300M Ignition Problems

[Dave]

I just did a hell of a lot of work to my 99 300M and now that it's all
back together it won't start. The car has 115k miles. I had an O2
sensor back out of it's thread, and decided to go ahead and relpace a
number of things at once. Before the O2 sensor had backed out, the
car ran fine - great even. I replaced the timing belt, water pump,
serpentine belt, serpentine idler pulley, AC belt, one O2 sensor
(forward sensor on driver's side), and all 6 sparkplugs.

When it was all back together, I went to start the car and found that
the battery had died (it was sitting for about 2 weeks). I went ahead
and replaced the battery as well because it was the original that came
with the car. When I put the new battery in, I noticed that the leads
were badly corroded. Anyway, I had power.

The FIRST time that I tried to start it, it turned over but didn't
fire. The SECOND time I tried, it would not even turn over; the
voltage would drop when turning the ignition key to ON, and when
turning it to START, I got a clicking noise like a weak battery. My
guess was that the corroded terminal leads needed to be replaced, so I
replaced them. Now, I can turn the car over, no power drop to ON, but
there's no spark at all at the plugs.

Here's the details - I was careful to ensure that all of the timing
marks were aligned on the timing belt cam pulleys and the crank
pulley. I've double-checked the gap on all of the spark plugs. I get
no spark at the plugs when turning over the engine. I get no power on
the green lead to the coilpacks with the ignition key ON. I do have
continuity between the ASD relay and the coilpack leads. I have power
to the ASD relay from the battery, and I'm assuming that the PCM is
shutting down the ASD relay. I haven't yet got up the courage to jump
the ASD relay to see if I can get spark to the plugs, because I'm not
sure what else is controlled by the ASD relay (I expect it's only the
fuel pump, but I'm not certain). I tried the ON-OFF-ON-OFF-ON trick,
and the only code was the one that the battery had been disconnected
in the last 50 starts.

Any assistance/advice/help would be greatly appreciated. I'm going
broke using my wife's Expedition as a commuter car.

-dave

 

[Ted Mittelstaedt]

I just did a hell of a lot of work to my 99 300M and now that it's all
back together it won't start. The car has 115k miles. I had an O2

Any assistance/advice/help would be greatly appreciated. I'm going
broke using my wife's Expedition as a commuter car.

Just guessing, I think that you disconnected some wire on the engine and
forgot to reconnect it, or you pinched it, or some such. Use your Factory
Service Manual and go back over the entire engine compartment electrical
system wiring, and make a visual check to be sure the harness is completely
connected everywhere, is not pinched, etc.

Also, have you checked the fuse box to make sure there's no blown fuses?

Ted

 

[Dave]

Just guessing, I think that you disconnected some wire on the engine and
forgot to reconnect it, or you pinched it, or some such. Use your Factory
Service Manual and go back over the entire engine compartment electrical
system wiring, and make a visual check to be sure the harness is completely
connected everywhere, is not pinched, etc.

Also, have you checked the fuse box to make sure there's no blown fuses?

Thanks for the reply, Ted. No blown fuses (I checked them all). I
only disconnected a single wire when working on the belts - the
connector between the main harness and the fan. I've been all over
the engine compartmewnt and can find no loose connectors. I suppose
it's possibnle that I may have pulled something loose while changing
the battery (it's pretty tight in there). It appears that the battery
has only 2 positive leads - one to the distribution center and the
other directly to the starter. I've got power at both places.

-dave

 

[Steve m...]

Sounds like something else died while working on it and letting it sit.
Maybe the crank sensor. With no spark it can be a lot of electronic stuff.

Steve m...

 

[Dave]

Follow Up:

I can start the car by bypassing the ASD relay. I do have to be
careful, because it floods easily (a LOUD backfire in my small
enclosed garage is quite frightening, believe me).

I understand that this relay is operated by the PCM; and from what I
understand is not permitted to close if the PCM does not receive a
signal from either the crankshaft position sensor or the camshaft
position sensor. THee may be other factors involved (anyone?)...

I don't know how to test either sensor, and I don't want to just
replace them only to find out later that I didn't need to. I'm
getting close to just bypassing the ASD relay, and carefully driving
it to the local Chrysler dealer.

I'd really rather not give up, now that I can start the engine.

-dave