[SlowE92]

Anyone have a DIY on how to flush out the fuel system? Small back story, put in bad gas and had to flush out the fuel system as the car was cranking and not turning over. Drained the gas tank and car still will not turn over. Took off fuel rail and had mixture of IA alcohol in it and so I cleaned it out and all connections, including the injectors. Car still cranks and won't start. New plugs and coils and battery, starter, alternator. Plugs get spark when I ground them, Battery doesn't dip below 11V when cranking. LPFP is at 75. Is there fuel in the lines still that is causing this issue? If anyone knows how to flush out the fuel system completely. Also do not have any codes to report.

[eljay]

Can you disconnect the fuel line, run it to a bucket and activate the fuel pump to get all the fuel out, then refill tank with fresh fuel?

I'm just guessing as I haven't tried this myself, but that's what I'd try in your case.

[tcphoto]

Just to add to eljay, a new fuel filter would be a must for me.

[lordnikon]

There is no external fuel filter in the e90 gasoline/petrol models. It's integrated in the fuel tank.

[SlowE92]

Originally Posted by eljay

Can you disconnect the fuel line, run it to a bucket and activate the fuel pump to get all the fuel out, then refill tank with fresh fuel?

I'm just guessing as I haven't tried this myself, but that's what I'd try in your case.

How would I activate the pump? I drained the tank completely and refilled with fresh fuel. When I disconnect the fuel rail connection, it still has that weird alcohol smell.

[lowrydr310]

Originally Posted by SlowE92

How would I activate the pump? I drained the tank completely and refilled with fresh fuel. When I disconnect the fuel rail connection, it still has that weird alcohol smell.

Do you have INPA? You can do component activation and command the fuel pump to turn on.

You have a N54 right? When I replaced only two injectors, the first time starting the car! ok a long time to crank and then it took about 30 seconds for the engine to smooth out. If there's bad fuel in all those injectors, you should try to get it out of there.

[SlowE92]

Originally Posted by lowrydr310

Do you have INPA? You can do component activation and command the fuel pump to turn on.

You have a N54 right? When I replaced only two injectors, the first time starting the car! ok a long time to crank and then it took about 30 seconds for the engine to smooth out. If there's bad fuel in all those injectors, you should try to get it out of there.

I don't have INPA. Yeah I'm 85% sure I flooded the engine from all the cranking. Pulled the plugs and they're all soaked so I don't know how fked I am at the moment. Last night when I disconnected the fuel pump it ALMOST turned over, then it just did the same crank no start. I left it disconnected and tried pumping the fuel out. Just at a loss at the moment, don't know how to flush the fuel out of the cylinders and Dr. Google hasn't been very helpful.

[SlowE92]

Originally Posted by Efthreeoh

I'd try starting it with ether (starting fluid). It should run long enough to clear out the old fuel in the fuel lines. Repeat until the engine runs on its own.

Should I spray it into the air intake? Or remove the vacuum hose on the TB and spray directly into it. If I let the car crank for longer than 10 seconds it slowly dies out and then I get codes that come up when it sputters out and the battery is dead.

[lowrydr310]

As long as your can of starting fluid has a straw, the vacuum nipple on the throttle body would be a great place to spray it.

What was the fuel contaminated with? If it was pure water, you might want to remove all plugs and crank the engine over to clear the cylinders out.

[SlowE92]

Originally Posted by lowrydr310

As long as your can of starting fluid has a straw, the vacuum nipple on the throttle body would be a great place to spray it.

What was the fuel contaminated with? If it was pure water, you might want to remove all plugs and crank the engine over to clear the cylinders out.

I bought some gallon jugs of E98 from someone and it reeked of IA alcohol. And my dumb*** put it in without checking first lol. Shortly afterwards the car sputtered and died on me and would just crank and not start. I removed the fuel pump connection and cranked it to push the fuel out. I didn't know I had to remove the plugs first, just the fuel pump connection but thank you I'll try that as well.

[Tambohamilton]

Originally Posted by SlowE92

Should I spray it into the air intake? Or remove the vacuum hose on the TB and spray directly into it. If I let the car crank for longer than 10 seconds it slowly dies out and then I get codes that come up when it sputters out and the battery is dead.

Cranking for 10s drains the battery? Your battery is done, or needs to be fully charged.

