Re: Won't Start NEED HELP

From: Bob Tom (tigers@bserv.com)
Date: Sun Feb 27 2005 - 12:09:55 EST


At 06:34 PM 2/26/05, you wrote:
>No I haven't but will now...I take it it's in the panel with the rest of
>the relays
>and marked asd? I'll look now.

Yep, in the Power Distribution Center, right next to the fuel relay. A diagram
on the back of the PDC lid will show where everything is.

What I like to do, in addition to using a DVOM or DMM to measure resistance
and continuity, is to actually see if a part is moving when it is supposed to.
For this, a helper is needed.

My son (the one with the skill/knowledge) looks/measures/fixes and I (the
helper)
work the ignition key :-) We remove the ASD and fuel relays, use a small flat
head screw driver and gentling pry the caps of the relays, put the relays back
in. I'll turn the ignition to ON and he watch to see if the relays close
i.e. energize.

If they energize, then I'll crank the engine to see if they remain energized.
With Dodge, if the pcm does not detect a 'viable' return signal from the
crankshaft position (ckp) sensor and/or the camshaft position (cmp) sensor
by about 1 sec. from cranking, the pcm will de-energize/open the ASD relay
and the (I think) fuel pump relay.

The FSM describes a long relay test but I only use it if the above fails
and therefore might be a problem with the relay itself.

BTW, when the ignition key is turn to ON and everything is aok, the fuel pump
will just run for a second or so and then not pump any more fuel. So if you're
using a test circuit light, that's why the light will flash on and then off.

If any of these tests fail, then more diagnostics need to be done. I only
say this so you don't immediately think that the computer is the culprit.

The next test, if needed, is to determine if the problem is on the ignition
or fuel side. Ignition would be the easier to rule in or out. Test for spark.
Disconnect a spark plug wire, put a philip screw driver in the end of the wire,
position the shaft of the screw driver about 1/4" from a good ground (hold
by the insulated handle and watch that your body doesn't touch any metal
... 40k v is a pretty good wake-me-up :-) ), have helper turn crank the
engine, and look for a strong (bluish) spark. If spark then fuel side is the
problem. If no spark the ignition side is the problem although the fuel side
shouldn't be ruled out at this point.

On the fuel side, if you've got a test port on the fuel rail, testing the pump
is fairly simple ... a little more complicated if no test port.

The 'oldest' Bob



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