Starts and runs for 3 seconds

Tiny
ITSALLGOOD
  • MEMBER
  • 2002 HYUNDAI SANTA FE
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 100,322 MILES
Is there a sensor that the computer wants information from after the engine has been running for 3 seconds?
Friday, May 16th, 2008 AT 4:52 PM

44 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Check the fuel pressure and comeback with the pressure readings here is a guide to help

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Can I ask if the security light is flashing? That will cause this as well.

Please run down this guide and report back

Cheers
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Friday, May 16th, 2008 AT 5:27 PM
Tiny
ITSALLGOOD
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I'll get a guage and check it tomorrow. I did check the spark plugs today (they are new ) - black soot on all of them, one of them was gaped too small - reset the gap on all of them. Now the engine will run for exactly 4 seconds. Before regaping the plugs it would run for exactly 3 seconds. Took off the fuel rail with all four injectors - they all have a very nice spray. Bypassed fuel relay to keep the pump running - engine still dies at 4 seconds. Will check pressure next.
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Saturday, May 17th, 2008 AT 3:02 AM
Tiny
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Try to replace the plugs with new because fouled plugs will not work also it could be a plugged catalytic converter. Here is a guide to confirm the issue.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter
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Saturday, May 17th, 2008 AT 3:20 AM
Tiny
ITSALLGOOD
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Checked fuel pressure today. Pressure coming out of the pump: 75psi, pressure at the rail is 49 or 50psi - with or with out the vacuum hose plugged into the manifold port.
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Saturday, May 17th, 2008 AT 9:41 PM
Tiny
RASMATAZ
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That sounds okay, did you ever see if the security light was on?
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Sunday, May 18th, 2008 AT 6:15 AM
Tiny
ITSALLGOOD
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Ok, so the regulator should be keeping the pressure at 37. I'll try and find a new one on Monday. As I understand this, the fuel pressure is too high at the injectors and they are spraying too much fuel into the manifold making the sensors send crazy signals to the computer - then the computer is shutting everything down? And all this stuff takes exactly 3 seconds? (I did get it up to 4 seconds - but now it is back at 3).
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Sunday, May 18th, 2008 AT 1:38 PM
Tiny
ITSALLGOOD
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Installed new regulator yesterday, pressure at the rail was 43psi - engine would not start. Re-installed original regulator, pressure: 50psi - engine will not start.
It has spark, and it sounds like it will run, but when let the key off of the start position - engine stops.
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Tuesday, May 20th, 2008 AT 2:17 PM
Tiny
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Sounds like ignition circuit at ignition switch is open-No power to the igniton system-

Check the ignition failure sensor on rear of cylinder head.


https://www.2carpros.com/forum/automotive_pictures/12900_ign1_1.jpg

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Tuesday, May 20th, 2008 AT 3:33 PM
Tiny
ITSALLGOOD
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Did start today, ran for 3 seconds, one or two times it ran for 4 seconds. Will only actualy start and run 1 in 6 tries.
Checked the wires to the shut off switch:

Pink/Black is 12v with Key ON
Orange has 12v also with the Key On - voltage stays at 12 while the engine is running for 3 seconds - and stays at 12v while/and after the engine dies.
White has.10 with Key ON and 1.5-3v when it does run.
Black is Ground at all times.
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Tuesday, May 20th, 2008 AT 5:36 PM
Tiny
ITSALLGOOD
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Was just thinking, what are the odds that the new crank sensor is a bad one?
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Wednesday, May 21st, 2008 AT 3:43 PM
Tiny
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Its possible I get bad parts all the time.
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Wednesday, May 21st, 2008 AT 4:37 PM
Tiny
ITSALLGOOD
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What numbers should I be looking for?
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Wednesday, May 21st, 2008 AT 4:48 PM
Tiny
ITSALLGOOD
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If I put the Red lead from my volt meter to the Black wire on the cranksensor. And the Black lead from my meter on the Blue wire from the sensor I have a resistance of 6.88.
There is NO continuity to the Red wire on the sensor, and NO continuity between the Blue and Black wires on the sensor if I reverse the leads from the meter.
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Wednesday, May 21st, 2008 AT 5:50 PM
Tiny
RASMATAZ
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I've check for the resistances/ohms for the CPS no reference on it-try researching it. See below


https://www.2carpros.com/forum/automotive_pictures/12900_cps_7.jpg

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Wednesday, May 21st, 2008 AT 5:52 PM
Tiny
ITSALLGOOD
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Can't find specs anywhere? Maybe they are not ment to be tested? - Only replaced?
I ordered a new computer for the car, it should be here tomorrow. We'll see if that fixes anything.
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Friday, May 23rd, 2008 AT 3:13 AM
Tiny
ITSALLGOOD
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Just got the new computer today. I installed it in the car but it didn't fix anything. The engine still does exactly the same thing. I'm going to replace the crank sensor again, maybe that other one is a bad one out of the box.
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Thursday, May 29th, 2008 AT 12:49 PM
Tiny
KHLOW2008
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Hi itsallgood,

I am not sure about the EFI system used in this model, but a faulty MAP/MASS/Air Flow sensor would also cause such a problem. Air leaks in between these sensors are also possible causes.
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Monday, June 2nd, 2008 AT 11:32 AM
Tiny
ITSALLGOOD
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Hi!
Airflow meter was my first guess also, back when I first started playing with this thing. If I remember correctly, if I unpluged the electrical connector on the sensor, the engine would not even start. If I left the electric connector attached but took the whole assembly off of the rubber intake hose, it would start but still only run for the 3 seconds. I did check voltages going to the connector - and I concluded that was not the problem, and started looking somewhere else.
MAP sensor - that is one that I have not checked yet. Do you know the procedure?
I have concluded that the Fuel pressure regulator is bad - 50 psi at the rail, with the pump running, vacuum attached or not - pressure drops to 5psi as soon as the fuel pump stops. Will also replace the fuel rail - the center part where the small o ring seats is not round and it lookd that might be the reason for the pressure drop.
Also found that one of the coils is arking to the valve cover - under the boot - as it sits on top of the plug.
Was thinking that maybe the arking coil is tripping the missfire sensor and shutting the whole thing off?
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Tuesday, June 3rd, 2008 AT 3:37 AM
Tiny
KHLOW2008
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Hi itsallgood,

If it uses Air Flow, then there is no MAP.

What you mentioned about the coil is also possible.

High fuel pressure can also be due to clogged or pinched return hose apart from a defective fuel pressure regulator.
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Tuesday, June 3rd, 2008 AT 8:20 AM
Tiny
ITSALLGOOD
  • MEMBER
  • 37 POSTS
So today I just got my order from the dealer (to the tune of $575 ). I got a fuel rail, a fuel regulator, both coils and wires, ignition sensor, and MAP sensor. I installed it all on the engine and started it up. Guess what. Nothing new - it ran for exactly 3 seconds and died!

Was looking at the intake manifold - can't see exactly, but it almost looks like there is NO gasket between the intake manifold and the head? Seems to me that there should be one?
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Sunday, June 8th, 2008 AT 3:03 AM

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