This is long story..After cleaning the engine
and doing an overhaul we encountered a no start
situation. It sounds like it's going to start
and turns over and we can hear explosions in
the trottle body.

We checked compression of the cylinders,
everything is good. Bought a new gas pump, it
has good gas pressure. Replaced ignition coil,
put in new spark plugs, New battery, new spark
cables, new distributor cap and new rotor. New
crank position sensor. The camshaft position
sensor was checked and everything looks good.

Have checked voltage and grounds from the PCM
(computer) and that splice everyone is talking
about that corrodes easily has been checked and
looks great.

My truck cranks but won't start. Two things I
have noticed are

1. Even though the coil is new and has a
resistance of 0.9-1.1 in the primary and 12.7
in the secondary (which are in the specs for my
truck).. We have an orange colored spark on the
coil and no spark at the spark plugs.

2. We checked the injectors. The pulses of
the injector tester are turning on every 3
seconds, but still it is not constant.
Could be because it does not start. We checked
for continuity to the computer and everything
is correct, but still no start.

Is the PCM (computer) going bad??

I need a guideline as to where else to check to
be completely sure the PCM is bad. I have
spend sooo much money on this truck, I don't
want to replace an expensive part and find out
it still doesn't fix the problem.

Any ideas?? Any info will be greatly
appreciated.

 

It may be helpful to know what year and motor you're working on.

The phrases "crank position sensor" and "camshaft position sensor" tells me it's a Magnum, so my first few comments (based on the TBI 3.9) I deleted, since it has neither *grins*

RwP

 

I'd replace the camshaft sensor anyway. Its cheap. It sounds as if the spark is not getting from the distributor to the plugs. Is it possible the timing chain is off by a tooth? The Magnums were built without a tensioner and the PCM can only make up for so much. I had a no start situation after doing an engine washing many decades ago. I learned to spray WD40 in the Cap and to make sure the wires have some or dielectric grease on them whenever I install them now.

 

Yes. It's a 95 dodge Dakota 3.9 6 cylinder. Any suggestions are appreciated. Thanks