SimplyDiag Network Partner:
Garage Vitals

Santa Fe non starter

CpLuAg

Active member
Public Member
Monthly Member
>>> high pressure fuel is erratic/unsteady when graphed at cranking speed <<<

Thats possibly your issue right there.

Give me a call if you want a sounding board.
It could well be, I just wanna be sure that the next part that goes on this fixes it, if I had a day on it I reckon I’d probably get to the bottom of it.
I checked the waveform Hyundai have for the crank sensor thanks to Alldata (which I have to pay for myself as boss won’t) and the signal I get looks the same so I don’t think that’s the problem. I think as giving it fuel gets it going it is more likely a fuel issue as you suggest. I’ll rig the low pressure side gauge up again and get it running to make sure it’s maintaining pressure.
Can you think of anything else the ECU needs to see to trigger the injectors? The immobiliser light goes out but after about 20 seconds, not sure if that’s normal but as it goes out it’s probably ok, snap on read immobiliser and key is ok, borrowed Bosch KTS and wouldnt communicate with immobiliser. Thanks
 

Mark-C SDN

Modern cars, Its all wizardry and witchcraft.
Staff member
SDN Admin
Problem? Tag me please
Public Member
What is the fuel pressure whilst cranking?
 

ChrisEarls

Active member
Public Member
Monthly Member
Annual Member
It could well be, I just wanna be sure that the next part that goes on this fixes it, if I had a day on it I reckon I’d probably get to the bottom of it.
I checked the waveform Hyundai have for the crank sensor thanks to Alldata (which I have to pay for myself as boss won’t) and the signal I get looks the same so I don’t think that’s the problem. I think as giving it fuel gets it going it is more likely a fuel issue as you suggest. I’ll rig the low pressure side gauge up again and get it running to make sure it’s maintaining pressure.
Can you think of anything else the ECU needs to see to trigger the injectors? The immobiliser light goes out but after about 20 seconds, not sure if that’s normal but as it goes out it’s probably ok, snap on read immobiliser and key is ok, borrowed Bosch KTS and wouldnt communicate with immobiliser. Thanks
Immobiliser light does take a while to pop off on them usually when they start. Check your low pressure again rig your gauge up on the engine side of the filter as there is a little valve on top of the filter housing that gave trouble now and again. Have you a gauge to check high pressure? you can power up the regulator on the rail this will give you full fuel pressure you can read it in the live data. There is a bypass resistor tool for the plug going back to the ecu it won’t start without it but you can eliminate a lot from that test.
 

CpLuAg

Active member
Public Member
Monthly Member
Immobiliser light does take a while to pop off on them usually when they start. Check your low pressure again rig your gauge up on the engine side of the filter as there is a little valve on top of the filter housing that gave trouble now and again. Have you a gauge to check high pressure? you can power up the regulator on the rail this will give you full fuel pressure you can read it in the live data. There is a bypass resistor tool for the plug going back to the ecu it won’t start without it but you can eliminate a lot from that test.
Hi, I went through all my pictures and don’t appear to have the ones I took on fuel pressure anymore so I’ll get more.
Brilliant, I’ll disregard the immobiliser light. I don’t have a high pressure gauge.
I have a Delphi blanking plug kit for the metering valve which was used already to give the rail full pump pressure but I didn’t do the test myself so I don’t know the pressures.
I’ll focus on the fuel system, get some cranking pressures again and rig up the low pressure fuel gauge, get some readings when running before I have to put it outside again for afew more weeks no doubt. Thanks
 

CpLuAg

Active member
Public Member
Monthly Member
Right here we go again, as usual I have been given 40 mins on this, end of the day look busy kinda thing.
Anyway I’m sat in the car now, fully charged battery and fuel pressure is now steady at crank, I assume the erratic crank before was battery related. I’ve attached a picture, I calculate that to be 572 bar! Considering it will run happily at 321 bar at idle I’d say that’s high to crank at but would injectors not firing cause this perhaps?
duty on pressure valve is usually 19% but today 17%
Picture 1 at idle, 2 crank and 3 crank with more pids
 

Attachments

  • 2C8704CC-AE94-4F34-BF64-011A43DDF3E5.jpeg
    2C8704CC-AE94-4F34-BF64-011A43DDF3E5.jpeg
    2.8 MB · Views: 21
  • A3354F71-539E-4B92-AF5A-C719C7093A26.jpeg
    A3354F71-539E-4B92-AF5A-C719C7093A26.jpeg
    2.3 MB · Views: 16
  • EB6B770F-D2C2-48FE-A2D2-C4DCB882AAF3.jpeg
    EB6B770F-D2C2-48FE-A2D2-C4DCB882AAF3.jpeg
    3 MB · Views: 21

Mark-C SDN

Modern cars, Its all wizardry and witchcraft.
Staff member
SDN Admin
Problem? Tag me please
Public Member
Having a higher pressure during cranking opposed to idle is quite normal.
 

CpLuAg

Active member
Public Member
Monthly Member
Having a higher pressure during cranking opposed to idle is quite normal.
Thanks, would you say looking at the pressure, cranking speed and duty on the pressure valve that this is all normal?
There's something stopping this from starting and it must be something the ecu needs to see to fire the injectors, give it fuel and it runs, switch it off and immediately turn key back to crank and it refuses to start up until battery gives up. I’m trying hard to stop boss firing parts at it but I can’t tell him what it needs, I need time on it. I’ll call time on this thread I think and update if this ever gets fixed, thanks for all the help and advice so far everyone.
 

Ian d

Well-known member
Public Member
Annual Member
Hi did you do relative compression test to check for interference/drop outs?
 

CpLuAg

Active member
Public Member
Monthly Member
Hi, we don’t have an amp clamp, would it work the same if I use Volts at the 16 pin? Thanks
 

CpLuAg

Active member
Public Member
Monthly Member
Do you have a scope?
Hi you can do RC at battery then ac couple trace to see detail.
Just the snap on triton scope that I’ve been using.
Brilliant cheers, if I get a proper day on it I’ll do all these tests as best I can but I’m struggling to find the motivation when it’s being dragged in end of the day after countless other headaches, not feeling it at the moment so I’ll update when It’s fixed.
thanks again
 

Ian d

Well-known member
Public Member
Annual Member
HI been looking at cranking pressure on your screen shot, what is the unit for fuel pressure, my verus gives me either kpa or psi. yours shows 572557 what?
 

CpLuAg

Active member
Public Member
Monthly Member
Hi, thanks for the reply. I presume your in OEM data not EOBD
Hi. That’s right, there’s no expert mode option for this vehicle either but I get a reasonable amount of data, don’t get pump meter data but that’s been replaced. Thanks
 
SimplyDiag Network Partner:
Pichler Tools
Top