inline fuel filter is blocked. Change it. Other items that may fail with non use include the diaphragm in fuel pump (did you change the fuel pump - if not you now may need to) [Edit: oops missed that bit about the new pump 1st time], O rings on injector, regulator and the fibreglass filter sock on tank pickup. BTW siphoning won't get the gunk out of the lowest point in the tank; if it has a drain plug on the bottom use it. If not you will need to remove the tank and sit it on one side.

 

[EA90_S]

Why dont u try putting back the old fuel pump back in beacuse u said that u put 10 bucks petrol in and drove it around for abit then put in the Mizer fuel pump in then it stuffed up so maybe that could be the probelem.

 

[Tragilgas]

Thanks for the reply Aussiblue

Yep we've replaced the inline fuel filter (that's the one sort of near the rear left wheel isn't it?) and replaced the fuel pump.

 

[Tragilgas]

Why dont u try putting back the old fuel pump back in beacuse u said that u put 10 bucks petrol in and drove it around for abit then put in the Mizer fuel pump in then it stuffed up so maybe that could be the probelem.

The old fuel pump is completely dead and long gone in the trash I had already siphoned out that $10 worth of petrol before putting the new pump in... the only reason I put that petrol in was to try and pick up a bit of crap that might have been in the tank.

Aussiblue, I had a good look in the tank after siphoning out the $10 worth of petrol and it seemed pretty clean, i know what you mean about the gunk at the bottom but couldn't see any and pretty sure if there was some it wouldn't have been picked up by the fuel pump.

 

[Aussiblue]

Change the filter; it will need it.

 

[Aussiblue]

At least pull of the tank side hose on the filter and see how much crap comes out.

 

[svo347]

Being duel fuel check out the Fuel cutoff solenoid

 

[Tragilgas]

At least pull of the tank side hose on the filter and see how much crap comes out.

We did replace the fuel filter at the same time as replacing fuel pump, but yeah I'll take the hose off and see if there's any crap in the new one that it might have sucked from the tank.

Being duel fuel check out the Fuel cutoff solenoid

Is it something I'd be able to check out myself, or would I have to get a mechanic to look at it (not very experienced with cars myself). What exactly does the fuel cutoff solenoid do?

Thanks.

 

[svo347]

Basically shuts the fuel off when you switch over to gas

 

[Noeline]

Having been a gas mech for many years you've taken on a job we even hate,youve neglected to think about the fuel lines being blocked with the same crap you found in the tank. Also their are no petrol solenoids on a fuel injected car, the injectors are shut down normally in the r/h kick panel next to the ecu using two relays and yes the injectors will have to be removed and cleaned professionally as the spray pattern is crutial. next thing is are you getting power to trip the relays when you crank the car on petrol. like i said we used to hate this job
tony

 

[Aussiblue]

Also check the two way valve in the fuel cap hasn't failed; if air can't enter the tank the pump will not be able to suck fuel out; does it run with the cap off?

 

[RaceCraft]

climb underneath and undo and drop the fuel lines into a bucket..Cranking the car on ULP it will either fill the bucket or not.. You can then eliminate the tank, pump, filter and lines from being an issue if your getting a good flow... and it still wont run and you know you are getting fuel to the rail i'd be looking at the injectors..
If for some reason you are getting no flow i'd be looking at an electrical modification

On a side note: is it factory gas? If it is (some aftermarket ones too) actually start on ULP and flick to over LPG when the RPM is above 1000.. If for whatever reason the fuel system stopped working the taxi driver would of had to hold the toggle button in to get a constant green LED ( dedicated LPG start).. So chances are that when the pump died he got it changed at the ECU to start and stop on LPG only.. I can't remember the exact wire you splice/cut but its a 2 min job that most taxi mechanics would have known how to do.. Maybe have a look at the ECU for a cut wire?

 

[turbotrana]

What you will find is that the whole fuel rail is stuffed due yo the petrol being cooked in there and leaving its residues over the years. The injectors will be stuffed and you really need to change everthing that delivers fuel around the engine bay, cause it will just have the crusts of baked fuel remnants. The rest of the fuel system that did not get the engine heat should be OK. Dont even bother to try and clean the fuel rail and injectors, its not really worth while. In these engines the seats on the cylinder head are usually really recessed and theres also alot of crap gas remnants in the top of the cylinder/piston area. In my opinion although gas is cheaper it really stuffs your engine. People say it keeps the oil clean and the engine lasts heaps longer but in my opinion its a falacy. They last heap less than a well serviced petrol engine

 

[Noeline]

I agree with both replys above now why dont you ask a simple question like how to fix the gas so it doesn't backfire believe its much cheaper than what you've asked. in 99% of cases it came back to plugs, leads & coil pak which is under the intake manifold. always found NGK plugs one range colder than std and eagle leads at least 9mm did the trick and thats assuming the mixtures arnt to lean as this will cause backfires as well. You will be running whats known as a closed loop system which should tune itself however with an ex taxi there are no guarantees on anything. it would be easier if you knew what brand the gas system is as they all have weaknesses. Tony

 

[Tragilgas]

Thanks for the replies.

I picked up a set of 2nd hand injectors and put them in with a mate but as expected it still won't go on petrol. The old injectors were so clogged up, on one of them the tip was falling apart, so they definitely needed replacing anyway.

Also check the two way valve in the fuel cap hasn't failed; if air can't enter the tank the pump will not be able to suck fuel out; does it run with the cap off?

Just tried it with the cap off last night and it didn't make a difference.

On a side note: is it factory gas? If it is (some aftermarket ones too) actually start on ULP and flick to over LPG when the RPM is above 1000.. If for whatever reason the fuel system stopped working the taxi driver would of had to hold the toggle button in to get a constant green LED ( dedicated LPG start).. So chances are that when the pump died he got it changed at the ECU to start and stop on LPG only.. I can't remember the exact wire you splice/cut but its a 2 min job that most taxi mechanics would have known how to do.. Maybe have a look at the ECU for a cut wire?

Nah it's an aftermarket Impco system, and instead of a toggle button it has a 3 position switch: the right pos. is Gas (Green LED), left is petrol (Orange LED) and center is neither, the car just cuts out in that position. So it's been doing dedicated LPG starts for a few years.

I do reckon they could have disconnected some wiring to do with the petrol when it died, so at the moment I'm having it checked by my autoelectrician. If he doesn't find anything wrong I'll do as you said and drop the fuel lines in a bucket and see if it flows. I'll let ya know.

Thanks again.