Fuel pooling in intake (causing extremely long cranks)

[AncientTV]

Continuing the saga of my recently acquired, heavily neglected 318i, I now need to figure out why fuel is pooling up in my air intake boot. When it's empty, the car starts first crank, but apparently as the engine runs, fuel pools up in the intake. I've replaced the FPR as per suggestions in other threads (last one was busted, but I know this one is good. There's no fuel in the vacuum line.), but it still has the same problem. After shutting the car off, I have to drain the fuel from the intake (a huge amount usually, enough that it almost overflows when I remove the boot) before it'll start again.

I'm checking the fuel return lines today to make sure they aren't clogged, and I'm wondering if there's anything else I can check besides that.

Thanks!

[BimmerTim]

Injectors. One or more of the needles probably aren't seating and is leaking a fair amount.

[AncientTV]

That's what it's looking like. I noticed that fuel is dripping in from the intake manifold. Is this a replace-the-part type repair, or is there some way I can fix itk?

[BimmerTim]

You could have the injectors cleaned, balanced and rebuilt. I'm not sure on the cost of that vs. new injectors.

[AncientTV]

This is a long shot, but could it possibly be bad connections on the injectors? All the plugs are extremely loose and can pulled off by just touching them.

Excuse my ignorance, I come from carbed motorcycles.

[u3b3rg33k]

The only time i've seen fuel pooling in the intake boot on an M20 was when the FPR failed (due to a clogged return line), and it was spurting fuel out of the FPR vac line, into the manifold, running down the boot and out the airbox weep hole.

There's no way for injectors to cause fuel pooling in the M20 intake (not that I can think of right now anyways), they aim down into the head, it would have to pool on the backs of the valves.

[Jaxx_]

There's no way for injectors to cause fuel pooling in the M20 intake (not that I can think of right now anyways), they aim down into the head, it would have to pool on the backs of the valves.

all fuel injection designs that I've seen are like that. they are usually aimed straight into the intake valve for best atomization

[AncientTV]

The only time i've seen fuel pooling in the intake boot on an M20 was when the FPR failed (due to a clogged return line), and it was spurting fuel out of the FPR vac line, into the manifold, running down the boot and out the airbox weep hole.

There's no way for injectors to cause fuel pooling in the M20 intake (not that I can think of right now anyways), they aim down into the head, it would have to pool on the backs of the valves.

I personally don't know if they're much different, but I'm posting about the M10.

edit: A little more info: I have to pump the gas pedal on starts, or the car literally takes a minute or more to crank. Also, I did a starvation test. Took out the pump relay, so the only fuel in the system was in the rail; the car started perfectly on the first crank.

[SoopaGhetto]

cold start injector? you try disconnecting that injector and seeing if that made a change? The only way i can see pooling at the elbow is from this injector not closing properly and just spraying fuel constantly; and since the throttle is directly under the manifold blah blah blah.

[AncientTV]

cold start injector? you try disconnecting that injector and seeing if that made a change? The only way i can see pooling at the elbow is from this injector not closing properly and just spraying fuel constantly; and since the throttle is directly under the manifold blah blah blah.

I doubt this was the source of the problem, but disconnecting the CSI did indeed help a fair amount. The car cranks in 2-3 seconds instead of 10-15 now. I'm assuming it's because there's just less gas being vomitted into the intake now.

Thanks for the suggestion!

[Jaxx_]

I would test your injectors to see if any of them are stuck open.

[Jean]

is this an m10 car? test the cold start injection circuit, pretty sure bentley has instructions on when it should be on/off etc.

[bmwm42]

Cold start injector was my thought in this one