1990 b350 MESS of probs

[Lukewarm256]

Originally Posted by alloro

I understand that the relay itself is good. But what I'm questioning is if the relay is getting energized or not (12v across the coil terminals).

understood.

well, from the relay, with key on, all but that large green wire is hot. when the key is shoved into the start position, and the engine cranks, the large green wire becomes hot (but very low voltage). SO, in the crank position, everything in the relay is hot.

now, when it is like this, there is still no voltage at the coil--none.

however, when i ground one of the wires on the relay (believe it to be the small green one) i CAN get voltage to the coil, but when i do, the injectors turn on full blast--if i crank the engine, there is no spark (even though the coil has voltage)... so it still wont start.

so, imho, the ASD relay is working, but something else down the line is not--either there are more fusible links in the harness than the 8 or so i found near the brake booster (one of which was repaired, and all of which now function)... OR there's a sensor problem, OR, the PCM is bad (which i cant afford to replace).

SO, from any of this, it give you an idea? because i'm compleatly stumped.

the next bet is to tear ALL the harnesses open, and go through it wire by wire.. and hope i catch something, because if i cant, it's going to be that 350$ PCM (which makes this 104k mile one ton get hauled to the wrecking yard).

[alloro]

There are no other fusible links besides the ones you found.

From your last description it does sound like the PCM is not working right. It's the PCM which energizes the relay and also controls spark, both of which you are not getting. You can get a used PCM in the range of $100-$150 off the internet.

I'm going on a day long trip today so I won't be back on until sometime tonight.