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tek-nic

New Member in CO with Fuel problems, carbs, carbs, carbs.

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Hey everyone - thanks for reading, first of all.

I recently purchased a 1970 BMW 2002, basically stock.

The car had sat for a long time in the PO's garage, and I have been bringing her back to life.

I drove the car to work today, and while I was at lunch, it decided to die.

Driving along, the motor started to sputter, and then died. I tried restarting with a lot of choke, and it wouldn't fire back up.

It has the mechanical fuel pump, a new filter, and a full tank. Single barrel carb.

The fuel filter is not as full as it usually is - this is the only thing I have been able to notice. I had something similar happen to me the other day... where the car died, and fuel delivery was the issue. I determined that the cause was vacuum in the fuel tank. When I loosened the gas cap, I had to lightly pry it off because vacuum was holding it on. When I got it off, air rushed in, and I watched the filter (clear plastic type, sitting in line between the tank and the pump) fill back up. Turned the key, and she fired right up.

So... anyway I thought that this was the same problem. I popped the gas cap, there was a small vacuum present. The fuel filter did not fill back up like the previous time.

I tried turning the motor over a bit to see if the pump would fill the filter back up, and get everything right... but it did not.

Please, I have searched the forum, and have not found anything that seems to be the culprit. I am new to 2002's... so it may be simple. My only thought is that the tank is either clogged, which I think is unlikely, or maybe the pickup is messed up? Is the tank supposed to be pressurized, or vacuum, or vented? My gas cap says it is non vented.

Please help me out - I really dont want to flat tow this thing across town tonight. I am hoping to find a quick fix to apply in the parking lot tonight after work.

Thanks everyone, and sorry to make my first post so damn needy.

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I don't think it is an issue inside the carb... mostly because the fuel filter appears nearly empty... and it is usually 90% full. Like the fuel isn't getting to the carb at all.

The carb is slated to be rebuilt soon, but I don't think that's what has me stranded at the moment.

note: not arguing, just trying to provide useful information back to the forum in the hopes of narrowing down where my problem is.

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Totally normal for the fuel filter not to be full - it's a filter, not a reservoir.

If it won't idle, I'd be suspicious of a blocked idle jet - all I'm saying!

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I understand. I didn't try for too long, but it wasn't starting at all once it died... this wasn't an idle, but a complete lack of running.

I will look at the carb for sure once I get it home.

The thing that confuses me is the filter. When the car was running well, the fuel filter is generally about 60% full at least. Right now, it is not even close to that 'normal' level that I have seen... it is much more empty.

What would cause this?

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I understand. I didn't try for too long, but it wasn't starting at all once it died... this wasn't an idle, but a complete lack of running.

I will look at the carb for sure once I get it home.

The thing that confuses me is the filter. When the car was running well, the fuel filter is generally about 60% full at least. Right now, it is not even close to that 'normal' level that I have seen... it is much more empty.

What would cause this?

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Have you pulled the fuel sender out the gas tank to check the filter/screen at the bottom? Could be clogged from sitting with old gas for years.

I'd get a new o-ring/gasket for the sender if you do remove it, and install it soon - keeps the gas smell from wafting out of the tank-sender junction.

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If it sat for a long time my guess is lots of rust inside the tank, this has probably clogged the pick up screen inside the tank. The fix is to remove the fuel level sender/pickup from the tank and clean the screen on the bottom of the pickup. If it is clogged you will need to drain the tank and have it cleaned or this will continue to happen, cleaning it should get you home.

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BTDT, years ago on the tii.

Cheers,

If it sat for a long time my guess is lots of rust inside the tank, this has probably clogged the pick up screen inside the tank. The fix is to remove the fuel level sender/pickup from the tank and clean the screen on the bottom of the pickup. If it is clogged you will need to drain the tank and have it cleaned or this will continue to happen, cleaning it should get you home.

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How hard is it to pull the sender? I haven't even looked into yet...

I'm not shy about taking it apart, and spraying some carb cleaner or something on the screen to clear it off. It does sound like this could be my problem.

If anyone has a way to give me an idea of what to expect when pulling this out... please don't hesitate.

Also - if I want to pull it out, and clean it, then put it back in all in the parking lot... will it be okay to reuse the seal?

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How hard is it to pull the sender? Several nuts, wiring connections, and hose clamps

If anyone has a way to give me an idea of what to expect when pulling this out... please don't hesitate. Gas will pour from the sender, so have a bucket, or move fast to get it out of the trunk!

Also - if I want to pull it out, and clean it, then put it back in all in the parking lot... will it be okay to reuse the seal? Yes

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You should be able to remove it, clean the sender, and put it back in place. Whether it will seal again is questionable, as the O-ring that seals the sender to the tank may die when you remove the sender.

Before attempting to remove the sender, disconnect it from power, and clean the surrounding area. Get a cloth, or a roll of paper towels handy to clean up the gas that you'll undoubtedly spill when you lift the sender from the tank. The sender is held in place by tabs, and can be removed by first twisting the sender free of the tabs, and then lifting the sender out of the tank. It is often necessary to tap on the sender tangentially to initiate the rotation. Once it is free of the tabs, lift it SLOWLY until it's nearly out of the tank, then hold it in place while gas pisses out of the small hole in the side of the sender column. If you simply lift it out quickly, it'll piss gas all over the trunk of your car, and possibly on you.

Be careful cleaning the screen on the bottom of the sender. It you don't find a screen, it probably fell off, and is in the tank. You could use some cheesecloth and a zip tie to replace the screen if necessary. However, if the screen is missing, there's probably gunk in the sender that needs to be cleaned out. If the screen is in place, you can carefully pry it loose and clean it with whatever--a toothbrush, your finger, compressed air, etc. You're trying to get home, not put it on the podium at Le Mans.

Best of luck!

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I had my one barrel '02 die when I was coming off the freeway once. It turned out to be a clogged idle jet. It would run if i kept the throttle half way down and die if I lifted off too far.

I agree with the others that you might have sludge in your tank. An easy way to get home might be to blow into the feed hose to loosen the gunk in the tank. Light pressure only (1-2 psi) Then when you are home, remove the sender and clean it. (had this problem on an old 510 of mine...took me forever to find the problem)

Early tanks have a fuel drain plug too. Makes draining fuel easier.

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Thanks for the tip - I will give this a try too.

I'm going to go try and get it running in a couple hours after I get off work.

I'll post the results here - and thanks again everyone -this forum is going to become my new favorite!

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Should there be vacuum in a 1970 tank? Were they vented to air, or part of evac system?

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