Jim Grant's Tech Tips
Jimmy, No Start After Tune-up
Q: My wife’s truck was running fine but
was having a hard time starting. It’s a ‘93 GMC Jimmy w/ 4.3 Vortec V-6.
I performed a standard tune up on it to include: cap and rotor, plugs
and wires, ignition coil, fuel and air filters. Now I can't get it to
start at all! I triple checked all connections, firing order, rotor placement
even bought a new battery. No warning lights were present before tune
up and no codes present when I performed the diagnostic check. I'm out
of ideas, please save my dignity!...Tracy
did you think for one minute that I wouldn’t have a field day with your
dilemma? Can I save your dignity? I wouldn’t want to be in your shoes
when your mother-inlaw finds out what you did. My mother in-law’s frying
pan can nail a guy at full run 200 yards outs. Gee, with this in mind
I have to help. Did it occur to you that maybe you did just fine performing
the tune-up? That the real problem fully manifested itself as you were
performing the tune-up? Yea that’s it manifestation. First, check for
spark at the coil. If present, is there spark at the end of the spark
plug wires? If there is no spark, back up until you find what you missed.
If there is spark then check the fuel system. If the fuel injection system
on your vehicle uses an injector and popit valves. If the fuel pressure
is too low, the popit valves will not open resulting in a no start condition.
Guess what your vehicle starts like when the fuel pressure is marginal?
Real hard. Spark, fuel and air in the right order and amount will make
your GMC run. In the meantime, hide the small frying pans, they just can’t
get the range as the big ones.