I tested it with a noid light, it dosent light up while cranking. it has fire, fuel pump is working, fuel filter is new and in the right flow direction. is there a relay or fuse for the fuel injection?
1990 jeep wrangler yj 2.5l 4cyl throttle body injection
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If you have fuel coming out of the lines when you are cranking the engine then your fuel pump is working. You should only get a small burst of fuel when you first turn the key on and then nothing while the key is on, the ECU only tells the fuel pump to turn on when cranking and when it can see cam and crank sensor signals while the engine is running. The small burst of fuel you may or may not have experienced is only to prime the fuel rails. To test your injectors, you can buy what is called a "noid" light. They have them at most stores that have a good tool/automotive section, such as sears. You unplug one injector with the engine off, plug the noid light into the injector connector (harness side going to injector). Then start or crank the engine over and see if you can see the light pulse on and of very fast. You may need two people due to limited visibility while cranking the engine. Repeat this for the rest of the injectors. If you have an "ohm" meter, you can ohm check the injectors by disconnecting each one and touching the pins inside the connector cavity on each injector. The ohm reading should read between 5-20 ohms. I hope this info helps!
Check for spark on the side not firing. If there is spark, the injectors on the right side may have a problem in the wiring to them. Older multi port injection systems used a "bank fired" approach: all the injector grounds on one bank splice together before they go into the computer to be pulsed.
All of the injectors have a steady voltage applied to them when the key is on. The same color wire to all injectors is the power wire, it is a fused circuit, the fuse is in the power distribution box, and is hot in run or start. When the computer internally grounds the injectors, pulse occurs and fuel is sprayed out. Check if the right side has power to the injectors with key on, use a voltmeter or test light. To test an injector circuit, purchase a cheap "noid light" from a parts store. You plug it into an injector connector, then crank the engine over. If the noid light is blinking, the power and ground circuit is good for that injector.
Are you certain that the pump is on when the no start occurs? Do you hear it turn on with key on, not start, when the engine won't fire? It should turn on for 2 seconds to pressurize the line to the injectors. If you could, check fuel pressure when the no start occurs.
If it is the injectors, buy a cheap "noid light" to check the injector circuit. Buy the one that fits your injector harness connectors. You pull off a connector to one injector and put the noid light in the connector. When cranking the engine over the noid light should be blinking-that is the pulse that fires the injectors. The injectors have battery voltage to them any time the key is on. When the ecm momentarily grounds the injector circuit (internally in the ecm), the injector is pulsed. If the noid light does not blink or even light up when cranking, the injector circuit has a problem in the power side or the ground side.
CHECK FOR INJECTOR PULSE IF YOU GO TO YOUR LOCAL AUTO ZONE OR ADVANCED AUTO PARTS ASK THEM FOR THE INJECTOR NOID LIGHT KIT GO HOME AND FIGURE OUT WICH NOID LIGHT FITS YOU PLUG IT INTO THE HARNESS SIDE WHEN YOU UNPLUG 1 OF THE FUEL INJECTORS THEN CRANK ENGINE IF LIGHT FLASHES THEN THE INJECTOR SHOULD BE OPENING IF ITS NOT INJECTOR IS BAD IF ITS NOT FLASHING THEN IT COULD BE A FUSE OR CAM OR CRANK SENSOR OR A BAD PCM OR FAULTY WIRING
FUEL INJECTOR NOT FIRING COULD BE FAULTY FUEL INJECTOR.HOOK A NOID TEST LIGHT TO FUEL INJECTOR ELECTRICAL CONNECTOR. CRANK THE ENGINE WATCH THE NOID TEST LIGHT SHOULD BE BLINKING WHILE ENGINE TURN OVER.IF TEST NOID LIGHT STEADY PCM FAULTY NOT FIRING THE FUEL INJECTOR.IF FUEL INJECTOR DONT BLINK OR LIGHT UP.YOU HAVE OPEN WIRING CIRCUIT TO THE FUEL INJECTOR CONNECTOR.
sounds like u got no injector pulse comin from ecm.we need to pull ecm codes an review them ,possible camshaft sensors faulty they usually provide reference pulses to ecm for injector firing or pulse.without this pulse ur injectors will never open up to let fuel enter combustion chamber. one way of checking pulse is to connect a noid light(small light bulb that plugs in injector pigtail to chek for power to injector and ur pulsing ground coming from ecm to injector) an test for a blinking light while cranking engine.
CHECK FUEL PUMP AND FUEL INJECTOR FUSE.IF FUSE IS GOOD.YOU NEED A NOID LIGHT TO CHECK TO SEE IF INJECTORS FIRING.YOU CAN BUY A NOID LIGHT AT ANY AUTO PARTS PLACES.WHAT YOU DO DISCONNECT FUEL INJECTOR CONNECTOR.HOOK NOID LIGHT TO CONNECTOR.CRANK ENGINE TO SEE IF NOID LIGHT BLINKS.IF YES INJECTORS FIRING.IF YOU GET STEADY LIGHT.PCM NOT WORKING NOT FIRING INJECTORS.IF YOU GET NO POWER OR LIGHT DONT WORK.YOU HAVE A WIRING PROBLEM.YOU NEED A HAYNES REPAIR MANUAL LOOK AT THE ELECTRICAL WIRE DIAGRAM.TO TRACE FAULTY WIRE.
You need to find out if you have enough fuel pressure, and if you have injector pulse. A noid light is a simple kind of test light that you can get at a parts house to test injector pulse. Unplug an injector and plug the noid light into the harness. Have someone crank the engine, if it flashes then your injectors are firing. Check all the fuses under the hood. You should have 55 to 60 psi fuel pressure.
Have you got a noid light to test that you have an injector pulse while cranking?other vehicle noids will work as long as they can be plugged into your injector plug.Also make sure you have sufficient fuel pressure.Make sure the fuel system has been correctly bled to remove any potential air locks in the fuel rail/injectors