Hello,
I am woriking on a Hyundai Elantra with 1.6L engine and am stumped at this point. Here is the details! It will start with starting fluid only and die. I have checked the wiring for the fuel pump and all of which checks out fine and the pump will run when you apply 12 volts to the test port. The weird thing is when you apply the 12 volts to the test port it still doesn't start. The plugs are dry so this leads me to believe the injectors are not firing. Checked for voltage at each injector and there is 12 volts there, also checked the negative during cranking and it does pulse as it should. Also checked for the voltage 5v & 12v going to the crank sensor and it is good.
I have replaced the crank position sensor from one I pulled in salvage yard which I am not sure is good and also replaced the ECM. I am guessing that from what I am seeing the crank position sensor is bad. What would be the odds that I got a bad one from the yard? What else should I check that I am overlooking? This thing is driving me crazy and I have to figure it out.

 

if you have injector pulse, spark, and runs on ether, your fuel pump is dead. fuel pumps can run, but only spit a couple of pounds of pressure, when a car typically needs at least 30 or more psi to run. i put my money on the pump.

 

I might buy that but here is my only concern. The only time voltage is going to the fuel pump is after crank cycle for about 30 seconds. With this in mind leads me to believe it is before the pump that is causing the problem. Wish I had a fuel pressure gauge so I could rule that out cause it has been considered. Just don't want to go out a spend money on parts I don't need is all.

 

i work in a gmc/buick/ hyundia dealership, and teh hyundia techs said thats normal, voltage is only applied to teh pump during cranking and for 30 seconds after that, if the car isnt started, just with teh key on.
im ase certified, as well, so im still 99% positive its the pump.

 

Is there any way I can test it for sure before I spend more money?

 

if you can score access to a fuel pressure test kit, youll need to attach a pressure gauge with a special banjo bolt to the top of the fuel filter. check this site out alldata, select "i am a then you can select your car from the list. select "engine", scroll down and select fuel pressure, itll tell you how to test for fuel pressure.

btw, keep this logon and password secret, its our account at my dealership.

 

mnstrmech,
Thank you! I will have to track down a fuel pressure gauge to fit. My only concern is that the only time I see voltage at the pump is after the key is returned from the start position. There is no power at the pump when the key is initially turned on or while in the start position. The only time voltage is there is in the run position after a crank cycle. Seems to me that voltage should be there some other times. I am far from an expert but don't want to become the infamous part swapper type of mechanic if you know what I mean. Again I appreciate your help and you definetly give me some more ideas to look for. Will keep you posted of my progress and also to make this thread worth while for someone else.
P.S Sent you a PM

 

Okay! Finally got a fuel pressure gauge and found out I have between 40 - 50 psi which is within spec. Not sure what this leaves besides the crank position sensor and fuel injectors. Is the proper procedure for testing the injectors by checking for voltage on 1 pin then for pimn 2 hook a test light on the positve of the battery and touching the negative pin of the injector and the light flashes? If this is the case I have to believe my problem is bad injectors or maybe not enough engine compression.
I know there is a couple of cylinders that have only 80psi right know. The reason for the low compression is cause the valves are new and since the engine hasn't ran yet they haven't seated all the way. But got to believe if it starts on starting fluid it should run on its own. What else am I overlooking here because I am losing my mind on this car?

 

Well finally figured this thing out. Turns out there are 3 injectors not spraying a drop of fuel. Now I have to figure out how to fix them. Just dropped them in carb cleaner for the night to see what happens. Figured if it don;t fix them it will kill them either way right where I started. Pretty sure their just dirty from sitting so long and probably all gummed up. New injectors for this thing run $100.00 a shot and don't feel like spending that kind of money just to turn around and sell the car. Anyway just wanted to give the feedback so incase anyone comes across the same issue they can learn from my mistake.
Thanks for all your help!