Mysterious black box on m42....

[joecivic]

Well, i've been trying to diagnose the problem my '91 318is has for about... 3 or 4 months now. No luck...

Car hasn't started in months now...

Here's what i've tried:

check fuel pressure: 55psi
check compression: good
replace afm: (wasn't getting signal... am now)
check crank and cam sensors... seem good.
Put noid lights on injectors: Iratic firing, but signal none the less.
Check spark: good

There doesn't seem to be any fuel exiting the injectors... so obvoiusly no starting

There is a black box under the intake manifold that both the cam and crank sensors are plugged into... but i can't find any explanation on the box. I suppose it could be a simple junction box, but i can't find any mention of it in the bently, or the snapon wiring diagram.

Anyone got any info on the mystery box? Any ideas AT ALL??? If you've got an idea, you're way ahead of me... i'm lost and i need a car :(

[randomtask37]

*bump*

good luck

[nickmp0wer]

interested in selling it?

[Spaz]

picture of the box would help :)

[joecivic]

I can't get a pic. of it, but its literally a small black box.. :-/

not interested in selling it right now. The car is in good shape... better if it'd start. but for shits and giggles.. what price did you have in mind?

[nickmp0wer]

depends where u live, i wouldnt pay 2000 and the same for shipping

i actually know what box ur talking about and im pretty sure it goes to the computer, check to make sure everything is pluged in well

[joecivic]

I'm located in sw va, more specifically blacksburg, va. (24060).

If you're close and interested we'll talk.

I'll check more on that box asap.

[e9nine]

Is this "box" beneath the intake mani? If so, its just part of the main harness.

[joecivic]

it is indeed. Well, i'm lost then... i have no idea what's keeping it from running... but i'm certain its going to be simple. :(

[Rob]

Re: Mysterious black box on m42....

check fuel pressure: 55psi


There doesn't seem to be any fuel exiting the injectors... so obvoiusly no starting

OK, these seems to contradict each other, perhaps you have a crimped fuel line between the pressure gauge and the rest of the system?

[e9nine]

Does the car crank?
How strong is the battery?
Have u tried jumping it?
Have u tried pushing the car?

[kylebes1]

I would replace the fuel lines to the injectors and maybe even the rail, do they ever go bad?

[joecivic]

they don't contradict each other. Pressure is behind the injectors, but they aren't firing. there is no crimp, and the lines (only the rubber lines, the metal lines are fine) are brand new.

i think it IS possible that the injectors are clogged since when i got the car there was no fuel filter.

Only prob w/ the clogged fuel injector theory is that it seems highly unlikely to me for the injectors to ALL be clogged... eh well.

[kylebes1]

go pick up a couple use ones and see if that is actually your problem

[Rob]

what i meant was that if there's fuel pressure, there should be fuel from the injectors, IE the problem is after where ever the FP gauge is...

clogged injectors could be it, i have no clue though