92 318 i e36 driving me crazy

[mauricio]

first problem, sometimes the car don't start, starter working fine, no fire at all in any spark plug, but if i roll it down the hill starts right up, i shut it off and try again and this time starts fine.
second problem, i have to hold the engine above 2000 rpm at stop lights or anytime i stop, because sometimes the car shut off itself at iddle speed (sometimes) and wont starts again unless i push start it or let it roll down hill.
wierd: sometimes when it fails to start, i unplug and plug back again the iddle air control and starts, if this doesn't work i disconnect and connect the battery and starts.
what i have done: change iddle air control, fuel pump, fuel filter, ignition switch, dme/ecu, crank and cam sensors. sparks and wires.
parts tested: air flow sensor, trottle switch, ignition coils, harmonic balancer.
this two problems must be related.
please somebody must know what's going on with this car or i'm going to end in a sanatorium.
thanks.

[Jeron]

My guesses would have been crank sensor and ICV but you've already replaced those.

When you say the starter is working fine, are you sure it is turning the engine or do you just hear it spinning?

[mauricio]

Originally Posted by Jeron

My guesses would have been crank sensor and ICV but you've already replaced those.

When you say the starter is working fine, are you sure it is turning the engine or do you just hear it spinning?

yes, the starter is turning the engine.

[Jeron]

The reason I asked is because a bad starter solenoid can keep it from throwing out the starter gear.

I cant think of any relationship between the "no start, no spark" and the "dies at idle".

For "dies at idle" I think vacuum leak.

For the "no start" ECU, relay, crank sensor.

I know you replaced the crank sensor. Actually the crank sensor could be a link between the "no start" and "dies at idle" if it wasn't functioning at low RPM's but I dont see how that could happen.

Any reason to suspect bad wiring?

[mauricio]

Originally Posted by Jeron

The reason I asked is because a bad starter solenoid can keep it from throwing out the starter gear.

I cant think of any relationship between the "no start, no spark" and the "dies at idle".

For "dies at idle" I think vacuum leak.

For the "no start" ECU, relay, crank sensor.

I know you replaced the crank sensor. Actually the crank sensor could be a link between the "no start" and "dies at idle" if it wasn't functioning at low RPM's but I dont see how that could happen.

Any reason to suspect bad wiring?

the engine was tested for leaks at the dealership, after spending a lot of time and money they can't fund out what was wrong, i saw them scratching their heads.
the ecu relay is an option, i will replace it and cross my fingers.
i did check the wiring, didn't find anything wrong.
thanks.

[Jeron]

Have you checked the running voltage? Check at the battery posts, battery terminals and jump block under the hood.