re: E30 idle problem/no power

[Dave Mulhouse <mulh0021@xxxxxxxxxx>]

>       There's been a lot of problems with idling on early E30's.  I have a
>84 318i, with the L-Jetronic fuel system.    Currently the car will idle
>weird when it's cold.  The idle is erratic, moving very quickly between
>500RPM and 1700RMP.  When driving cold, the car has NO power at low Rpm's.
>When I start the car warm, I have no idle problems, but the car still lacks
>power at the low Rpm's.  Another thing I noticed is that the car accelerates
>very slowly. 
>
>        This problem followed another interesting problem I just worked out.
>I ended up with a clogged cat. converter.  (Sucker was glowing bright orange
>down the NYS-thruway.)  I was experiencing poor gas mileage, and poor
>performance when the cat. converter clogged.  The reason it clogged was due
>to charred-up spark plugs (mixture too rich) and a bad O2 sensor.  I
>replaced the cat. converter, the spark plugs, and the o2 sensor.
>
>Any ideas on where to begin?  I'm still experiencing poor gas mileage.  I've
>checked over the cold start system per the Bentley manual.  All seems well
>there.  I haven't changed the fuel filter since I got the car in '95.  Can
>this be a problem?  Any chance parts of the cat. converter flew back into my
>muffler and partially clogged that?
>I've replaced spark plugs, rotor, cap, wires.  I'm assuming that this is an
>intake/fuel system/exhaust problem.


  First, you need to determine if the car is running in closed-loop
mode.  There are a number of procedures for doing this.  Check the
FAQs.  A cheap air/fuel meter gauge will work nicely for this job. 
(Yes!  These are not entirely worthless!!)  The LEDs on the gauge will
bounce up and down if the car is running closed-loop.  I have one
installed on my 318i.  Costs about 30-40 bucks.  If the car IS running
closed loop when in should, there could be a mechanical problem
somewhere, or a heavy foot...  If the car never hits closed-loop, there
could be a number of problems.  Bad temp sensor (remember the L-jet unit
doesn't read the same one you see on the inst. cluster.), bad air-flow
meter, plugged injectors, electrical problems, bad L-jet unit, bad
ICM/ICV, etc...  Whatever it is, you need to find the problem or risk
another cat failure.   The Bently manual has procedures for testing all
of these items.  And, if they are available yet, get Brett Anderson's
new E30 repair manual.  I'm sure it is going to be great.  Does anyone
have new info on release date of his book?

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