Fuel Pump Working, But won't start

[Deutscher]

Hi all,
just came back from holidays to find my car won't work. My dad drove it once a week or so but one day it wouldn't start anymore. Had RAC come out and look. No fuel was going to the engine, RAC guy got a sprayer and sprayed directly into the engine from where the air filter connects to the engine. The car started up fine but died cause he only put a little amount of fuel in. So he said it's a fuel problem, he checked the fuel pump fuse and it's working fine. So he couldn't do anything and said take it to a mechanic.

When I got home I had a scope around, checked all fuses etc, quick exam of fuel lines (nothing I could see easily, need to do better check though), and turned on the ignition but couldn't hear the fuel pump turn on, so disconnected the fuel filter line and tried turning the car on but no fuel came out...only dribbles ... kinda told us the fuel pump is seized. So today my mates and I replaced the fuel pump and filter and put it all together, tested the car and wouldn't start still.

What's the next step? Sparks are working, ignition working, fuses working, fuel pump working. My mate does quite a lot of work on commodores and it's got him stumped... could it be a fuel regulator or something? o and the return line returns fuel. Tomorow i'm going to check the lines going directly to the fuel rail... I just don't know where that is yet, to see if fuel comes out of there or not, cause if there's fuel coming from that I definately don't know.

Anyone got suggestions?

O.. taking out the fuel pump was a mission!! I've got the tow bar on my car still, so i've got the bars that go under the tank etc, we undid the two bolts that connect up to the body (towards front of car, past fuel tank etc (near diff)), unscrewed the 4 bolts that connect up on the end of the boot (can undo from inside boot floor) and also unscrewed the two bolts that are in the boot but on the end panel (sorry, cant explain it better), we think it's all the screws and it comes down like 1cm from the bolts but won't budge more. Do I need to take of the rear bumper? is there something caught there?

Stupid towbar!

[delcowizzid]

sounds like the injectors arnt pulsing maybe a keyhead/security issue

[Chirpstr]

Hey, I would try the easiest by swapping the fuel pump and maybe the EFI relays over with a say a high beam or low beam (one you know is 100%) and see how you go from there. I suppose the new fuel pump dribbles as well? If the relays are ok and don't seem to do nothing then it has to be within the pickup of the pump.

As to the tow bar, I think you'll have to remove the rear bumper because it bolts to the rear bumper reo or near there If I remember.

[VrWagz1]

ill put 2 bob on injector pulse too. Has the little red light stopped blinking in the car when ya go to start. If not you got imobiliser issues. But besides that efi realy fuses ect.

[Deutscher]

Meh, Stupid car!

I go on holidays and when I get back it aint work!
I checked the fuses (not relays), checked the sparks. Immobiliser shouldn't be an issue because when I squirted fuel in, it started fine and ran after switching to gas.

I put a new fuel pump in and changed the fuel filter. Fuel pump dribbling? no, haven't seen any leaks etc. How you mean dribble and from where?

Injectors not pulsating? Sorry I'm pretty far away from calling myself a car mechanic! How does gas get 'injected' into the engine? doesn't it go through the injectors aswell? Oh and not all the injectors could screw up at once could they?

[woteva]

How does gas get 'injected' into the engine? doesn't it go through the injectors aswell?

The gas does not go through the injectors.

Oh and not all the injectors could screw up at once could they?

If there is no pulse, the injectors will not fire.

Is the new fuel pump working ok ?? Pull off a line and check it out.

Also, when on gas, the power to the fuel pump may be cut to stop the pump running when not needed.

[Deutscher]

We connected it and when you turn the ignition, you hear it working. We've undone the hoses and fuel came out of the lines. Only thing we not sure about is... theres 2 hoses ... normal one and the return one .... if you mix them up does it not work anymore? We can't remember which one was which. There's fuel coming back from the return line so... fuel pump must be working or? I'm guessing theres a blockage in the fuel lines or .. now unfortunately im guessing injectors

When I get home I'll try pulling a fuel line near the engine bay off and see if fuel comes out of it.. to see if the fuel makes it up there. When the fuel pump is running ... how much fuel will come out? like heaps and fast?

What do I have to do if it's the injectors? Is it an easy job? or should I take it to mechanic? I'm a uni student so money is tight, what price would I expect?

