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1990 b350 no spark/fuel
03-25-2011, 11:40 PM
Have replaced the asd, coil, even the computer. have chased down wires in the harness--have gone to hell and back to figure out this problem.
the van will crank, everything comes online, but injectors never fire.
the coil never gets voltage. ever. infact, with a test light, both sides are grounded. neither is ever hot, or anything but a ground
SO, i have no fuel, AND no spark, but it will crank all day.
nothing really changed since replacing the pcm--aside from a few more things work that didnt... (like the electric choke).
it was hotwired a few times using the alternator (i didnt do this, but i saw it done) at the time, it made no sense to me and doesnt really now. but it would get it to start. considering the sizeable sum i spent on the pcm, i'm not doing that again. BUT, the alternator, with key on, is hot on every connection but the large ground (think there's 2 hot wires) is THAT normal? i figure if it worked to hotwire the alternator to get it started, maybe it's cooked, and keeping it from it now? the idiot light behind the voltmeter is always on as well.
anyway. ANY possibilities for me? where is the crankshaft position sensor?
have looked into the distrubutor--rusty as hell in there, and cant get the rotor off. is there a sensor in there that could be bad? has 3 wires going to it--none are ever hot.
there's a sensor near the distrubutor, a large round thing--one side is hot, the other side never is (even while cranking)--what is this? does it matter?
i have another set of posts with everything i went through before replacing the pcm/computer... incase it's any insight.
i need this thing to be fixed, something desperatly.
03-26-2011, 11:31 AM
1. The large sensor next to the distributor is the oil pressure sender.
2. There is a pick-up coil inside the distributor, under the rotor.
3. You problem is no power getting through or shall I say coming out of the ASD relay. The ASD relay supplies power to the ECM, the injectors, and the ignition coil. Have you checked the fusible links to see if any are burnt?
03-26-2011, 07:12 PM
yeah, have checked the fuseable links last year (when the weather wasnt aweful, this is alaska) .. found one burnt one, repaird it. before the repair, it wouldnt do ANYthing, just the heater blower would work. after than repair, i reached the point where i am now.
i have checked the asd relay, i have replaced it with working ones, i have tested them all, and they all test fine. the OUT volts are very low when it works, but it works.
 ... when it was hotwired with the alternator, anytime the engine reved, the volts, and lights would soar--this MAY have damaged something, a sensor or other thing, that i dont know about. an idea would help.
i'm more than stumped, because of that...
would you know why, in the past, it would run when a hotwire was put to the alternator? is this a red-herring, or is there something to this?
is there anything i can do to bypass the asd? i remember trying to trace the wires as far as they would go .. i never found another bad one, or another bad fuseable link....
this has warped my brain to nearly breaking.
03-27-2011, 12:35 PM
If you unplug the relay, you can take a short length of 12 gauge wire and jump from pin 87 to pin 30 and it will be like the relay is on all the time. This will of course drain your battery if the jumper is left in.
03-27-2011, 03:13 PM
i jumpered the relay.
there is a red wire, always hot, dark blue that works with the ignition, and works (rules out my switch), a dark green--which powers everyhting that isnt working for me--and doesnt get hot when ignition on, and a dark blue with a little yellow stripe--which works when the ignition is turned on.
SO, the relay will work for the little wire (db/yl) but not the dark green.
i left the relay on, and put a hot wire on a switch to the dark green.
THERE IS LIFE! it runs and starts. had done it before i got the new pcm/computer, and this didnt work... SO, brain needed to go anyway.
will get ANOTHER new relay to see if this is it. will re-do the wire ends incase THAT is it (they look ugly as sin). and if that doesnt work, the thing will run off a toggle...
THANK YOU alloro ... for your YEARS of advice :D
03-28-2011, 08:06 AM
Notice in this diagram how the DB/YL wire runs to the diagnostic connector. You can use that as a test point to see if that wire powers up and down as the key is turned on and off.
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