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Posted
Thursday, Aug 5th 6:09am [Edit] [Quote] [IMS] [View car] |
Post nr. 2
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Is there a reliable way to set CO by using an air/fuel ratio mter/gauge? I've checked old posts and not found much on this. |
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Posted
Friday, Aug 6th 3:38pm [Edit] [Quote] [IMS] [View car] |
Post nr. 42
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I suppose you'd wanna set the mixture so that you light up about half the lights on your AF meter during full throttle acceleration. What type of AF meter do you have?
jamie |
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Posted
Saturday, Aug 7th 2:24am [Edit] [Quote] [IMS] [View car] |
Post nr. 3
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Theres not a name brand on it, but I am told it is made by Halmeter. Specifically I am curious about idle CO and where the meter should read with the O2 sensor disconnected from the DME. Here in E. Tenn we do not yet have emission testing so nobody has gas analyzers. I am trying to revive an '82 that has been abused for many years and some hack mechanic has tried to compensate for massive vaccum leaks by enriching the mixture and closing the idle bypass. I need to baseline this thing before I throw the turbo to it. |
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Posted
Saturday, Aug 7th 2:59am [Edit] [Quote] [IMS] [View car] |
Post nr. 723
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to more or less baseline the fuel mix from the distributor either bring the allen key left (leaning the mix) or right(richening the mix). Since you said they tried to overcompensate for air leaks you would need to move the mix control screw to the left.
Once the car is more or less running on its own, and warmed up without help from the throttle. Take the allen key as far to the left until the engine begins to stumble. This is the farthest lean adjustment. Bring it back to the right until again the engine begins to stumble. This is the farthest rich adjustment. You can mark these positions mentally or whatever helps you. Now you will need to bring the mixture screw to a point between these two farthest settings or points. Roughly this is the middle of the adjustment scale. Not perfect but then you will not fry your pistons or burn a valve due to a lean condition or flood your engine with gas.
From here the car should be running at a decent idle and should not smell like it is not burning all of the gas. If the engine sputters and dies you may still have a vaccum leak. Set the timing and check your revs at idle. Too high you will need to adjust the air mix screw in a bit to lower the revs. The reverse if the revs are low.
Idle can stay up if the aux air valve is stuck in the open position due to a faulty valve. Checking this requires a freezer and a hot oven(275deg F). in the freezer the valve will open all the way. In the oven it will close and hardly let any air through. Water heated aux air valve can be checked the same way.
This is more or less a rough adjustment and is what I have used on my 323i. I get decent gas milage with the four speed and 3.45 rear end for a total of 364 miles to the tank at 6000+ feet of elevation. With the above setting your electronic air fuel meter should be at stoich or a little lean. You adjust as you deem necessary. Also check with your A/F meter during accelleration it should richen as the WUR does its job. Of course location and age of the engine will yield better or slightly poorer results. |
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Posted
Saturday, Aug 7th 4:41am [Edit] [Quote] [IMS] [View car] |
Post nr. 4
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Thanks guys, but heres what I'm up against. I am familiar with the rich/lean adjustment process, and I can get the car to run well at a warm idle. Aux air valve opens and closes, however I don't think it opens all the way when cold. The valve guide seals are almost nonexistent so it smokes badly on startup. The above two issues combined make cold starts a bear. But after warmed up and in closed loop operation, I get a lean stumble at highway speeds when the a/f meter goes lean. When lean, the meter drops briefly off the bottom of the scale. I can not readily find any more vaccum leaks, I have repaired many, including injector seals. All control pressures from the WUR are correct, I have correct system pressure, Cold start injector operates properly and does not leak, injector patterns are ok if not great. Compressions are 150's to 160's. Timing is on(ignition and cam), valves adjusted. I'm kinda running out of places to look, and yet I know I'm close. Info overload I'm sure, but what is the outside perspective? |
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Posted
Saturday, Aug 7th 4:53pm [Edit] [Quote] [IMS] [View car] |
Post nr. 724
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you say the valve guides are leaking you may want to check the spark plugs for fouling. That would be the only things left along with the rotor distributor cover coil and wires.
Injectors might need to be checked for flow as well to see if they are flowing more or less the same amount of fuel.
You could also have a bit too much carbon stuck to the combustion chamber. Some sprited driving at about 4000+ revs will help some or find the thread on water injection in this forum. |
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Posted
Sunday, Aug 8th 7:42am [Edit] [Quote] [IMS] [View car] |
Post nr. 6
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I Swapped plugs out with factory plugs and Fuel injectors/distributor is within 10%. I thought I'd check with you guys before I got really deep, But I guess I going in. I have a spare head I'll rebuild and install. I will let you guys Know what I find. Thanks again! |
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Posted
Sunday, Aug 8th 8:07am [Edit] [Quote] [IMS] [View car] |
Post nr. 43
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do you have a CIS pressure test kit? |
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Posted
Sunday, Aug 8th 2:38pm [Edit] [Quote] [IMS] [View car] |
Post nr. 7
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I Have access to the gauge and 2-way Valve. |
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Posted
Monday, Aug 9th 7:52am [Edit] [Quote] [IMS] [View car] |
Post nr. 44
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I'd recommend you check your cold and hot pressures. It's amazing how many strange problems can be caused by a faulty WUR. It's easy to set up and test so I'd do it! |
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Posted
Monday, Aug 9th 2:28pm [Edit] [Quote] [IMS] [View car] |
Post nr. 10
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I have checked and adjusted the WUR according to an obscure BMW TSIB from 1982. Allpressures are correct, as well as the system supply pressure. |
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Posted
Tuesday, Aug 10th 4:04am [Edit] [Quote] [IMS] [View car] |
Post nr. 51
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| myersport wrote: | | I have checked and adjusted the WUR according to an obscure BMW TSIB from 1982. |
TSIB? Is this something online you can share? It might help me out. |
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Posted
Tuesday, Aug 10th 4:42am [Edit] [Quote] [IMS] [View car] |
Post nr. 12
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I was BMW tech until about 3 years ago and have much info and old dealership manuals and service/sales literature on 320i's. The only place I know of this info online is BMW's TIS website for the techs, but it is firewalled and you need multiple passwords to get in. The reason for my original posting is I've hit a roadblock in simple trouble shooting and was looking for a gem of outside observation. The tech schools train you that when trying to isolate a difficult problem, find everything that is right and the problem lies with what is left. Well it seems that everything I test is right or I have made right but with no ultimate success, just minor improvements. I am now convinced that the head needs to come off for internal engine examination. Like I said, this is a perplexing problem and i'll definetly let you guys know how it turns out! |
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Posted
Wednesday, Aug 11th 12:48am [Edit] [Quote] [IMS] [View car] |
Post nr. 45
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I just re-read you descriptions above, had another stab in the dark to share
you mention it drops to lean- possibly a fuel pump or fuel pump relay issue, resulting in momentary lack of fuel pressure?
jamie |
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Posted
Wednesday, Aug 11th 1:31am [Edit] [Quote] [IMS] [View car] |
Post nr. 14
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Fuel pressure as checked while running remains constant. I was refering to the A/F gauge cycling in closed loop. It just seems to cycle leaner than it should. It's also possible that that is the way the meter is set up to read. I should probably hook it up to my 2.7 and compare readings, I just haven't made the effort.
--Dennis |
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