[Chirpstr]

Yes it does matter if you mix the fuel hoses up. Maybe try swapping them over and see how you go. When you say fuel is coming back from return line, where abouts on the return line? If there is no fuel reaching the fuel rail then I can't see fuel coming back. Disconnect the incoming line in the engine bay, runs from fire wall then heads towards throttle body and then try cranking it over...it should do strong squirt pulses.

[kopper69]

All 6 injectors failing simultaneously? Not likely.

You can check for a signal at the injectors using a multimeter or test light on the signal connections on the injector (disconnect the plug off the injector and check for voltage on the pins while a friend trys to start the car).

The CAS (Crank Angle Sensor) supplies the signal to the injectors through the DFI module. If the CAS fails you dont get any signal to the injectors or spark plugs. CAS is a really common fault in the VR/VS, but if youre getting spark its unlikely. If you have spark its going to be a fuel issue.

You need to check the fuel pressure. That will tell you if the fuel pump and regulator are working ok. Check injectors as mentioned previously to find out if injectors are pulsing the fuel. It is important which lines are connected up, so make sure you have them right.

If you have fuel and signal at the injectors you are getting fuel into the cylinders. It would then be likely that you have a flooding issue, which can be caused by a leaking vacuum hose off the fuel pressure regulator. The regulator leaks fuel back into the vacuum line which floods the engine.

[moff_man]

All 6 injectors failing simultaneously? Not likely.

You can check for a signal at the injectors using a multimeter or test light on the signal connections on the injector (disconnect the plug off the injector and check for voltage on the pins while a friend trys to start the car).

The CAS (Crank Angle Sensor) supplies the signal to the injectors through the DFI module. If the CAS fails you dont get any signal to the injectors or spark plugs. CAS is a really common fault in the VR/VS, but if youre getting spark its unlikely. If you have spark its going to be a fuel issue.

You need to check the fuel pressure. That will tell you if the fuel pump and regulator are working ok. Check injectors as mentioned previously to find out if injectors are pulsing the fuel. It is important which lines are connected up, so make sure you have them right.

If you have fuel and signal at the injectors you are getting fuel into the cylinders. It would then be likely that you have a flooding issue, which can be caused by a leaking vacuum hose off the fuel pressure regulator. The regulator leaks fuel back into the vacuum line which floods the engine.

i will agree with this but in saying that the dfi module could be at foult!
the cas has 3 signals 18x 3x and crank shaft referance signal
if you loose the 3x signal whilst the engine is running it will contune to run but will not restart
if you loose the 18x signal whilst running the engine will cut out

also the crank shaft referance signal generated bye the dis (dfi) module if this is not sent to the pcm ecm it will not pulse the injectors

in short i think your ither up for a cas or dfi module or both

and since you can intruduce fuel to the cylenders other than the injectors means its not the cas but more than likley the dfi module.

and since the dfi module is easest to change for testing i would do that first with a known good one.

[Deutscher]

Hi guys,
Just tested some more.
Fuel is going through the lines, through the fuel rail and back out the return line.
Hooked Voltmeter to injector connections.. got 12v reading.
So fuel pump is working.

About this fuel regulator? could it be an issue? I don't know how to test it nor get it out.

According to Kopper, it's not my CAS, because I get spark while running on gas and when directly injecting fuel it starts up with ease. About the fuel pressure, I don't know how to test but when we had the hose off it squirted good.

Ok, how do I check if the engine is flooded? also if it is how I fix it?

To moff_man: The case was, car drove fine got home, next morning tried to start car, wouldn't start. Sorry your post is confusing me, I don't know what the DFI, PCM ECM etc does. I'll read some stuff though. Thanks for the hints.

The only thing I want to ask was that, if the float in the fuel tank isn't correctly placed in the fuel tank (it was a mission to get out and in, so maybe it turned or something you know), could this give false information to the engine not to spark the fuel or something? Cause I have no fuel reading on my fuel gauge (there's not much fuel in there... few litres I suppose) but should be enough to start it.

[Deutscher]

Did I mention, when we squirted fuel into the engine directly, in a few seconds it changed to gas and ran fine.

