| usang36 |
Posted
Thursday, Jun 7th 12:21am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 24
Oregon
78 320i, 83 320iS |
Hi, in my fresh 83 320i (US), my fuel distributor has started leaking out of the bottom and fuel is pooling in the intake of the airflow meter. It does this after an hour or so. Cold Start injector is ruled out, as well as injectors. When I discovered this, I replaced the FD with the original one I had and it now leaks also! What could be causing this? The FD is so solid state, the only thing I can think of is that rubber oring that mates the FD to the AFM- although I dont see how it could be the problem. Any ideas would be helpful. WUR leaking into FD? Lambda valve leaking fuel after shutoff into FD?? 
John
83 320iS |
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| docctorwho |
Posted
Thursday, Jun 7th 5:29am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 21
east alton, il
1983 320i/4 m10 e21 |
i seen this on another fourm somewhere!?!? but to no avail...The didn't have an answer either. These guys/gals are great just give them a bit.
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| usang36 |
Posted
Thursday, Jun 7th 7:19am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 25
Oregon
78 320i, 83 320iS |
Yea, that was probably me. I cant get no satisfaction! No one knows about fuel dist. anymore..this is a wider xsection of knowledge though, so hopefully I can get some answers. I dont want to put on a new FD and find that it STILL will leak..
John |
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| Madhatter |
Posted
Thursday, Jun 7th 10:58am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 215
Australia - QLD
E21, E24, E30 |
It can only come from a couple of areas.
1. Running down the side of the FD and into the box. In which case the gasket between the head is probably faulty and allowing fuel to leak out.
2. Running out the bottom of the plunger and into the box. In which case the seal inside on the bottom of the piston has probably had it. That coupled with a bit of wear would allow it to run right out the bottom. |
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| usang36 |
Posted
Thursday, Jun 7th 8:10pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 26
Oregon
78 320i, 83 320iS |
Is this seal replacable? There isnt one on the piston itself; it just slides out with no seal but there is one on the bottom of the FD where it meets the air flow meter...I ordered another of those just to be sure.
John |
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| Madhatter |
Posted
Friday, Jun 8th 10:32am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 216
Australia - QLD
E21, E24, E30 |
No, inside is the piston, thats just the plunger.
You have to pull the head off the distributor and pull it appart. Ive never seen one that didnt go back together without leaking though. The metal gaskets are flimsy. |
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| usang36 |
Posted
Saturday, Jun 9th 12:53am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 27
Oregon
78 320i, 83 320iS |
Thanks, I now see that in the diagram. OK. So I just wrote in to Bimmer Magazines' Q&A and got the go around. The guy says that it 'Cant' be leaking from the bottom of the fuel distributor, there's no fuel there. He thinks its leaking from a fuel line and suggested copper gaskets. Geeze, like I wouldnt know the difference between a leak OUTSIDE vs INSIDE...
But he also mentioned that you cant take these apart or they will leak. I've read that also.. well, I guess I just have two fuel distributor blocks that are leaking due to bad internals..
John |
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| Madhatter |
Posted
Saturday, Jun 9th 6:17am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 217
Australia - QLD
E21, E24, E30 |
You can definately pull appart, and they can definately leak out the bottom.
The piston (they call it a barrel i think) has a rubber o ring on the bottom of it to stop fuel leaking out through the bottom and running down the plunger. If that seal fails, it will allow fuel to go past the bottom and run into the air box (as the plunger comes up from the box).
They dont really have copper gaskets in them, so i dont know if he knows what he is talking about. They have copper washers on top where the banjo fittings are, but the gaskets inside are usually stainless.
What he said about them leaking is largely true. Ive had the same issue with them before. Best solution if it leaks from the body would be to try and get another gasket made up out of sheet metal.
You need to work out 100% where the fuel is coming from though, need to rule out it leaking out the gasket, running down the body of the distributor head and into the air box. |
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| usang36 |
Posted
Saturday, Jun 9th 8:25am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 28
Oregon
78 320i, 83 320iS |
Well he was certain that I had a banjo fitting loose for a fuel line and that was leaking.
Not.
