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Discussion Starter #1
I have a 1985 E28 with an M30 5sp. My motor hesitates throughout the rev range, and really starts choaking at around 4500 RPM.

To give you an idea about the condition of the motor, I bought the car about 2 years ago, and my valves were clacking so I took off my valve cover to adjust them, and to my surprise the head looked completely new. Even the cam, everything. Well to continue, I checked my compression, and I got as follows :
181 181 180 182 181 181 which I think is pretty good.

Anyhow, I have new spark plugs, changed my cap and rotor, and air flow meter (though, it isnt in my car right now, because it actually runs a lot better with the old one, no matter how the newer one is adjusted). Only thing that I haven't changed is the spark plug cables, and the ECU, but I had the ECU apart 1 year ago because my car wouldn't start because I had a loose solder in the ECU. That was fixed, and I had a good look at that thing, and it seems to be in excellent condition now. Oh, yeah, I have good fuel pressure as well, and all electrical contacts are clean.

I really want to know what I can do to this car to make her roar like she should.
 

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fuel pump filters or air filters... I dont know what else could be wrong since you eliminated a whole bunch of stuff

good luck
 

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Discussion Starter #4
So you are saying if the old air flow meter works better than the new one, I should still use the new one? Do you know what the factory adjustment settings are for it?

Thanks.

BTW, I have a K&N cone filter, with my own ghetto bracketing system, so it gets pleanty of breathing
 

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all im saying is that maybe the old one finally took a dump or is dirty.

If you use a K&N filter, the oil could have caused buildup on the air flow sensor - causing inaccurate readings. try cleaning it with a soft cloth and make sur ethe gunk is off (if its on there) I was just suggesting trying the new air flow sensor and if it works, then theres your problem and you saved some time, and if not at least thats one thing you know is not the problem.

good luck :)
 

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Obviously you are losing fuel somehow. Either your mixture is very lean or your fuel volume is not up to par. You can have all the fuel pressure that you want and still not have ample fuel delivery. So either not enough fuel is making it to the injectors or the injectors are not delivering enough fuel. You just need to figure out why. I would seriously suspect a weak fuel pump (the car is old). The new air flow meter is just a little more accurate which means that it is leaning the engine out even more. So the new meter is good but the old is just running a little richer and helping the engine slightly. Focus on fuel delivery and not the fuel pressure. You may even need to have the injectors checked and/or cleaned.
 

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Discussion Starter #7
Well, I know that I have good fuel pumps in my car, I know for a fact that everything is working well, except for my injectors, I just keep on pumping fuel injector cleaner in those.

Anyhow, I will have a look at the fuel injectors themselves.

Thanks guys
 
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