What pulses injectors on 4.3 chevrolet 1500 throttle body injector
Getting 60# of fuel pressure at check point to intake, engine will crank and run if gas is poured into throttle body where injector is . have eleminated crank sensor , and ignition control module. what is outher suggestions that will not pulse injector. also checked all fueses and relays.
injector pulse is just controlled by the ecm or computer as some would say,u said u replaced wires? did u have a fire or melt wires? ecm is known to go bad on these,had a few of these trucks back in the day.
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Is that static pressure with key on, engine off? Or engine running pressure? Both should be near 60, usually key on, engine off pressure will be about 3 or 4 psi higher.
If it runs good after starting, the injector pulse must be good. No reason why starting and running pulse should be different. Only difference is when running, fuel pump power is kept on by the oil pressure switch, whereas in starting, the fuel pump relay keeps the pump on. Very unusual, let us know. Measure voltage at one of the injector's power wire with key on. It should be battery voltage or very close.
Check the fuel pressure with a fuel pressure gauge, when the truck stops See if the fuel injectors are getting a pulse with a niod light plugged into the harness "while cranking. motor". IF you get no pulses (NO flashing noid light) see if the security light is ON, on the dash. If the security system "kicks on" it will kill the pulses to the injectors.
What is liter size of engine? I don't know what relay you unplugged? Your fuel pressure sounds too high? If you have fuel return line, if it gets clogged, it could cause your fuel pressure to rise.
It is your fuel injector pulse width that controls fuel, If pressure is too high, it could cause a problem. Usually voltage to fuel injector, goes hot with engine cranking. The computer controls fuel injector ground.
injector pulse is conrolled by the computer and the spark is controlled by the inghtion mudule. even though the spark is happening the computer gets it's pulse information for the inghtion module too. So the ingtion module ( in the distrubutor ) can be bad on the injector circuit. If the fuel pressure is too low the fuel won't flow either. On Vortec engines the fuel pressure has to be 50 PSI or higher or it won't even start. The throttle body engines have to have 20. If not the fuel pumps hose inside the fuel tank may have a whole in it so the pressureized fuel from the pump just leaks back into the tank as the pump is in the tank. This happens alot. The injectores ( in the throttle boby) ( you did'nt mention the engine in yopurs) should have power on the one wire with the key on. The other wire should have a pulsing ground as the engine is cranked. To test this, connect a test light to the battery positive and the pointer to the wire and crank the engine if the light flashes the circuit is good and if the power is good this circuit is'nt the cause of your problem. On the throttle bobvy engines theirs a tap in the fuel line going to the the throttle bady near the back of the intake. a pressure gauge can be connected here to check the pressure. some don't have this fitting and you have to remove the fuel filter and put a tee connection wher the filter was and check the pressure there,. The fuel filter is inside the frame rail on the drivers side 1/2 way down the side on the truck, towards the center of the truck. Fuel pressure is a common problem.
Go to the parts store and get a noid light for your truck, plug it into the injector electrical and turn the engine over to see if there is electrical pulse, also check the fuel pressure, the pump needs 9-13 psi with the engine running. you know if there is no pulse your going to need to check the wireing first. let me know
What is your Fuel Pressure? Did you put the fuel filter on with the arrow pointing towards the engine? If so, then check to see if your fuel injectors are working. You will need to get a noid light set from your local parts store and plug them in to each individual fuel injector connector and get someone to turn the engine over while you watch the light. it should blink on and off. If not then you have a short in the wire or possibly a fuse blown. check the fuse compartment ( usually under the dash or under the hood) and find the fuel injector fuse and see if it is blown. if it is then something caused it to blow like a spike in amperage or a short to ground. check for broken wires on the fuel injector connectors and make sure they are securely connected. If it does blink on and off then they could be clogged, but normally if one is clogged or even not functioning, the truck will still start, it will just run rough. So im assuming something is not letting the fuel injectors pulse or your fuel pressure is too low to start an engine.
If hall effect switch was bad you wouldn't get any spark.What year 2.5L is this?Is this a 2 injector Throttle Body? The pink wire on top of injectors comes thru a 20Amp fuse controlled by the Ignition switch you should have battery voltage with key on The dark green and dark blue wires come from the pcm which are called injector drivers the drivers supply a pulsating ground if you crank the engine with a test light between either pink/dk green or pink/dk blue test light should flash dimmlythat would mean injectors are being driven but there isn't any fuel at the injector or the injectors are bad no pulse means either a bad computer ( which these drivers are known for going bad)or the computer isn't being commanded to fire the injectors.
Make sure that you're getting spark. A very common thing on these engines are coils going bad. If you can verify spark, check to make sure you have an injector pulse. As you rotate the engine, look inside of the throttle body and make sure that you see fuel pulsing into the engine. You can still have good pressure but you don't have an injector pulse, the fuel still cant get into the engine. You can use a test light as well to test for an injector pulse. One wire going to the injector will have constant power and the other will blink when the engie is rolled over. Does it start if you spray starting fluid into the throttle body? If it does, it's a fuel delivery problem. Again be sure you have spark from coil to distributor and plugs. You can remove the ignition module and take it to NAPA and they have a module tester. Have them test the module several times not just once. This will eliminate the possibilites of an intermitted problem. Let me know how it does. email@example.com