Q: no pulse on injector so not getting any gas

asked by on

not getting any gas in tbi put in new ecm but still no pulse
My car has an automatic transmission.

Three things are needed in order for the injector to spray fuel: 12 volts from the ECM fuse, ground from the ECM, and fuel pressure.

A simple check to test the injector and fuel pressure is to provide 12v and ground manually to the injector. You should hear it click and fuel should spray.

  • Warning: Be careful! Connect the injector side first to prevent a spark near a fuel spray.

You’ll have to cycle the key to prime the fuel system to do this more than once. If it does not spray, the problem is the injector or no fuel pressure. The injector should have around 1.3 ohms of resistance, if it is open or zero resistance, it is bad. The injector could be totally clogged as well. Fuel pressure should be 9 to 13 psi.

Check the wiring to the injector. You can check the positive side with a test light with the key on. If that is good you will need a noid light to check the negative pulse from the ECM. A test light will not work for this. Connect the noid light, and crank the engine. If it blinks, the wiring is good.

Did you check the spark on this engine? If there is no spark as well, the pick-up coil in the distributor is the most likely problem. This tells the ECM how fast the engine is turning. No pick-up coil input, no spark or injector pulse.

If the pick-up coil is the problem, you might be better off replacing the distributor. You have to disassemble the distributor to replace the coil. This can be difficult due to carbon and sludge baking on the the distributor shaft. Plus, you will get a new ignition control module as well. If you need assistance with this diagnoses and repair, reach out to a certified mechanic who will be able to replace your distributor and fuel injector if necessary.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. no pulse on injector so not getting any gas

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Engine knock in 1999 Chevy S-10

Sad but true--those things had the engine problems from the get-go. There used to be a website where people had class action suits for this car. They were suing GM, but I’ve noticed lately that the website's gone. I don't...

Q: broken crankshaft position sensor in block

Anything in the oil pan besides engine oil can cause severe damage to the engine. Pushing the remains of the crank sensor into the oil pan in hopes of it remaining there without causing damage is not advisable. Even the...

Q: Squealing noise under the hood

Hello there. I would try to make sure you turn off your A/C before you shut off the vehicle each time to see if the squeal goes away. The A/C may be trying to come on too soon before the...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...