The car hesitates to start.Then it goes to1200 RPM and slowlycomes back to 1000 RPM.Occasionally on start up it has back fired.Could it be a bad fuel regulator?It has no engine codes.I`m stumped.
2006-12-31 18:40:57 · 3 answers · asked by (A) 7 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
It could be a bad fuel regulator. What to check is take the vacuum hose off of it and run the motor to see if you have any gas leaking through the diaphram and up to the vacuum port, there were many of these that did this. Try this several times, especially when cold to eliminate it as a possibility. If this is not the problem, check for fuel pressure with a shop guage onto the rail at the motor. These motors should prime to around 60 psi and idle around 50 psi or so. If this checks okay, make sure fuel filter is new as this is a cheap component. Then I would suggest checking for maximum spark output to ALL spark plugs. Spark should be able to jump a large gap and be strong and consistent. If it is not, check all spark plugs and wires for corrosion or carbon tracking. If there is still a weak spark, you may have shorted coils inside the ignition coil which would have to be replaced. There is also a possibility of having a damaged mass air flow sensor problem. These sensors do get damaged by backfires. Check all the others and go from there.
2007-01-01 07:27:37 · answer #1 · answered by Deano 7 · 0⤊ 0⤋
Run some fuel injector cleaner through it... then change the fuel filter....
Remeber that the '00 will be heavily controlled by the ECM, so also check some sensors... esp. the oxygen (02) sensors and check for vacuum leaks.... a surge is too much than too little fuel... backfiring is too much fuel or too early of firing... so check the timing (it should be controlled by the ecu)...
Also what engine are you working on?
2007-01-01 03:35:15 · answer #2 · answered by Shikeagle 2 · 0⤊ 0⤋
Sometmes a massairflow sensor will act up and not set a code .ck also for vacum leak
2007-01-01 15:39:14 · answer #3 · answered by deltech 4 · 0⤊ 0⤋