WTF Black Box

[SoopaGhetto]

Im trying to figure out why my car is having a hard time starting.

im looking around in the engine bay and see this black box with a small red led on top located on the passenger side shock tower. I nvr seen this in any e30. it looks to be some sort of an alarm as two wires are going from the unit to this huge horn. the unit looks factory mounted; its wired/jumped to fuse 16 and 26. I looked at the fuse diagram and those are "not used"

any idea what it could be?

i will post a pic shortly...

[jlevie]

That just about has to be some sort of after market alarm. It may, or may not, have anything to do with your starting problems.

If the engine won't crank or won't fire when cranking the alarm could be a player. If it is just hard to start, other causes (intake leaks, fuel system issues, spark issues, etc) are more likely.

[blocke]

It's "the man" keeping tabs on you. The huge horn is in fact a microphone.

If you unhook it, does the car start any better?

[SoopaGhetto]

i havent tried unplugging it just yet. Anyone know what fuse 16/21 does IF it is being used by something?

The hard start has been gradual. longest time it ever took to start was 6 tries. today i had to crank like 11 times then it started. i tried replacing fuel filter, spark plugs. i am getting fuel/spark but it seems to be intermittent. If the alarm was interfering then that would make sense.

first/early morning starts are always definitive. after driving for a bit, its up in the air. been lucky thus far. I had a weird pulsing sensation when accelerating and during steady state normal cruise. I tried disconnecting the o2 and it lessened the pulsing but its still there. Ive been searching a lot these past weeks too find someone with the same probs.

oh god n00bness: i have a 86' 325es

[Kershaw]

picture?

pulsing could be a number of things. i'd get it when i first started the car and drove around a bit, it was a bad throttle position sensor.

[SoopaGhetto]

as you can see the black box is mounted nicely like its supposed to be there. and its old...



the horn is spliced into two wires coming from the black box...unless the horn is actually a microphone...




the wires coming from the black box looks to be spliced into the fuse slots 16/26. that looks like a really good hack job



you can see the black harness connected using a white 3 prong connector and from there it goes to the fuse box

and before anyone says it, i know the o2 sensor is disconnected


i havent removed the black box yet. ima do that in prolly an hr or so. until then moar research i suppose :wgaf:

[2.5-12]

alarm systems dont cause hard starting, some were equipped with an immobilizer which would cause the starter to not engage or for the system to cut spark or fuel pumps (less likely)

I would put money on your problem being fuel, spark or intake vacuum related.

[SoopaGhetto]

alarm systems dont cause hard starting, some were equipped with an immobilizer which would cause the starter to not engage or for the system to cut spark or fuel pumps (less likely)

I would put money on your problem being fuel, spark or intake vacuum related.

yea i thought maybe this unit would cut out fuel pump or dme, but that being the case only if fuse 16/26 isnt just power/ground in some way.

what would cause intermittent hard starts? from my search, it seems like there are definitive diagnosis if the problem is consistent or has a pattern.

symptoms:
*pulses when accel or cruising
*easy first starts of the day. easy starts when warm/hot but a few times no
*idles good. a little lumpy at times
*wot hits a brick wall around 4000rpm...my hard limiter hits 5300rpm

what i have done:
-external fuel pump is whirring (unable to hear the intank)
-unplugged o2; pulses subsided
-switch afm with a known good one. no change in pulsing
-valve adjustment
-replaced fuel filter, spark plugs (old ones were a nice light doodoo brown on the proceline).
-checked for vac leaks. non apparent.

what i will do:
-check crank sensor (i know there is one on the front but etas have one elsewhere right?)
-check evap crap again
-check cap/rotor

what i think:
im thinking it may be the crank sensor, but my car nvr died on me on the road. brick wall seems like fuel issue or crank sensor issue.

when ever i open the oil cap with the car running, it would idle up then level off; once i put the cap back on, the idle returns to normal. if there was a vac leak, wouldnt the higher idle remain?


this bitch is more hard to diagnose than syphilis at stage 3

[2.5-12]

you can replace the CPS if you want, I really don't think thats going to do anything for you because they are kind of all-or-nothing sensors.

so you have a 325i, 325e or a 325e(superETA 88'+)?

