Need experience tech help with my car not getting spark or fuel

[Jag1980]

Here's the deal from the beginning..

I drove my car to the store just fine.
Went shopping, came back to my car and it wont start. After the 12 try it finally starts, so I shut it off and start it again twice and it's running great.

Drive to another store and go shopping, come back to start the car same thing, wont start.. Took about 15 times to get it to start. Drove it home and everything was great. The next day I get in, try to start the car and nothing happens.. Tried 50 times and no start.

Now the trouble shooting begins.

I changed the fuel pump relay, I changed the fuel pump, and I have replaced the ECU and still the same problem.

I get no spark.
I get no power to the fuel pump.
I checked all fuses that I can visually check.
My neighbor check it out for me who is a Master Tech and after checking everything he says it about 85% sure it probably the ECU.
Replaced that but still the same problem.

Now something that controls the Fuel pump power and the spark plugs in not working, but I have no idea what it could be or how to check. It must be a part that controls both of these systems together I'm thinking.

Can anyone help me please? My car has been stuck for over a month.

[discnik]

Could you provide model, engine size and year please.

[Jag1980]

I forgot sorry

1998 Elantra GLS 1.8L Automatic

[discnik]

You said that you get no power to the fuel pump.
You tested for voltage at the fuel pump ?

Have you checked for injector pulse at the injectors electrical connectors ?
You can use a test light and two paper clips, a paper clip in each port of the connector and the test light hook between them. Crank the engine and see if the test light pulses.

Possibility is the crank position sensor. Cam position sensor, and Mass Air Flow sensor, also ECM control relay.

Can you identify the location of the ECM relay and feel if it is energizing when you attempt to start the vehicle ?

I know on some vehicles if you disconnect the MAF the engine will perform normally because of the PCM default.

I still have not found test procedures for the Crank & Cam position sensors. I will keep looking.

Do you have a "Check Engine" light ?
Have you had a scan done on the vehicle just because the "Check Engine " light is not on does not mean that there are not codes stored in memory.

Some things to start with.

[Jag1980]

I get no engine codes or check engine light and nothing in memory.


All voltage to the Fuel Pump is correct except for the main power Yellow wire has no power. I tested the fuse box where the Fuel Pump Relay plugs into and that checks good.

I checked the Voltage to the Fuel injectors and everything is good. I don't think a pulse check was done.

I hear mechanical noise coming from the upper part of the engine, above the manifold. It's some electrical cylinder thing, not sure what it is. It's about 2" diameter and 4" or so long? Not sure what it is.
Probably has nothing to do with anything with this issue, but I thought I would mention it.

I don't think that there is a ECM relay on this car.
Some cars have this to protect the ECU from getting damaged? this car I think does not have one. Unless I'm thinking of something else. If there was, I think I would have already checked that in the beginning since that would probably be cheaper then replacing the ECU

Thank you for your help, very much appreciated. I am really stuck on this and not sure what to do next?

Let me know what you think I should do after everything I mentioned above.

I think it might be one of those sensors you mentioned, I remember when I belonged to the SCCoA I read allot about people cars having some of these symptoms and this is usually what there problem was.

Thank you

[discnik]

Check your Private Messaages. Lets start with fuel.

[Jag1980]

Thanks for the info.

I get voltage to all wires but not the yellow wire.
I did hook up a power wire to the pump and the pump works.
But, even with the pump going, I still have no spark..

So there is something that controls both the fuel and spark that is not working.

Crankshaft sensor maybe?

[discnik]

See if you can locate the "Engine Control" relay and see if there is power at the white/red wire. Check the diagram. That wire also supplies power to the injectors. Take a 194 light bulb, straighten out the filament wires and plug it into the injector connector. Crank engine and see if blinks. Repeat for each injector. The relay also supplies power to the cam sensor the red/white wire.

Check the diagram, the Crank sensor is tied into that with the ground. Try checking grounds for corrosion and cleanliness.

Possibly the Engine Control relay is bad.

Let me know.

[Jag1980]

This car doesn't have a Engine Control relay, I checked
That's why I had to replace the ECU and not the relay.
I heard that some cars will have this relay to protect the computer, but this car doesn't have it.
The injectors do get 12 volts, I checked each one and they all have power.

[discnik]

Does the vehicle have a security system ?

[Jag1980]

Nope

[shorod]

Originally Posted by Jag1980

This car doesn't have a Engine Control relay, I checked
That's why I had to replace the ECU and not the relay.
I heard that some cars will have this relay to protect the computer, but this car doesn't have it.
The injectors do get 12 volts, I checked each one and they all have power.

According to the wiring diagram for your car, there is an ECM relay. It and the fuel pump relay get power from the 20-amp fusible link in the engine compartment relay center. The ECM relay coil is triggered by a ground pulse to pin 27 at the ECM.

-Rod

[Jag1980]

Interesting.. Now I'm wondering how I determined that there was not one in my car. When trouble shooting with my neighbor, I think this is what we found out. I really don't remember, I will talk to him about this later.

I do get power to the Injectors, but should I do the light bulb test to see if I do have a flashing light when trying to start the car?

What image below is the one I should be checking or could be the problem?
Seems simple, but I'm having a problem figuring out which one we are talking about that I should be checking..

Picture 1, 2 or 3?

Image 3 looks like it is pointing at the fuel pump relay.?

[shorod]

I don't have the wiring diagram in front of me, but the ECM relay I was referring to is probably the ECM Control Relay shown in the first figure.

When you turn the key to the "Run" position with the engine off, the bulb test should illuminate the Check Engine light for a few seconds, then the light should extinguish as part of the bulb test.

-Rod

[shorod]

According to the wiring diagram, battery voltage is supplied to the ECM for "memory power" via a 10-amp fuse in the engine compartment relay and fuse box, labeled "B/Alarm" and provides constant power to terminal 26 of the ECM, a red/black wire. The PCM should provide a ground to the ECM Control Relay coil from ECM terminal 27 (black/red wire) which in turn provides battery power to ECM terminal 54 (red/white wire). The white/red wire to the ECM Control relay, as well as the fuel pump relay, should be hot at all times via the 20-amp fusible link B in the Engine Compartment Relay and Fuse Box.

Check these voltages with key on and with key in Run position.

For what it's worth, the red/white wire from the ECM Control Relay also provides power to the fuel injectors, the idle speed control servo, and the Mass Air Flow sensor.

Oh, another thing to try since this seems to be somewhat intermittant would be to put the car in neutral and try to start it. If that works reliably, then the transmission range switch is likely faulty.

-Rod