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Iv watched your videos and alot others and you seem like you know more than the other guys. So I have a question for you. My 1992 honda civic dx 1.5L stopped running. So I checked the fuel pressure and no fuel. My pump wasnt turning on either so I replaced the fuel pump and then tried the fuel pressure and nothing. So I tried to replace the main relay and still nothing. So I put my old relay back in and jumped the wires and I got fuel pressure. But only if I jump wires. This was tried with the new relay and old relay both same results and out comes so im taking the new relay back. Could you help me with why my car wont start?
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Also battery is good it tries to turn over but it acts like its not getting fuel. I also have gas in the car. Both are not the problem. Iv been beating my head because I dont know what is stopping the car from turning over.
I live in the US just so others know. Any help could make my day because yesterday I was ready to blow the car up
When you say jumping the pins, I’m assuming that is the contact side of the relay and not the control side. From that, you can conclude the fuel pump is OK when it gets power. What you need to do now is get a wiring diagram and see why the relay control side is not energizing. Could be a number of things (harness, connector, etc.). I assume your battery is OK, but that may need to be verified too since low battery output can cause strange problems.
This pic is a functional diagram of the main relay:
As you can see, the 2nd relay runs the fuel pump, and is turned on and off by the ignition switch. Can you hear if the pump runs for 2 seconds when the key is turned to the on position? If it does not, then there is a likelihood your ignition switch has gone bad. You can test this with a voltmeter by placing the negative (black) test lead on a known good ground and the positive (red) test lead on the main relay ‘ignition switch’ terminal. When you turn the key on you should read battery voltage (~12.5v). If you read zero volts, or less than battery voltage, the ignition switch has gone bad.
As a side note, to minimize confusion, ‘turning over’ refers to the engine actually rotating when the starter engages. It appears that this is happening, from your description, so your engine is turning over, it is just failing to run, which is referred to as a ‘cranking-no start’ condition. If it didn’t turn over, it would be a ‘no-crank-no-start’ condition.
The car is acting like it isnt getting fuel. When I jump pins in the main relay everything acts normal and gets ready to start and then it acts like the fuel isnt pumping. Iv had guy tell me to check the fuel pressure and then when I told him that the pump wouldnt turn on unless I jumped the main relay he then said it could be the ECM. I also had a guy at work tell me the timing belt could of slipped a tooth but that didnt sound right to me. The only time the car attampts to turn all the way over to running is with the jump throught the main relay and fuel forced into the injectors. The battery is also in good condition and trys to crank it. And the car trys to turn over but its acting like there isnt any fire. We have checked all fuses under the hood and the steering column also checked the plugs for spark. Nothing is adding up but a possible bad ECM. But I dont want to go buy a new one for $250+ if thats not the problem.
This scannerdanner video may be worth a view:
https://www.youtube.com/watch?v=QVxOQTSPyGY
What pins are you jumping to get the fuel pump to run?
It’s going to take some time with a VOM and a wiring diagram to rule out things. I agree with cap269, I would be looking at the igntion switch first. If that is not supplying power, the ecm will not wake up.
[quote=”ziggy41″ post=137182] Nothing is adding up but a possible bad ECM. But I dont want to go buy a new one for $250+ if thats not the problem.[/quote]
It most likely is NOT the problem. Please check your ignition switch, I am nearly certain that is your issue, it is also a very common issue. It’s easy to test (I gave you one method already), and they are inexpensive and simple to replace. The computer should always be the LAST thing to look at after everything else has been conclusively proven to not be the problem, otherwise the problem will still exist with a new computer.Hello 🙂
Here you have wiring for fuel pump.. See if you have Control, 12+ on pin2 ign on. And see if ecu Control ground too pin1.Ok I will check the ignition switch and get back to you. Iv been busy with trying to keep my job and get this car running and so far im stressing. I also want to thank everyone for inputs. I will be back on after I find out first thing. I hope it is the ignition switch not waking up the ECM and causing the fuel pump to not come on and the injectors to not push the fuel the last step. Like I said ill keep you all informed. Im short on cash due to bills so I wasnt getting the ECM anytime soon.
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