Question1993 Oldsmobile Bravda 4.3 vortec engine code W
Intial problem was car ran fine cold once it got hot would sputter backifire and then die. No start till it cooled off. Took it to dealer for diagnostic. Mechanic said could be computer or bad ground. Throwing tps (replaced it), MAP (replaced it), and O2 sensor codes.
Fuel Pressure test 60 psi Leak down occurs only while sitting for a half hour. Fuel pressure while running is about 50 lbs, needle does bounce.
Took it home. replaced computer. Car started same problem.
Took ingnition coil off tested when warm failed test replaced coil. Also put in new plugs (plugs looked good no oil no fuel dry light brown looking just like any other used plug I replaced.) wires and distribtor. No backfire no hard start but when driving between 25 and 35 mph hesitates and flutters!
Checked AIC Motor replaced missing O ring. Still problems exists!
Mostly flutters and hesitates and has even stalled out once or twice but at least restarts right away. Does not hard Start when dead cold or at normal operating temp. Hard start say when coolant is about 130 degrees. notice last drive could feel a slight backfire but very intermittant just did it once.
I did notice my temp gauge fluctuates goes up say 260 and the drops 195. Checked coolant level low. Small leak at water pump gasket. Fixed that That problem solved.
EGR valve was recently replaced. Used gasket with screen to prevent carbon holding plunger open. Kept old one it was held open with hunk of carbon. Soaked in GM top end cleaner and clean thoroughly. At least have a spare now.
When going up hill the d*mn thing surges backs off surges backs off.
1 Year ago replaced spider injector and nut kit. Nut kit lines were bad replaced injectors while had it open.
Pulled air vain to check for washing no signs of washing.
Uuugh! any ideas before I jump off the local bridge? FYI no troubles codes just flashes code 12 when I try to check to see if any codes now being shown. (it would be okay to post this question on board.)
AnswerHI BILL.LOL YES FIND THAT BRIDGE.I WILL TELL YOU BILL GREAT JOB WITH YOUR EXPLANATION AND YOUR DIAGNOSTICS.AND THIS IS A VERY COMPLICATED PROBLEM.CHECK FOR VAC LEAK ...FUEL PRESSURE SHOULD MAINTAIN 60 PSI.SURGING NOT NORMAL FOR THIS PRESSURE FLUXATION THOUGH..REALLY SHOULD REPLACE THOSE PLUG WIRES ...TRY THIS I WILL DO SOME DIGGING WITH MY BUDDY,S AT ASE AND GM SEE WHAT WE CAN FIND ...BILLYMAC
