Expert: Van - 8/24/2005

Question
I ran out of gas the other day, put the gas in and drove home. Later on the Blazer started hard but did start and ran rough for a few miles, later on still , it wouldn't start but tries too.
Strong spark, fuel filter is clear, gas flows thru when disconnected, runs on starter fluid for a few seconds, any ideas?  93 Blazer S10, 4.3 vortex 6, automatic 4x4....any ideas would be greatly appreciated.


Answer
Hi Steven,
One idea is the fuel pump.
It is intended to be cooled and lubricated by the fuel, but running out first heats it up, and then it runs dry for several seconds as it runs out. Not a good idea.
That pump may well be shot. The test is to connect a fuel pressure tester, and make sure it maintains about 13 PSI, during cranking and running. Just flowing gas is not enough...needs the 13.
Another possibility, assuming the pressure stays up, is a vacuum leak, or the EGR valve stuck open, which causes a huge vacuum leak.
The fuel pressure regulator could also be bad, which can be checked when the fuel tester is connected by squeezing the fuel return hose. If the pressure jumps way up, the regulator is bad.

Van