Steps needed to diagnose injectors :
Safety first . Be careful around engine compartment . Avoid moving parts and electrical parts that might shock you . Wear safety glasses and gloves .
Read all steps first . If your primary concern is injectors , then this diagnose will help . It is not necessary for there to be fuel pressure in the fuel lines since it is not the fuel pump or pressure that determines when the injectors open .
1 - Multimeter - Turn car off . Disconnect injector electrical connector and measure the resistance of the injector by placing multimeter to read ohms . Resistance varies by make and model . Average is 15 ohms for some GM models . Refer to a Haynes or Chilton manual for specific resistance value . If it passes resistance test that means that the electrical portion of the injector is ok .
2 - Noid light (available for rental at some auto parts stores including Advance Auto Parts ) - Disable coil(s) so car won't start by accident . Disconnect electrical connector to injector . Connect noid light to electrical connector . Crank ( not start ) engine using key switch (not a remote starter ) and look to see that the noid light flashes/lights up steadly . If it lights up then the connector is carrying voltage to injector . If it didn't light up the wires might have a short or computer is defective . Check the all fuses , relays , and engine codes ( if any ) before determining a short or computer is At Fault .
3 - Stethoscope/screwdriver - Leave the coil(s) diabled . If the injector is at least getting voltage ( step 2 ) then you can perform the third and most important test . Recconect the electrical connector to the injector . Have a friend Crank ( not start ) the engine using key switch ( not remote starter ) while you place the stethoscope against injector and listen for a clicking sound . This is the sound of injector opening . If you do not have a stethoscope , $14 at Sears , then place a long screwdriver against injector and listen through handle (avoid coming in contract with engine , specially electrical and moving parts ) . If you don't hear any sound coming from injector then it is failing to open and this means the injector is BAD .
when the hall effect and ignition module are good, the injectors and coil no work maybe this sensor is bad
pull the fuel injectors out and disconnect all electronics but one and put a plastic bottel on it now run the starter, if it is a nice mist you are ok, if it sprays then they are bad.
if you have standard injectors .you use an ohmmeter. to test for the ohm resistance
bad spark, bad gas, bad emissions controls, bad injectors...take your pick.
you have bad orings, wrong size, orings or you broke the other injectors or the their orings
timming is off bad plugs & wires bad injectors
Your check engine light should come on. You will have poor performance from the engine, no get up and go.
If two injectors have failed it is more than likely that the other injectors could fail. I would replace all the injectors, or at least inspect them for possible failure
Check the fuel injectors . one or more are bad or going bad.
Replace you ignition module, It controls both spark and power to the injectors. You can have spark but the module may be bad and not giving power to the injectors and the vehicle will not run.
Switch the electrical connections between the two injectors and see if the same one is still bad or if the problem switched to the other one. If the same one is bad, you have a bad injector.
Injectors could be bad
could be bad injectors
bad injectors (01-04) injectors are warrantied for 7 years 200k miles because of this problem.
A bad ingnition module, Are a bad computer.
Bad fuel line? Bad fuel filter? Bad fuel tank? Bad throttle body? Bad injectors?
GM throttle body injectors can be visually seen while operating. Remove the air cleaner assembly to expose the injectors. With the engine runningat an idle, they should have a nice umbrella shaped spray of fuel coming out. If one is dripping instead of spraying, it is probably bad. If one is dry, try swapping connectors with the other to see if the condition stays the same or moves over to the other injector.
Bad crank sensor could do that.
rough idle,execsive smoke from exhaust ,low power could all be symptoms of bad injectors . also check the delivery pump pressure it could also cause the same symptoms
I had a similar problem with one of my cars. It it's case there were 3 bad fuel injectors. I replaced the bad fuel injectors and it has done fine since then.
bad fuel injectors, bad timing, bad spark plugs and wires, clogged catalytic converter.
Bad as in dirty would simply supply unfiltered fuel to the injectors resulting in misfiring,hard starting and uneven and generally bad acceleration.Bad as in faulty could lead to fuel starvation,motor won't start, rev,cut out etc. no, supply unfiltered gas to the injectors? its a restriction, meaning no or very little gas to injectors, low or no fuel pressure
Either the "O" rings are bad where the injectors go into the cylinder head or the electrical connector on the injector is leaking.
Possible reasons the fuel injectors are not working: Faulty ECM (engine control module, computer) Faulty fuel injector(s). Fuel injectors clogged. Insufficient fuel pressure. Bad Ground. Faulty wiring otherwise.
Need to know what engine and what year and if it's gasoline or diesel to answer that. Some gasoline injectors are held in place by the fuel rail.