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Greg
Greg, Technician
Category: Mitsubishi
Satisfied Customers: 5586
Experience:  17 years shop owner, 27 year Import technician
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1999 Mitsubishi Mirage: engine idling from a cold start..restarted

Customer Question

Vehicle is 1999 Mitsubishi Mirage Dingo model GF-CQ2A LEHC 2 with a twin cam 4G15 Gasoline Direct Injection engine.
Problem is the engine shuts down after 12 minutes of engine idling from a cold start. Allowed to cool, engine can be restarted. Enabling electric radiator fan to run constantly, engine will then idle for 20 minutes from cold start before shutting down. Yet to test whether removing thermostat extends the idling time.
The temperature guage indicates normal temperature, so is there a heat sensor somewhere that is prematurely and falsely sensing an overheating problem? If so please some details and where it to be found.
Please detail any other causes that may produce the above problem.
Thanks
Submitted: 3 years ago.
Category: Mitsubishi
Expert:  Greg replied 3 years ago.
Hi welcome to JA.com.I will answer your question the best I can,

Is the check engine light ON.

It could be any of the following , best way to check this is when the car is running to have the MUT II connected and check the live data for the possibility as shown below.

Component check sequence
• Air intake system vacuum system- leaks
• Idle air control (IAC) valve
Throttle position TP) sensor
• Throttle valve/sticking/accelerator cable adjustment
Injectors
Crankshaft position (CKP) sensor
• volume air flow (VAF) sensor
Intake air temperature (IAT) sensor
Barometric pressure (BARO) sensor
Engine coolant temperature (ECT) sensor
Fuel pressure/fuel pressure regulator
Fuel pump/fuel pump relay/relay module
• Condition of fuel/Fuel filter
• Engine management system - connections/wiring
Engine control module (ECM)




Need further assistance Just ask.
Regards Greg
Greg, Technician
Category: Mitsubishi
Satisfied Customers: 5586
Experience: 17 years shop owner, 27 year Import technician
Greg and other Mitsubishi Specialists are ready to help you
Customer: replied 3 years ago.

I do not have access to a "mut II" so I'll just run some theories by you.

The check engine light does not illuminate when the fault occurs. It appears to be a fuel starvation problem as engine tries to fire when an immediate restart is tried. So guess the controlling computer has not shut down the ignition.

I have checked that the fuel pump relay is making the electric fuel pump work. Swapped it with like relays and I can hear it ticking at restart attempt. Tried running with petrol cap off in case fuel tank vacuum a problem.

When the fault is about to occur, switching to air-con on loads the engine makes engine "hunt" and then die. A thinng fuel air mix just prior to engine "death" perhaps ?

Just waiting a couple of minutes the engine can be restarted and will run for several minutes before stopping again. The 2 minutes seems to be little time for any sensor to

cool off and one would expect any sensor to have a much longer hystersis period (or time out period).

So I am suspecting a fuel blockage that restricts the fuel delivery to the point where the engine dies then some how allows enough fuel past during the short "cool down" period.

Can you tell me where the fuel filter is located ? There is also another sensor I can see through the branches of the inlet (but can not reach), can you tell me what this sensor is.

Any other suggestions??

Cheers

Charle

 

Expert:  Greg replied 3 years ago.
Hi Charle.

You need a fuel presser tester to see what the fuel pressure is to does sound like a fuel problem like you suspect yourself?

"There is also another sensor I can see through the branches of the inlet (but can not reach), can you tell me what this sensor is."

Is this sensor on the block middle area?

Fuel pressure should be 3bar 32 - 34 psi.

Fuel filter is in the engine bay just before the fuel injection rail

You have an intank fuel pump with a pre filter .

Regards Greg
Customer: replied 3 years ago.

Hi Greg

The bulky alloy inlet manifold fills the gap between the fire wall and obscures any view of the fuel injectors and the works below, but the sensor I see through the small gaps in the casting is in the middle block area.

The fuel lines arrive at bottom left of the engine bay. There are three pipes (guessing 2 delivery and 1 tank return) and they all connect directly (no filter in the lines) to what I had assumed to be the petrol pump. This is a cube of machined alloy about 2" wide flush with the top corner of the cylinder head (transmission end). This extends under the obscuring inlet manifold so I can not see what form it takes further in. It has a label with MD 362933 and ZEXEL on it aswell as a stamped serial number.

Is this part part of the fuel injection rail or another petrol pump? The inlet manifold would have to be removed to get to it.

I am thinking the intank fuel pump filter may be a good first option to check out as thinking back the vehicle has been hesitating at acceleration for some time now.

How would one measure the fuel pressure given the choice of the three pipes?

Cheers

Charlie

 

 

Expert:  Greg replied 3 years ago.
Can you get me a photo of this for me.

Greg
Customer: replied 3 years ago.

Hi Greg

Sorry for late response, been away installing extra earthquake monitoring recorders!

I have checked that the "in tank" fuel pump and filter are working OK. I am coming to the view that there is some temperature sensor (not the water temperature sensor),

some where that is prematurely signalling an over temperature condition to the controlling PC, which them shuts the engine off. The point at which it does this seems to be occurring sooner each test. So a degrading sensor seems likely.

As the only candidate sensor I can see requires a large amount of disassembly, I will get the local Mitsubishi Dealer to attach their MUT 11 up and diagnose the problem.

So I hope that has a good outcome. In the mean time I thankyou very much for you advice and interest.

Cheers

Charlie

Expert:  Greg replied 3 years ago.
Hi Charlie .

Good move using the Mut II, will be the best way to check this problem ,
If no codes are found they will have to check the live data for out of the ordinary readings
which can be over looked so give them all the info you can as with me .

Happy motoring Charlie .

Kind regards Greg

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