[VrWagz1]

I still think you got injector issues. If you have spark and it runs on gas then it proves things are mostly fine, your cas is proven your spark is proven. You have fuel at the rails, it can be only one thing and thats the injectors not letting the fuel in. Only other possibility is the pressure reg is fugged and you have no pressure when the injectors open.
No they wont all fail at once, but for some reason the ecu may not be firing them, therefor none will work. Id simply pull a bank out and crank the car and see if fuel squirts out of them, it will atleast eliminate or confirm the problem

[Deutscher]

I still think you got injector issues. If you have spark and it runs on gas then it proves things are mostly fine, your cas is proven your spark is proven. You have fuel at the rails, it can be only one thing and thats the injectors not letting the fuel in. Only other possibility is the pressure reg is fugged and you have no pressure when the injectors open.
No they wont all fail at once, but for some reason the ecu may not be firing them, therefor none will work. Id simply pull a bank out and crank the car and see if fuel squirts out of them, it will atleast eliminate or confirm the problem

Pull a bank out? ... whats that mean? is the injector easy to get out? never taken one out before.

Just learnt that DFI is direct fuel injected. It's under the coil packs, easy to replace .. not that cheap new though. Thought my car was EFI though? heh .. confusing.

[VrWagz1]

im not sure how you do it on the v6's, but basically the injectors are mounted on the fuel rail on each side. You just gotta have a look around and see how it all comes out.

Dont buy a new one unless you really want too. Its way cheaper to buy bits from wreckers. Though you always run the risk of buying a dud too. But in the end i think you end up way in front.

[Deutscher]

im not sure how you do it on the v6's, but basically the injectors are mounted on the fuel rail on each side. You just gotta have a look around and see how it all comes out.

Dont buy a new one unless you really want too. Its way cheaper to buy bits from wreckers. Though you always run the risk of buying a dud too. But in the end i think you end up way in front.

Just figured out my brother has a VT commodore, they have the same DFI module don't they? I'll ask if I can borrow his XD (just for testing of course )

[VrWagz1]

Perfect. Thats the way to do it if ya know someone with the same engine in their car.

[Growler88]

how long was the car sitting? could stale fuel be a part of the cause?

[Deutscher]

Slowly getting there. Just need to keep eliminating possibilities.
But hey this is an experience ... I've learnt more in the past couple days than the 2 years owning it!

[Deutscher]

Hope it's not my CAS, because that seems hard to get off and exchanged.
I'm going to check the DFI and Coil packs tomorow.

My father who checked the fuel lines when I turned the key said it was enough pressure. He tried to hold the hose end closed and said there's enough pressure. Haven't physically tested it using a pressure gauge (cause don't have one).

[VrWagz1]

coil packs should be fine as it has spark.

[kopper69]

The DFI module is the plate below the coil packs. It is about 1cm thick. Best of getting one from the wreckers as you will pick it up fairly cheap. Make sure the connector on the end is nice and tight. Maybe take it off (theres a bolt holding it on) and give it a clean with contact cleaner.

To check the regulator. Off the regulator there is the fuel line and a vacuum line. The vacuum line goes to the throttle body. Disconnect the vacuum line (its just sitting on, no clips or anything) and check for fuel. If there is fuel in there, or a strong smell of fuel, the regulator has failed and is leaking fuel pack into the intake. The fact that you spray fuel in and the car runs suggests that the car isnt flooded though.

At this stage I would be swapping the DFI module or trying to get a gauge to check the fuel pressure. Have you checked for error codes? If the car isnt starting there is a good chance you have an error code which will probably point us in the right direction.

[Deutscher]

Hey guys,
It's not the DFI module, I swapped mine to my brothers and his car started fine. The coil packs are all the same ye? I'll borrow his coil packs and put on mine ... see if it works or not (doubt it, but might aswell try while I'm there). I'll also get some contact cleaner... try that aswell.

What is this vacuum line? It's not the brake vacuum line that goes to the air manifold is it? It doesn't connect to the fuel rail does it? because that's the fuel line. I've had a look in my book but the picture is so crap I can't tell which hose is what... but it looks like it connects to the air intake hose (could be a sensor), but I can't see any hoses that it could be.

[Deutscher]

O yeh, I don't know how this stupid (probably good) error codes work.
What do I have to do? Where to find it?

[Deutscher]

Hmm... guess i'll run down to supercheap and see how much a fuel pressure tester gauge will cost me. I'll need to buy some other stuff there already. Atleast then I can test the fuel pressure.