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Discussion Starter #1
I have had a tech out to look at the car and he said it has a air problem.
The car wants to start then stops.He says its not a fuel problem?
I have just replaced injectors with new copper washers,checked turbo its ok,cleaned EGR with toothbrush and checked it across the battery and it works, MAF cleaned,fuel filter seems ok.
The return fuel from the injectors is just weeping out of the top when its turning over. Not sure if that is normal or not.

So I have hit the wall no more ideas can anyone help???????

Brad
 

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I have had a tech out to look at the car and he said it has a air problem.
Did you ask him to explain what the air problem is? Does he mean the engine can't draw air into the cylinders, or does he mean there is air in the fuel lines?

BJW said:
The car wants to start then stops.He says its not a fuel problem?
Have you tried using another fuel source to confirm that? Given it a spray with easy start/start ya basterd to see if that gets it running?
 

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Discussion Starter #3
Yes he thought maybe cat blocked or turbo seized or possibly EGR.
No I haven't tried any spray yet. Where is the best place to spray it?
Thanks
Brad
 

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Discussion Starter #4
He checked codes but I think nothing of importance.
He did show me the laptop where it had a air % reading which he said should around 12% on a idle but when we try starting the reading jumps to 100% that's why I think he thought there was a blockage.
 

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Yes he thought maybe cat blocked or turbo seized or possibly EGR.
OK, so he was one of those "technicians" who just can't admit he doesn't have a clue.

BJW said:
Where is the best place to spray it?
There is a big hose that comes off the front of the intercooler and connects to a valve at the front of the engine. Disconnect that hose at the intercooler and spray the fluid into it.
 

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Discussion Starter #7
Well the spray worked it started but only if you spray as it cranks. If you stop spraying car stops.
I disabled glow etc.
Thanks
Brad
 

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Well the spray worked it started but only if you spray as it cranks. If you stop spraying car stops.
Well, that quick, simple test seems to have ruled out all the things the "tech" said could be causing the problem.
The engine will run on starting fluid so that suggests you have a fuel delivery problem. What I would do now is check the output of the fuel rail pressure sensor to see if enough pressure is building in the rail to allow the engine to start. Do you own a voltmeter?

Oh, and can you tell us what those unimportant trouble codes were that the tech found?
 

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Codes p0101 p0238 p0047 p0489
Could these codes have been logged by you disconnecting parts while trying to diagnose the fault? Did the tech manage to erase them?

On each end of the fuel rail there is an electrical component. One is the pressure control valve (2 terminal connector) and the other is the pressure sensor (3 terminal connector).
Disconnect the pressure sensor. Where the wires enter the connector there is usually a plastic clip on cover. You need to remove the cover so you can access the wires.
The center wire is the one carrying the pressure signal. You need to use a pin to back probe the center wire.
Now reconnect the sensor and attach your voltmeter to the pin so you can monitor the voltage with the sensor connected.
Switch the ignition on and you should get 0.5V on the meter. Now crank the engine and the voltage should increase as the fuel pump builds pressure in the rail.
The voltage needs to reach 1V before the PCM will start to inject fuel into the cylinders. If the voltage doesn't reach that value no fuel will be injected and the engine will not start.

BTW, I just realised you have another thread running where you said the engine would start but wouldn't continue to run. Is that still the case? The fact that the engine would start suggests there must be enough pressure in the rail for fuel to be injected.

Back probing Hyundai rail pressure sensor
 

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Discussion Starter #11
Not sure if the codes are from removing terminals but possible.
Also a have been taking the terminals on and off so I would think the codes would still show up.
The engine is still the same it wants to start but doesn't.
I not sure if its my imagination but if I remove the terminal on the fuel sensor/pressure control valve it seems the start sound turn over is a bit longer?
The one that I see a difference is the one on the end of the rail (left side standing in front of engine)
I will do the tests during the week if possible warm days near now just like Scotland.
 

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The other thread
 

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What were the results of the Tank Pump? And I'm curious about
fuel filter seems ok.
How was that tested?

Throwing this one out there, is it possible for the heater unit to leak air or crack and cause issues at the filter assembly? bad O-ring?

I came across someone with a no start after a filter change on the FD i30(suction fed HP Pump), primed normally by hand . End result was a filter housing swap fixed it, never found the actual cause but we were wondering if the housing had cracked.



 

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Discussion Starter #14
Well Gerard,
I have had a friend do a full scan and a few error codes came up. Then I connected everything hoses etc then cleared all codes tried starting then checked codes again it is came up CLEAR??? no faults but still wants to start but doesn't.
So now its not electrical it must be filter.
He noticed when we turned the car over the fuel pressure reading came up ok but was dropping pretty quick??
 

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I wish I knew more but that's kinda what I saw when I connected to that FD but I also do not fully understand how it all works. I think it'f there's an issue it may be that the pressure gets cut or the ECU won't let the engine fire if the pressure is not correct. But that was a suction fed pump. What you have is similar to my Sonata with an in tank pump, no hand primer.

There were no ECU related codes on that i30 either. Maybe the pressure from the filter to the inlet of the HP pump could be checked. This is out of my scope though, just threw that idea out there based on what recently happened with another car I tried to help with.
 

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Discussion Starter #16
Thanks Gerard 2
Yes could be pump,filter,injectors etc etc.
I have just in the last couple of days had sons(young) friend how works for Hyundai bring a scanner from work to scan which came up with codes that related to me unplugging things so he cleared all then we tried turning the car over a few times then did a scan and it came up GOOD no codes? but it wont start??
Brad
 
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