 1994 starting probs
My 94 Ranger 3.0 L sometimes will not start right away, if I wait 10-15 minutes it then usually starts with no problems and runs normal. This does not happen regularly, maybe once or twice a month, but has been going on for about 8 months. Recently it has gone dead on me while driving down the road, has happened 5-6 times and always within the first 5-8 minutes of driving. Once it restarts it runs fine again, this has happened about once a week for a couple of months now. Had the feul injectors cleaned, changed spark plugs and distributor cap. Check engine light came on with codes 327 (EGR Signal too low) and 543 (Fuel Pump open battery to ECA?) Mechanic suggested replacing distributor since the ignition module is most likely the problem and once it gets hot it will not start until it cools down, stated that new distributor will take care of starting problem along with spark knock.
These two codes mean exactly what? Are they the reason for the engine giving out? Mechanic wants to do more daignosis which means more money and am wondering what problems these two codes cause???? Mechanic could not explain it so I could properly understand......any help greatly appreciated... | 