But one other thing he did mention that I didnt see on first read of his post was that water damage will make it leak also. Hmmm. I will check that out later. Today I noticed that the fuel is degrading the gasket that separates the two halves of the air flow meter, and fuel is sweating out of the side. I really dont think I can take one apart to repair it as that metal plate wont go back in right...grrr. I guess I'll go to the bone yard this weekend :0( |
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| Madhatter |
Posted
Saturday, Jun 9th 5:20pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 218
Australia - QLD
E21, E24, E30 |
The gasket between the halves is just a cork one, its only purpose is to seal the air box, not designed to contain fuel pressure.
If you look at the (black) metal head on the distributor you will see a join in the casting (just above the fittings for the WUR). That is the seperation between the chambers, and that is the metal gasket that can leak. That is what you want to make sure isnt leaking.
If it isnt, then you need to look at the bottom and have a look. To get to the barrel you will need to split the head of the fuel distributor, they have some screws in the top that hold it together.
You can pull it appart and replace the o-rings and try putting it back together to see if it leaks. If it leaks, no harm, its already leaking and useless anyway. If it doesnt leak, bonus, saved yourself some money.
Sometimes with thin soft metal gaskets you can heat them at low heat in an oven to soften them up some and return to their shape. It might not work with stainless though, but you could give it a try. |
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| usang36 |
Posted
Sunday, Jun 10th 8:36am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 29
Oregon
78 320i, 83 320iS |
Hmmmm I might just try it. Unless I need a star driver, I dont have that tool to take the distrib. block apart.
On the orings. My local Ace hardware has a bunch of different sizes, but I dont know if they are fuel safe! Ideally, I would love to get ahold of one of the two companys in the US that now remanufacture these and pick thier brains, and pick up proper parts. But alas, they are well hidden. An internet search of thier name reveals resellers, that's it.
I sent another email to the Q and A guy and he mentioned that 'back in the day' when they went looking for used FD's, they would crack a fuel line. If it sprayed, then they would take it. If no pressure, it was probably going to be problematic. He would see that the bosch units, for most cars, would not do well if left with old gas and no flow. One of my three spares has the plunger stuck way up inside from the varnish..not going to use that any time ever..
John
John |
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| usang36 |
Posted
Tuesday, Jun 12th 1:36am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 30
Oregon
78 320i, 83 320iS |
New lead. A local shop suggested that the air flow sensor plate was mis-adjusted too high, and that could be pushing up on the plunger, allowing fuel to leak down the plunger and out. I will test for it later..
John |
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| Madhatter |
Posted
Tuesday, Jun 12th 11:27am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 219
Australia - QLD
E21, E24, E30 |
no matter the position, fuel should not leak out of the fuel distributor at all. |
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| usang36 |
Posted
Tuesday, Jun 12th 9:15pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 32
Oregon
78 320i, 83 320iS |
You are right. But new lead #2:
I leaned out my mixture yesterday, and noticed after sitting for 2 hrs there was no fuel in the intake..hmmm. I will check this morning to see if any collected over night. The idle is a bit rough but everything else seems ok, no pinging..I have a mild cam (276) so it likes it a little rich and that's why it's rough. I will try later today and enrich the mixture a bit and see if it starts leaking again. Find the 'dewpoint' as it were |
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| usang36 |
Posted
Wednesday, Jun 13th 1:47am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 33
Oregon
78 320i, 83 320iS |
Nevermind. I checked and had about 4-6oz fuel pooled in my CAI tube..
-My next ideas: replace with yet another known good FD.
-Switch back to my old WUR. I put the current one on to troubleshoot an issue that occured during warm up, but it didnt help the problem. (air slide).
-Switch out to another air flow meter. At the same time, switch out to another frequency valve.
Lastly, get a reman unit. 
