Mitsubishi: 95 turbo wont start, has gas and spark

On that year you have both a crank and cam angle sensor to deal with.

--
Todd Honea

"spoolingfool" <com> wrote in message
news:com... 
http://www.autoforumz.com/Mitsubishi-95-turbo-wont-start-gas-spark-ftopict108958.html 
http://www.autoforumz.com/eform.php?p=509700

Most all sensors can be tested in the car, just depends on the type of
sensor used.
Most distributors use an opto interrupter, and a disk with holes punched
in it at key points.
This type of sensor outputs 5 volts, depending on whether the light is
blocked or not by the disk. An analogue voltmeter may be able to detect
these voltages as the engine turns. On the other hand, if you remove
your spark plugs, turn the ignition key to "run" and rotate the engine
by hand, while monitoring the output of these sensors, these pulses
would appear very slowly, and the volt meter would be able to detect
then easily
Crank sensors (the kind that "crank walk" takes out) use a reluctance
pickup. Basicly a "gear tooth disk" rotates very close to a coil (the
sensor) and generates a low voltage in the coil as it passes by
(typically less than 1 volt). An ohm meter would measure whether the
sensor was open or not. These sensors are usually either good (have
some resistance) or are open, and have no resistance.
And just to be complete, temperature sensors are usually just resistors
that change value depending on the temperature around them. Use an
ohmmeter to measure them.

Even if you've pulled your ECU, after attempting to start the car, it
should have logged new errors.

I would have though that if you had spark and you had fuel, unless the
timing is out, you should have ignition. But I don't know much about
the turbo, it may require some other input. I believe both of the
sensors that "Nobody" mentioned, are located in the distributor, and are
the opto interrupter type.




Nobody U. Know wrote: 

On the 1G they were Hall optical. On the 2g they are electrical pickups.
Same effect, different method. The 95 and 96 are backwards on the cam sensor
(driver's side) versus all other years (passenger). The crank sensor is at
the crank.

If he has spark, I believe those sensors are working. The ECU wont send
spark without them. I would have said MAF, but that has a limp mode and
should start the car.

--
 

"spoolingfool" <com> wrote in message
news:com... 

If there's spark, the sensors are likely OK. If there's fuel pressure at the
rail, your fuel pump is OK. Hence MPI relay is probably OK too.

Its possible that the injectors are not getting power. On the 1G engines,
there's a set of large ceramic resistors mounted in an aluminium cage on the
firewall. 12V is supplied from the MPI relay, and then to the injectors. The
ECU grounds the circuit when each injector fires. Check that you have 12v on
the resistor block. If not, check the MPI relay behind the radio in the
center console.

Stewart DIBBS

Well, I wasn't sure about that engine / that year, anyway. I've worked
on my sons 1.8L (1991), and that's what I based my response on (the
factory service manual also covers the 2.0L engine). My other manual
(Chiltons 1990-1993 eclipse) shows the same thing.
The schematic definitely shows LED's and opto receptors, for the 1.8L,
2.0L non-turbo,and 2.0L turbo, and I can't find a "crank sensor"on the
crank, for these engines. However, the manual I'm using is 4 years
earlier than the poster's year, so I could definitely be wrong, about
his engine.

So if I understand your post "Nobody", this vehicle still has two
sensors, a crank position sensor mounted on the block, at the crank
(this would be a reluctance pickup (coil) then) and a TDC sensor off the
cam shaft, which would also be a "reluctance pickup" (that was a question)?

Not quiet sure what "hall optical" is though. I know what hall effect
is and I know what optical is, but haven't heard that term before.

I agree that the ECU will only fire the coil if the sensors report the
correct position of the crank. But the ECU doesn't know if the coils do
indeed fire when commanded to do so. If the timing is grossly wrong,
the engine won't start.

Are there two coils in this engine, and are they both firing. You can
measure the resistance between the outputs of the coil to see if they
have continuity. I believe cylinders 1 and 4 share the same coil, and 2
and 3 share the other coil. Resistance should be about 10 to 14 Kohms
(well in 1991 anyway).

I'm trying to keep my responses general, on this thread, as I am not
totally familiar with this specific engines electronics.



Nobody U. Know wrote: 

> So if I understand your post "Nobody", this vehicle still has two 
question)?

That is correct. The 95 DSM broke them into two sensors. Only on the 95-96
is it on the driver's side. All years (<95-, >97) it was on the passenger.
The 1G (<95) had only the CAM sensor as does the 91-92 3000GT/VR4. The 93+
GT has two, also. The vehicles with two sensors will not allow timing to be
adjusted.

You are also correct about the coil pairing. One half of the coil effects
two cylinders. Just because one is showing spark, doesn't mean the other is.

--
Todd Honea

"nirodac1" wrote: 

i only checked spark on one cylander, the closest to cam sprocket, i
will chech the others in a few minutes, is there anything other than
the ecu that makes the injectors work? i know i have pressure but i
dont think the injectors are pulsing because i dont smell any fuel, i
even took the return hose off the fuel pump and the fuel just cycles
through, i dont have a noid checker.... (i think there called) but i
will check to se if theres any voltage going to the injectors..... if
there is no voltage what can cause this? thanks for all the help all,
john

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