Cold start symptoms

[Huck]

#1--1987--325ic--Cold start---?? If I get into the car, turn the key and watch all the lights and the fuel pump build pressure then attempt to start the car--it cranks fine and trys to start but ---it doesn't. If I depress the pedal opening the throttle body---it will start, run a bit rich, then smooth out and run fine. No other symptoms or problems at all!!! Just that cold start PITA. Now the car can be warm after running errands etc. but the first attempt at restarting may again require me to push the gas pedal down to start. thoughts__________.
#2--I do have lots of running noise from the rear. i can feel play in the drivers outer wheel bearing and am planning on replacing that soon. Could one worn bearing create enough noise to sould like the differential and more bearing are all kaka? I do have a good replace diff available but don't like throwing parts into my car unless I know what is bad as I usually tend to create more problems then I fix. Would you replace both outer bearings if only one shows play when you try to wobble the wheel when jacked up??
Thanks---Huck

[Mike325]

Not too sure on the cold start, but for the bearing, yes one bad bearing could create lots of noise and make the car sound like it has more of a problem than it really does. You might want to consider replacing the other bearing because if one goes bad, the other one could soon follow. The only thing is that maybe the other one was replaced before you got the car, so I would just leave it and keep it in the back of your mind.

[E30_(1st Musk)_]

im having a cold start problem also..but since none can really diagnose anything over the net. the best choice is this....

http://r3vlimited.com/board/showthread.php?t=164030

the bentley manual has alot of options. and ways to test faulty systems

[Mike325]

I know my eta had this problem once and there is a cold start valve that was not working. No sure how it is n your engine, but that is what I would look at first.

[Fcknslo]

what do you mean it was not working? what was it doing because I'm having some problems with starting and someone told me to look at the cold start.

[Mike325]

The sensor that should allow more fuel into the engine when it is cold would not work. It was getting power, but it was a dead sensor. The car would crank for a few seconds then sputter to life like it was just getting enough fuel to start. Would take about 5 seconds for the car to start. The cold start valve is in the coolant and goes off of the water temps. If you have a bently, look in there. I had to use my volt meter to diagnose it.

Here is the part from real oem.

I think that it was #13 or #14. Located somewhere on the top side of the engine, but like I said, the bently will help you locate it.

[Adrian_Visser]

you're over simplifying the system quite a bit there what you are thinking of is the coolant temp switch it controls the cold start injector on early cars.

[Need4Speed1299]

you're over simplifying the system quite a bit there what you are thinking of is the coolant temp switch it controls the cold start injector on early cars.

x2

Its #14 in the above diagram.

[Mike325]

How am I oversimplifying it? All he needs to do is check the sensor to see if it is getting power and then see if the sensor is working be checking the ohms or voltage (I forget) at the sensor to see if it is still functioning correctly.

[jlevie]

Idle or hard starting problems are most commonly caused by intake leaks and/or
a sticky or defective Idle Control Valve (ICV). The only reliable method of
locating intake leaks is to have a smoke test run on the intake and crank case
and to test the brake booster with a gage and vacuum pump. The complete list
of possible causes of an intake leak is:

Intake boot
Throttle body gasket
ICV hoses & connections
Brake booster, hoses, and connections
Crank case breather hose
Evaporative control hose and valve
Fuel pressure regulator & hose
Injector seals
Valve cover gaskets & bungs
Oil filler cap
Dip stick o-rings
Oil return tube o-rings

While leaks in some of those can be found by inspection or by spraying carb
cleaner on suspect areas, not finding leaks that way doesn't eliminate the
possibility. Only a smoke test will really work.

Once the possibility of intake leaks is eliminated, the ICV needs to be
removed and cleaned with carb cleaner until the vane inside moves freely. When
the ignition is switched on you should be able to feel vibration from the
ICV. If no vibration the ICV is bad, there's a problem with its wiring or
connector, there's a problem with the TPS, or the DME (or Idle Control Module
(ICM) on an ETA car) is faulty.

For the DME (or ICM) to control idle, the idle switch in the TPS must work
correctly. The switch should close when the throttle stop is 0.020-0.060" off
the idle stop screw.

The fuel system should be tested via the suite of tests in the Bentley manual
as invalid rail pressure can be a contributor to idle and starting problems. A
simple injector check is to pull the injectors, jumper the fuel relay to run
the pump, and see if the injectors are leaking. You can also point the
injectors into a towel, remove the coil wire, and crank the engine to see if
all of the injectors appear to be spraying in a similar fashion. The best
approach to possible injector problems is to have the injectors cleaned and
flow tested. Since raw fuel can or will be released in these tests, have a
fire extinguisher handy.

The O2 sensor can be a contributor to idle problems. The O2 sensor is a
scheduled maintenance item with a useful life of no more than 100k. If the
sensor has that mileage or more (or is of unknown age), replace it.

The AFM can be a contributor. If the vane doesn't move freely or the
resistance track is worn the DME may be receiving invalid data from the
AFM. And if someone has fiddled with the bypass air adjustment the DME may be
unable to stabilize idle. The bypass air adjustment should only be adjusted
per the procedure in the Bentley and with an exhaust gas analyzer. And even
then everything else associated with engine management has to first be
operating properly. If the AFM becomes a suspect, replacement with a good used
unit is the best approach.

Improperly adjusted or malfunctioning valves will affect idle and starting. As
can compression issues from ring or cylinder wear. A valve adjustment is
called for every 15k. A useful diagnostic is to run compression and leak down
tests on the engine. And aged ignition wires, plugs, distributor cap, or
rotor can cause problems. Insulation does break down with time and heat. And
since the youngest E30 is going on 19 years old, if the ignition system is
original or the plugs are old replacement is indicated.

Although not usually a problem, a bad DME temp sensor is a possibility. That
generally won't cause an unstable idle, but can cause hard cold or hard hot
starts and/or a rough idle. As can problems with the timing reference sensors.

When all other possibilities have been eliminated and idle or starting
problems persist, replacement of the DME, or if applicable the ICM, is
indicated.

[Huck]

Holy Crap Batman---there are so many things that it could be-----how about a best guess considering that 1 minute after the car starts, it runs perfect. At this rate, I think I will just push the gas pedal down to start the car and live with the rest. Huck