Also, 'turning over' = 'cranking'.

[SlowE92]

Originally Posted by Tambohamilton

Cranking for 10s drains the battery? Your battery is done, or needs to be fully charged.

Also, 'turning over' = 'cranking'.

Car has sat for a long time while trying to figure this issue out, has no charge left. Bought the battery a couple months ago.

[Tambohamilton]

It'll take a long crank to pressurise an empty fuel rail, so you best get a good charger! Or start on sleazy-start, as efthreeoh suggests...

[SlowE92]

Car starts with the starting fluid. But dies immediately, even with my foot on the accelerator or feathering it.

[Tambohamilton]

Need to run/crank it for a while to bleed the fuel system. My diesel took probably 4x 30s cranks to fire up - would expect similar for you. I also cracked off an injector fitting for the first couple of cranks, to bleed the air faster...you do that at your own risk though!

Have you checked for codes recently?

[SlowE92]

Originally Posted by Tambohamilton

Need to run/crank it for a while to bleed the fuel system. My diesel took probably 4x 30s cranks to fire up - would expect similar for you. I also cracked off an injector fitting for the first couple of cranks, to bleed the air faster...you do that at your own risk though!

Have you checked for codes recently?

When the car quits cranking and loses all charge it throws a plethora of codes, "inlet gap loss" "HTML" I'm not at the car at the moment but they're mostly sensor codes in regards to low voltage. With the starting fluid it starts right up but immediately dies and does not throw any codes.

[Tambohamilton]

Yeah low voltage will always do that. Reassuring that there are no codes normally though

[SlowE92]

Originally Posted by Efthreeoh

Just keep spraying fluid into the intake until the fuel in the line clears.

I've gone through a quarter can and the progress I've made is it will idle for a second or two longer, then dies.

[Efthreeoh]

Originally Posted by SlowE92

I've gone through a quarter can and the progress I've made is it will idle for a second or two longer, then dies.

It sounds like the engine is getting flooded if the plugs remain wet.

[augustus maximus]

Pull the back seat and lift out the fuel pump. Then use some kind of pump to drain the tank. Also clear the fuel line to the engine by pulling the connection at the injector rail and let it run out when you turn on the ignition. Stop spraying starter fluid into the intake.

[Tambohamilton]

Originally Posted by augustus maximus

Pull the back seat and lift out the fuel pump. Then use some kind of pump to drain the tank. Also clear the fuel line to the engine by pulling the connection at the injector rail and let it run out when you turn on the ignition. Stop spraying starter fluid into the intake.

[lowrydr310]

Originally Posted by augustus maximus

Pull the back seat and lift out the fuel pump. Then use some kind of pump to drain the tank. Also clear the fuel line to the engine by pulling the connection at the injector rail and let it run out when you turn on the ignition. Stop spraying starter fluid into the intake.

Didn't you read the first post? He already drained the tank and was looking for tips to clear the fuel line and rail. On the N54 you can't just 'pull the connection at the injector rail' because there's not a quick connect between the HPFP and injectors.


Starting fluid *can* work if there was a little contaminated fuel left in the line, but if it hasn't worked yet and gotten the car started by now, then yeah I'd go back to making sure the fuel line between the tank and the HPFP inlet free and clear, full of fresh uncontaminated gasoline.

- Disconnect the electrical connector that supplies power to the fuel pump (so it doesn't prime while the line is disconnected)
- Disconnect the fuel line where it connects to the metal fuel inlet to the HPFP (under your intake manifold; need to remove charge pipe and throttle body to get access)
- Get a helper to hold that fuel line in a bucket with a rag over it, take all precautions for having gasoline spraying, since there will be 70PSI of fuel coming out of there soon
- Plug in the power connector to the fuel pump
- Use INPA to get to the DME menu (MSD80) -> F6 Component Triggering -> F1 Actuator Activation 1 -> F5 Electrical Fuel Pump EKP - > F1 Fuel Pump On

This will run the fuel pump, I've done it before and don't remember how long maybe 10 seconds or so. With the fuel line disconnected at the hard inlet to the HPFP this should clear all the bad fuel out. You might still have a little residual bad fuel in the HPFP and in the rail and injectors, but much less than before. Do that first and make sure you have clean fuel at the HPFP inlet. Then some extended cranking should get you running; again make sure the battery is healthy and charged.