INTERMITTENT STARTING. HELP PLEASE. WILL RUN FINE ON DAY NOT THE NEXT. on 2000 Mercury Villager

I have replaced about $400.00 so far.My wife will drive the kids to school one day and the next day the motor will turn over but will not fire up and that afternoon fires right up. I have replaced the dist.pluggs,wires and fuel pump and fuel pressuse reg. weard. I think that this is electrical.I noticed that the dash light will dim when driving.I can't trust this van and my wife needs to be able to trust it.

by in Decatur, MS on February 06, 2013
4 answers 5 comments
ANSWER by on February 06, 2013
When it wont start check for spark at the plugs!! If spark ok, good and hot, then it must be fuel related. Also it would be nice to have a fuel pressure test gauge hooked up at that time! Any codes? May have a crank sensor problem. If it aint getting spark, forget about fuel!!!!!!
ANSWER by on February 06, 2013
on my gmc I had a crack in the plastic top of distributor. I changed that and about a week later it started again. My son in law came by that evening and we were standing in front as my daughter cranked it. The coil powerpack started arcing a spark to metal next to it. We replaced coil pack 25 bucks from auto salvage yard. Do not forget to cake on electrical connection gel on engine side of coil pack, it prevents engine heat from wearing it out pre maturely. That was three years ago...solved my problem.
COMMENT by on February 06, 2013
Does not have a coil pack. Coil is in the distributor which has been replaced as stated. Good thought though.
COMMENT by on February 06, 2013
You may be right and of course I agree with Wetry as that is the terminalogy that my father passed down to us.Make sure you got good fire. In the old days they used to say if your dash lights dim or flicker check alternator and clean battery cables. There is a draw somewhere. On newer stuff electrical sometimes gives me a headache. So I do what I know and before I spend the big money I ask alot of questions like you are doing now.
ANSWER by on February 07, 2013
ck voltage at fuel pump or poss inertia switch is shorted or has burn't wiring.
COMMENT by on February 07, 2013
inertia switch? that is to the left of the drivers legg?
COMMENT by on February 07, 2013
its by the drivers outside of left leg according to all data
ANSWER by on February 07, 2013
What have you replaced so far?
COMMENT by on February 07, 2013
distributer,plugs,plug wires, fuel pressure reg., and fuel pump/filter.