Intermitent Fuel Problem

I COULD USE A WIZARD ABOUT NOW. HAVE 93 ASTRO AWD 4.3L W VIN
THE PROBLEM DISCRIBED BY CD SMALLEY A WHILE BACK FITS MINE TO THE TEE BESSIE STARTS FOR ALL OF 2 3 SECONDS AND DIES AFTER THAT IT JUST CRANKS AND NEVER FIRES AGAIN. CAUSE SHE WONT START I COLD TESTED IT BY GROUNDING OUT THE DATA LINK UNDER THE DASH TO GET THE TROUBLE CODES TROUBLE CADES SAY FUEL PUMP THIS IS WHERE IT GET FUN WE ALL READY REPLACED THE RELAY, FUEL FILTER, CHECKED THE FUSES, COULD HERE NOTHING FROM PUMP, NO TRACE OF FUEL NOT EVEN A SMELL FROM SHRADER VALVE WHEN DEPRESSURIZNG FUEL LINE GAVE UP HAD IT TOWED CAUSE I'M NOT EQUIP TO DO THE FUEL PUMP. THE TECH DROVE IT ALL OVER TOWN AFTER REPLACING PUMP NO PROBLEM. I PICKED IT UP DROVE IT ALL OVER TOWN CAME HOME AND PARKED IT FOR THE NIGHT NEXT MORNING WE'RE RIGHT BACK WHERE WE STARTED. START DIE CRANK WITH NO FIRE. ANY IDEAS I'M CLOSE TO VOTING FILLING HER WITH "00" BUCK :banghead:

I had the exact problem on our '95 Astro. Replaced fuel pump, relay, filter. Still had the problem. Went to the fuel pump relay socket (passenger side firewall above the HVAC unit) and looked closely at the pin locations in the receiving end of the relay connection, there was evidence of a corrosion residue likely from an incomplete contact at one pin location. Took a pair of needle nose pliers and gave a slight twist to the corresponding pin on the relay. Plugged the relay back into the socket and complete contact was then made. Have not had any trouble with the van continuing to run since. That was over a year ago.

David

Something to remember here on the operation of the fuel pump circuit is the method of diagnosis. The ECM diagnoses the fuel pump circuit by sending the signal from the ECM to the relay. Within seconds, the 12 volts going from the relay to the pump also answers the query from the ECM as to whether the relay responded to its signal. The same 12 volts sent to the pump is the relay's response to the ECM. If the circuit, whether the relay, socket, wiring, etc prevents the ECM from getting the signal, the code will be set. If the fuel pump also doesn't run, the troubleshooting becomes easier. You will need to backtrack to where the signal is sent to both places, and locate the source. One thing to remember... if the contacts or the connections are burned, locating the source is the only way to prevent a recurrence. Problems with the pump or connections can cause excessive current to be drawn from this circuit. This excessive current is the only way these connections can be damaged. Ray

Now THERE'S an answer ! That's some of the best troubleshooting logic i've seen posted on any forum. I love seeing not just a reply as to what to check, but also why. Nice post, good description of pump circuit operation.

Hi It's Fedup Problem Solve My Astro Basically A Mixed Up Mutt. It's A Custom Order Reject Late 93 With A Lot Of 94 Components On It. It Has Relay On The Fire Wall Located Between The Ecm-b Fuse And The Oil Switch. Gm Finally Admitted They Have A Reoccuring Problem With Water Leaking Under The Hood And Shorting Out The Connectors For The Relays.
The Connector Over Heated An Damaged The Two Of The Wires After The Snow Melted And The Van Dried I Was Able To Get It Started. I Found The Problem When I Tried To Remount The Relay And It Shut The Engine Off Like A Kill Switch. Replaced The Connector And A Good Wrap Job, Looks Like Problem Solved. Thanks For Your Imput Guys. Cuontyv You Might Want To Go Back And Check For Any Signs Of Water Leaking And Add A Barrier According To The Tech Who Couldn't Deny The Problem Existed After I Proved What Was Going On, With Out Fixing The Weather Stripping Or Putting Up A Barrier To Block The Water It Will Probably Happen Again. Thanks, Not So Fedup Now