John
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| Madhatter |
Posted
Wednesday, Jun 13th 11:44am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 222
Australia - QLD
E21, E24, E30 |
buy the correct bits to pull it appart, pull it appart, replace o-rings, bolt it back together and see if it works. Any major parts store should be able to supply you with o-rings to suit. |
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| wayfast |
Posted
Wednesday, Jun 13th 8:13pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 9
Belleville, Michigan
81 323i |
when you put it back together, seal it with some of this http://www.acehardware.com/product/index.jsp?productId=1419010
worked for me, but i broke two of the torx screws, by tightening them too much. |
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| usang36 |
Posted
Thursday, Jun 14th 1:16am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 34
Oregon
78 320i, 83 320iS |
Wow, didnt know anyone had the nads to try this. I might as well, nothing to loose and a good experiment. I need to know if the orings ACE hardware sells are fuel safe, and if they arent I wouldnt know where else to look. I will start at the fuel injector service and get ideas from there..
Thanks! JOhn |
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| wayfast |
Posted
Thursday, Jun 14th 1:29am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 10
Belleville, Michigan
81 323i |
yeah, and that was for a 323... i ended up replacing it with another one tho, just because i didnt' feel safe with the broken screws... |
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| jrcook320 |
Posted
Friday, Jun 15th 6:23am [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 1
Van Wert, OH
'81 320i |
Fuel CAN leak down past the plunger, there IS fuel pressure above the plunger and there is fuel flowing past the plunger. The plunger is the metering valve inside the fuel distributor that controls fuel pressure to the upper chamber of the FD. The fuel pressure above the plunger is the control pressure which limits plunger movement more as control pressure rises (eg as the motor warms up).
If you take the fuel distributor off of the air flow meter BEFORE relieving the fuel pressure, the control pressure on top of the plunger will blow the plunger right out the bottom of the FD. You do not want this to happen as even the slightest scratch on the plunger can ruin it. Ask me how I know...
There are no o-rings directly around the plunger rod, it is a precision machined fit tight enough to not leak. If your rod is worn or scratched it may leak and the whole FD needs replaced. Take the FD off, carefully pull the plunger out and check for worn areas. If none then you might as well try to replace internal o-rings. |
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| usang36 |
Posted
Friday, Jun 15th 7:22am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 36
Oregon
78 320i, 83 320iS |
There is ware in the form of a shiny spot on the plunger, but no flat spots or scratches. At least on my 83, there is a metal keeper that holds the plunger in the FD. Yea, last week when I pulled the FD off to see fuel leak real time, and possible see a relationship to the plungers protrusion out of the FD and the amt of fuel leaking, the plunger popped out past the keeper as you stated it would . At this point its leaky anyway. I have another used one to try that was a known good one, I will try that and see where it gets me. But first Im going to rule out some of the stuff above.
John |
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| jrcook320 |
Posted
Friday, Jun 15th 7:51am [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 1
Van Wert, OH
'81 320i |
The o-rings are on the outside of the control cylinder and as madhatter says they could be leaking. I would more likely suspect the control plunger to be leaking though. The control cylinder can't be removed without seperating the FD halves?
If the plunger shiny it's worn, even if it's too little to feel it could cause a problem. Why mess with the known leaking FD when you have a known good FD to try? |
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| usang36 |
Posted
Friday, Jun 15th 9:31am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 37
Oregon
78 320i, 83 320iS |
True, I hear you. But I have one that will never work again as the plunger has so much varnish it's stuck (from a 'parts' engine I bought), one given to me by a local friend that started leaking about 3 weeks after I put it on, and the original one that came with the car that's on it now. So you see, I have the luxury of taking one of them apart, probably the in op one. Somewhere in the world a Bosch fuel injection engineer will look up and scream as the halves separate, but I dont think he will get a fix om my local 
I keep thinking that this co incided with a spare WUR that I put on also, although I dont see how it could generate the problem..It was to troubleshoot a warm up problem that turned out to be the additional air slide. |
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| Madhatter |
Posted
Friday, Jun 15th 10:32am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 223
Australia - QLD
E21, E24, E30 |
if its varnished up, pull the head appart, remove the springs and seats, then throw the bottom half into a bucket full of diesel or kero and leave it sit for a week. Should strip any varnish off the surfaces and free it up. |
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| jrcook320 |
Posted
Friday, Jun 15th 3:51pm [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 1
Van Wert, OH
'81 320i |
why not try soaking it without taking it apart first? With all the fuel lines off the solvent will still fill the inside of the FD. Then you don't have to worry about getting it to seal again... |
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