I HAVE CHEVY 4.3 WILL NOT START
I HAVE A 98 CHEVY 1500 EX CAB THAT SHUT OFF I PUT IN A NEW FUEL
PUMP,PUT IN NEW SPIDER INJECTOR IM GETTING GAS TO INTAKE AND 60 PSI
PRESSURE. BUT WILL NOT CRANK UNLESS U GAS IN THROTTLE BODY THEN IT
RUN TILL GONE , RELAY REPLACED CAN ANY ONE HELP
sounds like a faulty TPS~
the tip off is when you've got to be extreme with the pedal to get it to run...that can only mean one thing~~~
Is that a vortex engine? if so DO NOT manually put gas in the throttle body. If you do and it backfires thru the intake even just a little you will be replacing the whole intake. They are made of plastic and will crack if it backfires. I learned this the hard way when my fuel pump went out on mine. Tested it the old school way by putting gas in throttle body. It cranked and backfired. Replaced the fuel pump and still would not crank. Inspected intake and saw where it had blasted plastic pieces all over because of the back fire. Replaced intake and it started right up.
Vortec. You will need to check the cam position sensor in the distributor. The PCM needs to see a certian RPM during engine cranking before it starts injecting fuel. If there is no signal there will be no fuel. This is very common on the older TBI engines, but does happen on the Vortec's too. (FYI for other people reading if you have a TBI it is called a pick-up coil (in the distributor) which it's signal is sent to the PCM via the ignition control module, the module usually fails on these).
Check The TPS to see if it is stuck in Clear Flood Mode . A voltage of 3.5v or over will cause a clear flood no start no fuel . reasons ?.... long time storage or using spray cleaners etc that gets into the TPS . .
