no juice to fuel pump after in-place rebuild 96 metro
04-20-2011, 05:37 PM
just finished putting in new rings, main and rod bearings and all new valves with an in-place rebuild. finished up everything, reconnected all the hoses and wires, nothing missing as far as i can tell but when i go to fire it up, holding my breath as always after a teardown, the engine cranks just fine but i could tell the fuel pump didn't start up. sure enough, no power to the pump measured at the connector under the back seat. fuses are fine, relay was switched with another identical one under the cover, still nothing. timing belt was put in properly, crank angle sensor looks good (no i didn't use the oil pan gasket) and even if there was some signal not going to the ecm, it seems like i should still hear the pump come on before cranking. it was all working fine before the rebuild, which i did for excessive smoke and bad valve in #3 cylinder. thought this car might have a fuel safety cutoff button somewhere but my manual doesn't indicate this. any ideas??? PS, 4 cylinder Throttle body injector, manual transmission. ALSO the fuel gauge is reading totally full but it was only at 1/3 tank when i started working on it, which i know was correct.
04-20-2011, 11:43 PM
well, as happens often enough i find myself answering my own problem. called my geo friend in new mexico and he said i may have missed the main ground on the intake manifold under the throttle body, four wires coming into two lugs bolted on the backside. said it was the main ground for lots of things including the ecm and nothing will run without it. thought i had gotten everything back on, no extra bolts sitting around but sure enough i found those wires dangling down in the dark shadows and with a mirror found the shiny spot where they had been attached. not a job for large hands but i found an appropriate bolt, got them on and started right up. of course it ran like shit because i had, in doing the valves, mashed two of the spark plug electrodes down onto their centers, but after fixing that it ran just fine. the misread on the fuel gauge was a good clue that a ground problem existed but on another car i had years ago a bad ground made the fuel gauge go to zero and the temp gauge to superhot; just a different way of wiring, i guess.
04-21-2011, 04:51 AM
Well done. I was thinking bad ground, but one nearer the tank. I should have known it was the big on on the manifold, usually is.
Automotive Network, Inc., Copyright ©2024