Mitsubishi Mirage

mitsubishi
mirage

#1

My friend has a 1995 Mitsubishi Mirage that he bought. It is a 1.5 automatic. It will crank and run with ether put to the intake. We replaced the fuel pump and fuel pump relay. It is getting gas to the injectors. What else could it be?


#2

Are the injectors functioning?


#3

Yes the injectors are working.


#4

Would the fuel pressure regulator cause it to not run?


#5

@sandymarie28

“My friend has a 1995 Mitsubishi Mirage that he bought. It is a 1.5 automatic.”

Was this vehicle parked for an extended period of time? Was this vehicle working properly when purchased or was it bought “as is” and not running?

I ask this because I’m wondering if it is injecting something other than fresh gas, like stale gas or water.

How are you determining that the injectors are working properly? What did you do to test that?
CSA


#6

Thanks. It was bought as is. The tank was flushed. It was not running when bought. He pulled the injectors out of the head while I turned they key a d gas purged. :blush:


#7

@sandymarie28

Good. That should help some folks attempting to help you.
Sorry, I should have included another question…

“We replaced the fuel pump and fuel pump relay. It is getting gas to the injectors.”

…These parts were replaced because prior to their replacement, injectors were pulled, and when you turned the key, no gas purged? Is that correct?

I want to know if this was a "controlled experiment."
In other words, I need to know that injection was tested both before and after and the new parts were installed to fix a seemingly obvious problem, no fuel delivery.

Or…

…was no prior testing done and the fuel system was cleaned and the parts were replaced?

Also, do you know why it was parked, originally, because it quit running or for other reasons? Was it running fine before it sat for an extended time?

Diagnosing and fixing a vehicle purchased in non-running condition can be challenging, even more so online!
CSA


#8

I trust you confirmed that the injectors were getting fuel, but wonder if you confirmed that they were firing properly. A problem with the Crank Position sensor could cause dysfunction of the injectors.

Valve timing might also be good to check. The '95 Mitsu Mirage uses a timing belt, and that might have jumped a tooth or two, throwing the valve timing off.


#9

Yes they were tested before. No purge before the new parts. And no we do not know why the car was parked. The man said he thought it needed a fuel pump.


#10

Thank you. We will try the timing tomorrow!


#11

So it starts right up and runs ok w/ether sprayed into the air intake, but won’t start or run at all without the ether? And you’ve visually confirmed gasoline is being injected during cranking? By pulling the injectors and observing them spraying gas? … hmm … that’s very puzzling. You’d think it would at least pop and run a little at least without the ether. Even if the fuel injectors weren’t doing their job perfectly. It doesn’t seem likely this is an ignition system problem or valve problem or compression problem. And injector timing isn’t that critical to at least get an engine to start and run.

Here’s some ideas anyway, besides the excellent ones above.

  • Injectors are spraying way too much and flooding the engine.
  • Injectors are spraying way to little and the lean mixture won’t allow the engine to start.

For the first, flooding, try starting it a couple times. Then disable the fuel pump, hold the accel pedal all the way to the floor, and see if it will start and run briefly. If so, that confirms a likely flooding problem. For the second, injectors spray ok but too lean, a fuel rail pressure test is probably the next step. If you have no way to do that, and you have the kind of fuel system with the pressure regulator up near the fuel rail, at least visually look at the vacuum hose which connects to the fuel pressure regulator and make sure there is no gasoline at all in it when you remove it temporarily from the fuel pressure regulator.

Also make sure what’s coming out of the injectors is gas and not a water/gas mixture. HOw I do that is spray some into a test tube, and wait overnight to see if it is separating into layers. If so, there’s water in the gas. If there’s no layers, it is still possible that all there is is water. You can figure out a way to differentiate between water and gas I presume.

BTW: Anytime you are working with gasoline, be extra careful. No smoking, no sparks, and the most important thing, do the work outside and away from buildings, and have a great big fire extinguisher right there ready to use if necessary. Best of luck.


#12

The timing is fine. Thank you so much. I am reading this to him now.


#13

Ok guys. He needs to remove the harmonic balancer to get to the crank position sensor and check the timing. He cannot get the bolt loose. Is there a special tool needed? He tried a torque wrench and an air impact gun. No luck. He also said when this car is running he will never work on one again. Lol. :joy::cold_sweat::raised_hands:


#14

The problem isn’t likely the ignition timing, b/c if that was off it wouldn’t run w/ether either.

The crank pulley bolt is quite difficult to get off. The engine turns while you try to turn the bolt. Mechanics use beefy air powered impact wrenches to do it. They take advantage of Newton’s “for every action there’s an equal and opposite reaction” idea. You remember Newton, right? The 18th science dude? I’ve done it by rigging a way to hold the pulley still, then use a 1/2 drive breaker bar / socket to loosen the bolt.

Like I say, this doesn’t seem like an ignition timing problem so there’s no need to remove that bolt in the first place in my way of thinking. If you think the ignition timing is off, suggest to run the engine on ether instead. You can probably get it to run long enough to check the timing with a timing light.


#15

Put a long breaker bar with the socket on the pulley bolt, wedge it into the frame somewhere, then hit the starter for a second. It will knock the bolt loose.

But, take the four small bolts out first and just pull on the pulley to see if it comes off. I had a Mitsubishi that I could not get the bolt off, turns out it wasn’t a bolt, just a hex head molded into the end of the crankshaft. I don’t think the 1.5Liter was this way but the 1.4 was. Could change a timing belt on the 1.4 in about 15 minutes.