I have similar symptoms with my convertible, it'll start right up in the morning, but if its even a little warm, I have to crank for 6 seconds, twice. to get it to start.

my HPFP is also whirring, but I am convinced its my FPR (which I would check and change in your case as well) because my rough idle and extremely rich running makes me think its the FPR.

I also get hesitation when caning it about 4,500rpm but then the hesitation stops, the CEL comes on and it goes like hell. the CEL goes off when I let off.

clean your cap and rotor with a wire brush, check your ignition coil and battery voltage and swap your FPR before your reference sensor IMO.

[SoopaGhetto]

you can replace the CPS if you want, I really don't think thats going to do anything for you because they are kind of all-or-nothing sensors.

so you have a 325i, 325e or a 325e(superETA 88'+)?

I have similar symptoms with my convertible, it'll start right up in the morning, but if its even a little warm, I have to crank for 6 seconds, twice. to get it to start.

my HPFP is also whirring, but I am convinced its my FPR (which I would check and change in your case as well) because my rough idle and extremely rich running makes me think its the FPR.

I also get hesitation when caning it about 4,500rpm but then the hesitation stops, the CEL comes on and it goes like hell. the CEL goes off when I let off.

clean your cap and rotor with a wire brush, check your ignition coil and battery voltage and swap your FPR before your reference sensor IMO.

i have an 86 es with round connector harness. and yea i thought the cps would either work or crap out completely.

i removed that black box...most worthless piece of crap you could put on your car. i seriously have no idea what it does. terminal 16 is ground when car is off and its +12V when the car is running. Terminal 26 is hot +12V all time. Then ground and two connectors for the that speaker thing.


i rerouted the fuel tank evap it before the afm after the filter in the airboxx. (love stock mods)

checked for other vac leaks and couldnt find any cracks and such in vac lines

jumped the fuel pump and it turns on everytime but havent tested psi value yet (so relay could be sticky or dme not sending signal at times, or enough pressure either from fpr or pump)

forgot to check cap/rotor and coil. do i have to remove the freakin radiator? such a tight clearance. m10s are way easier to work on ahhahahahah :puppy:

[SoopaGhetto]

anyone?

Im thinkin of just going to megasquirt again. tired of the old shit!

[SoopaGhetto]

so i noticed something new today...


drove to campus, parked. Car quickly started on first try from my apt (i didnt drive all weekend either) after class, went to start the car and it just cranked and cranked. I noticed the rpm on the tach was at 0 and stayed there while cranking. I stopped cranking, gave it a second, cranked again and noticed the tach at 0 then jumped to ~300 rpm and it started up. took a few seconds to crank but started fine once rpm was present.


Since i wasnt getting rpm on my first attempt...wat could the prob with that be? also all my cluster lights were illuminated until i reved a lil then they went off. so odd but seems to be related?

[2.5-12]

tachometers are electronic, they arent linked to the engine in any physical way.

your symptoms suggest a worn component. all of which I would try are listed in my previous posts.

[SoopaGhetto]

tachometers are electronic, they arent linked to the engine in any physical way.

your symptoms suggest a worn component. all of which I would try are listed in my previous posts.

i figured as much. i havent had a chance to test cap/rotor/fpr (i know its not leaking though from vac line removal). i thought maybe there is a reason for no tach not causing a start but it may be the other way around.

[jlevie]

so i noticed something new today...


drove to campus, parked. Car quickly started on first try from my apt (i didnt drive all weekend either) after class, went to start the car and it just cranked and cranked. I noticed the rpm on the tach was at 0 and stayed there while cranking. I stopped cranking, gave it a second, cranked again and noticed the tach at 0 then jumped to ~300 rpm and it started up. took a few seconds to crank but started fine once rpm was present.

Since i wasnt getting rpm on my first attempt...wat could the prob with that be? also all my cluster lights were illuminated until i reved a lil then they went off. so odd but seems to be related?

That would suggest a problem with the main relay, fusible link, timing reference sensors, or ignition switch. The lights remaining on could be a weak alternator or ignition switch. Either could be caused by high resistance connections in the primary power circuits or a weak battery.