Hi; i've got no voltage showing at the coil when i have the key on; shouldn't i be getting a voltage reading on the positive side of the coil? thanks

 

Yes ... and no. After a few seconds of not running (about 2), the ASD should drop out to stop the fuel pump from, well, pumping gas out a busted line. And the ASD also powers the coil and the TBI injectors (same reason; KILL the SOB if it's not running!)

You'll want it running, or to jump the ASD, to check for voltage at the coil.

RwP

 

Hey buddy; thanks for the input. we had the old truck running good with a new idle control valve and after a few tries, the motor never would idle down ....we ran that hex nut on the idle control part in all the way to keep it from racing. my buddy went to fooling with the distributor, i think to help lower the idle, and he has his big hands down in there...bumped his hand against something back behind the dist. and the truck just shut off and won't start. Is there wire back there running to a sensor maybe that would have killed it? thanks for the help

 

Heh. Did you ever run through the idle speed instructions for a TBI motor?

As to behind there - no, but you do have the wiring to the distributor.

There's also chassis wiring to the coil.

That could also be a failed ASD relay; or a failed ASD fuse.

You'll really need to find someone with a 1991 Factory Service Manual to start proper troubleshooting.

RwP

 

wouldn't a haynes or chilton be as good as a factory service manual? i only found one fsm so far on amazon and its 60bucks

 

No, the haynes/chilton are REALLY generic, and don't include a lot of information that the FSM has. (like, accurate wiring diagrams.....)

There *might* be some manuals available for free download around here somewhere......

 

The wiring for the crankshaft position sensor is back there, a broken or disturbed connector would produce a no-start situation.

Steve

 

i'm pretty confidant that this 91 does not have a crankshaft position sensor, right?

 

can't find a free fsm online, just this used one:

 

For wiring?

No.

Matter of fact, throwing colored straws on the ground would probably do better than Haynes and Chiltons do for wiring diagrams.

I find them starting at $30 on Ebay (yes, used will also work.)

RockAuto lists the DVD version for $22.99 ... I'll suggest that the paper may be better, since if you modify, you can note in the paper copy easier. But I usually do lookups etc. on my PDF copy (came on a DVD); I then print what I want, even though I have a paper copy on the shelf also.

RwP