Cleaning carbs and fuel pumps

7173bmw

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Is there a rebuild kit available for the Zenith carbs for my 73 3.0cs? Is there a rebuild kit for the manual fuel pumps? Parts cleaner safe? I've started working on one of the cars, the engine has been sitting so I would like to remove, soak, clean and rebuild. Outside of dropping and flushing the gas tank, are there any other steps I'm overlooking? (fluids, plugs, wires, dist. cap, rotor, oil filter)

Thanks,

ND
 
You can get the rebuild kits here:

http://classicgarage.com/bmwba32528ma.html

or at Mesa Performance. Get the major kit with accell pump gaskets etc. although quality and fit aren't great. When you assemble and tighten the 4 bolts from the bottom venturi plate wait 24 hours to retighten before putting back onto manifolds because the gaskets will compress. I repeated this twice.

Depends on what fuel pump you have, some are not rebuildable, post a pic here so we can see.

Flush gas tank, check for rust/scale, if nasty use POR-15 gas tank sealer.

Replace fuel filter

Here is a post from when I rebuilt mine:

http://www.e9coupe.com/forum/showthread.php?t=7120

also search here for "Zenith" and you'll find other rebuild threads.

Regarding the engine stuff the others here will better advise then me.
 
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Thanks Steve! Those links are awesome! Here are the pics of my fuel pump. It looks as though it does come apart and has some type of gasket. The fuel pump in the same location from my '71 2800 looks quite a bit different, but still the same. Know what I mean?

Thanks,

ND
 

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For that pump it loks like the rebuild kit may still be available, if it's in really bad shape you may want to consider replacement. Looks like part #13311255184 and available here:

http://www.penskeparts.com/DiagramsMain.aspx?vid=47811&rnd=06222010

or here:

http://www.bmwmobiletradition-onlin...el=3435&mospid=47811&btnr=13_0726&hg=13&fg=10

Last part on the list. I like Penske's service.

Or scan eBay for 3.0cs fuel pump or Google the carb #13311260677 and see what comes up. The non-rebuildable pump version will probably fit too if you find that one.

Replace all those crusty fuel lines and clamp each fitting at carbs, pump, filter, and where it joins the metal tube at the firewall, it looks like a fire waiting to happen!
 
fire in the hole... after sitting

I would start with making sure the motor turns easily then cleaning down the motor/ engine compartment. It's a much more pleasant experience and things are more easily seen when you drop something.

I would soak down with penetrant the carbs, manifold nuts, etc. at least twice. ( Don't want any studs breaking off.)

I would carefully remove the plugs and document what they look like. Black fluffy deposits, oily, nice and tan which indicates how healthy it is or was. I spray some oil down the cylinders just for grins.

I would pull the radiator and back flush it 2 or three times. Squeeze all the hoses- crunchy? Replace.

I would look over each part of the ignition, points etc. and if everything looked good, cleaned, reset, and static time the ignition.

Fuel pump- can be operated by hand on the bench. if it pumps, it's good for now.

BEFORE stripping the carbs, note the adjustments and write them down. Don't touch the throttle screw adjustment. You're just cleaning and making sure the jets, float, etc. work. If there's "white rust" in the float chamber- dremel with a wire brush. If the throttle plates are stuck- penetrant wiggle, repeat.eventually they all break loose. DOn't take the plates off the shaft. You just want to make them operational.

Gas-Steve talked about the tank already.

Before starting- remove the coil wire and crank it to get some oil moving first. if the oil looks decent don't change it just yet. A new filter would have to be filled and you want oil pressure fast.

Gas II- pour about 1/4 of a paint can top down the carb.

Put the wire back on the coil and fire it up. You just want it to run for a minute or less so you can look around and make sure nothing's leaking, smoking, etc. All ok? Fire it up and watch the temperature to make sure nothing gets too hot. ( T-stat-)

Once you've satisfied yourself it can run good or bad, then you can go back and tune/ replace parts, etc.


Carbs and your picture-

1. Don't try to take the chokes off by the hoses. Cut the hose and slit it. Those little nipples can get brittle so be careful. I usually remove the choke by the three screws on the ring. The bolt on the end- there's a rubber o ring and a copper washer below. Hardware store. But be carefull when taking it off.

2. You have some emission controls still on the car. Time to decide what you'e going to junk and plug since they're not available.

3. Everyone decides to disaassemble the carbs more than necessary. It's better to clean and check each function first. If the float valve works don't take it apart for example. Save your gaskets as you take them off for comparison.

Read the other posts, and ask questions.

Good luck.
 
Thanks Guys!

61Porsche...awesome breakdown!

There was a clicking when I turned the key. from my experience with my 911, I assumed it was the fuel pump. then all of a sudden, it has stopped. Any ideas what happened? Also, how should I test the fuel pump once I remove it from the motor?

The motor turns easily(thankfully!). Outside of the carb cleaner for the carbs, what should I use to soak down the rest of the motor; PB Blaster, carb cleaner, something else?

What emissions are on that I can remove? I'm in New York so all I need is to pass safety inspection because of the year of the cars.

Thanks,

ND
 
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Starting, etc.

The clicking, then nothing is the starter. Disconnect the battery ( check the volts to make sure it's got a good charge), clean and tighten the connections on the starter being careful with the small wires. SOmetimes it's just the solenoid- you can temp. jump it to see what the starter is doing.

The other possibility of the nothing conditon is the ignition switch- under the dash, inside the column cover , is the switch, push hard on the back and turn the key- if all of a sudden it works then it just is loose in it's can which is staked on. Get the appropriate size punch or small screwdriver and restake is usually what is needed. If that works- take the time to gently loosen the small set screw holding it in and restake the other side and save yourself the money for a new switch.

I usually suggest that if you take the rear manifold off to get to the carb, pull the starter and have it checked at the local parts house or test it yourself. It's hard to get to, so if it's been on there for some time just replace with a rebuilt which should be cheap. But I understand costs and budgets too so you make that call.

Cleaning the engine- a good degreaser and some elbow grease.

The emissions- look below the carbs/ manifold for tubes and an egr valves. There are electrical relays on the firewall that run different vacumn functions. Does your distibuter vacumn can have two hoses? One is advance and if you have it is a retard that works off another solenoid.

Post some more pictures after you clean things up a bit.

Fuel pump- it's a pump- so it will blow some air you can feel. Or you can gently remove the screws and examine the rubber diaphram. Or hook up some short hose- a small container of gas, operate, and see if it gas comes out. Be sure to blow out the fuel line back to the tank after you take the hose off at the tank and cover it with a rag. ( so you can see any gunk)

Good luck- get the starter working.
 
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+1 on replacing the starter (if you find that it is the culprit per Jerry's advice) when you have the manifolds off for the rebuild (get those gaskets too, they're cheap and a source of potential air leaks), it's cheap insurance (I got one for $60 rebuilt) and you will never want to go back and get to the starter again - its very tight in there.

Don't use carb cleaner on anything unless you want to ruin the paint. Simple Green cleans well.
 
Tested the fuel pump and...nada! Took it apart and saw a lot of cracking on the outer rim of the diaphram. No holes but from what I've read, it doesn't take much. Blew out the line to the gas tank and that was fine. New hoses and clamps and I'm going to take a fuel pump off of one of my other motors tomorrow and see if I'm closer to hearing her sing!

ND
 
And if you need a new starter get the smaller permanent magnet starter such as the e30 M3 S14 type. Bosch SR-440X (some still labeled as SR-71X but you might get an older big one) fits well, shorter and lighter.
 
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