Mitsubishi Repair Questions? Ask a Mechanic for Answers ASAP
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)
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??
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?
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.