'87 Pathfinder V6--- Won't Fire!

[LincolnLove]

My 1987 pathfinder will no longer fire. It does turn over. I'm pretty sure no spark is getting to the distributor. Before the problem became permanent, the car was having trouble accelerating. I would push down the gas and the car would sputter and groan for a few miles before finally normalizing. The month prior to the problem we experienced a TON of rain, and that might have something to do with it?

 

Any ideas?

[Nismojunky]

when was thew last

[silverton]

have you replaced the cap and rotor? check for moisture on the inside of it.

[jj big shoe]

You probably have a bad coil. The sputter and groan you mentioned could be attributed to the coil getting weak which will cause the gas to only be partially ignited by the plugs. When that happens, the plugs get soaked and have a hard time firing at all. The only real way to test a coil (that I know of) would be to replace it with a known good one. You can test for spark, but you can't tell how hot the spark is. Pull the plugs and check them against this chart. It might give you a clue as to what's going on.

[Nytrosfinder]

This guy goes to my school and I recommended him here.

 

I will take a look when I have time.

[JamesRich]

You can test for spark, but you can't tell how hot the spark is.

 

It's easy to test your coil. Have someone else turn the key for you while you place your finger on the coil wire. If you feel nothing coil is bad. If you jump backwards a little coil is weak. If you pee on yourself coil is good!

James

 

Fine print: this is only a joke, don't try it!

[GoneHuntin]

You haven't broken a timing belt have you? If it breaks, or strips teeth off then the distributor won't turn and it doesn't fire. Remove the dist. cap and spin it over to see if it turns.

[Precise1]

The three basics: gas, spark and air.

 

We will assume it has air...

Check for rotor spin as above and examine the cap and rotor. If all is well, remove a spark plug boot and put an old spark plug in it (or pull it) and set it with the end against clean metal and have someone crank the motor. You should get a spark... Use JR's test, it works and isn't that bad!!

 

Has the fuel filter ever been changed/do you have fuel pressure? Can you hear the fuel pump??

 

Did you check the ECU codes to see if there are any faults? Write up is in the Garage/How To section.

 

B

[PATHRIDER]

If you do JR's test itll change to four basics

 

 

GAS

AIR

SPARK

ALCOHOL

 

Kidding aside, this might be helpful also

 

 

 

A. The most common cause of this symptom is a bad Crankshaft Position Sensor (CPS) inside the distributor.

 

PURPOSE:

The Crankshaft Position sensor, located in the distributor, monitors engine speed and piston position.

 

OPERATION:

When the rotor passes between the photo diodes and Light Emitting Diodes (LED) the slits in the rotor plate cut the light being transmitted to the photo diode from the LED. This generates rough-shaped pulses which are changed into ON/OFF signals by the wave forming circuit. The Engine Control Module (ECM) interprets these signals to calculate engine rpm and cylinder position.

Nissan Altima Dies, Won't Restart When Hot

Crankshaft Position Sensor

 

CONSTRUCTION:

The unit has a rotor plate and a wave forming circuit. The rotor plate has 360 slits for 1° signals and 4 slits for 180° signals. Photo diodes and light emitting diodes (LED's) are used for the wave forming circuit.

 

If there is oil in the distributor coming up past the shaft seal, then it is possible the oil may be filling in some of the slits and causing the engine to die.

 

However, it is much more likely the CPS itself is bad. Sometimes you can confirm this by letting the engine run for about 30 to 45 minutes with the hood closed, then tapping the side of the distributor with a small hammer. If the engine dies, you have a bad CPS for sure.

 

If it doesn't, the next time you drive it and it dies, check for spark at once. If there is no spark then you probably do have a bad CPS. The problem is if you check it when the engine is running normally, it will check out as good.

Edited March 2, 2010 by PATHRIDER

[LincolnLove]

The three basics: gas, spark and air.

 

We will assume it has air...

Check for rotor spin as above and examine the cap and rotor. If all is well, remove a spark plug boot and put an old spark plug in it (or pull it) and set it with the end against clean metal and have someone crank the motor. You should get a spark... Use JR's test, it works and isn't that bad!!

 

Has the fuel filter ever been changed/do you have fuel pressure? Can you hear the fuel pump??

 

Did you check the ECU codes to see if there are any faults? Write up is in the Garage/How To section.

 

B

[LincolnLove]

When the problem first occurred I took the wire extending from the coil and put the end of a screwdriver up to it and had someone turn the key. There was no spark. Does that mean the problem's somewhere before the distributor?

Edited March 3, 2010 by LincolnLove

[Precise1]

I think you need to test it against a grounded surface?? I always have, but if there still isn't any spark then check the dizzy cap, rotor and make sure the rotor spins.

 

B

[MY1PATH]

Ok heres a book on some tests you can do...

they are pretty simple but take a little time. Sometimes a transistor goes out and few people know about these or sometimes it doesn't do its job and it can damage the coil. Other times a coil with the wrong resistance can cause a transistor to fail. these are not very common problems in our rigs but it won't hurt to test them. When doing the transistor test make sure the key is turned on or you will not get any results. If the transistor checks out move on to the coil tests... After coil test #1 the FSM would tell you to move on but I reccomend you try test #2 (not in fsm)because its possible that the resitances and windings behave differantly under load.

 

 

Transistor test: (that finned thing next to the coil)Do this With a full battery or battery over 12v of charge(preferably 12.5 or higher) only testing black and blue wries going in and out.

 

Disconnect your coil and measure the voltage from the transitor plug (Black+ & Blue-) between the terminals you should get near 12v

Betwen the + terminal and battery/chasis ground you should also get near 12v.

Results below should help diagnose problem;

 

-12v is present only between + termial and battery/chasis ground then the transistor ground may be bad (check ground before transistor)

...-if ground before transistor is good but bad after the transistor then the transistor ground is bad (replace transistor)

-If 12v is present you transistor is good.(check wires to coil, plug wires, Cap, Cap Points, rotor, rotor button & Plug gap)

-If less than 12v is present(remember full battery) or no voltage is present then you should check the power going into the transistor.(below)

...-Battery voltage going in means transitor is bad and creating weak or ignition(replace transistor)

...-low voltage or no voltage means you have a wiring problem before the transitor creating weak or no ignition.(check more wires)

-If more than 12v is present than your transistor is bad and it may have damged your coil.(replace transitor and check coil)

 

were differant transistors used on the wd21 made by hanshin and by hitachi there may be specific tests for each or they might all test the same(with reguards to the other wires goning into the transistor). I did not post these tests because I dind't know

 

 

Coil Test:

 

inspect your coil for cracks or signs of abuse. If damged it can short out before it even reaches your spark plugs.

Test #1

 

-check for continuity between the 2 coil harness terminals(the thing on the meeter that beeps when you close a circut). if you have no continuity your primary winding is broken(replace coil)

-check for ohms (horse shoe) between the +/- termnals. It should be near 1 Ohm (stock coil)

...-if it is less (0-.7 Ohms) then the pimary winding is bad(replace coil)

...-if it is more* (over 1.5 ohms) secondary resistance may be too high (replace coil)

-check for ohms (horse shoe) between each(+/-) termnal and the plug wire side of the coil. It should be near 10 k Ohms (stock coil)

...-if it is less (0-.6 k Ohms) then the secondary winding is bad(replace coil)

...-if it is more* (over 10 k ohms) secondary resistance may be too high (replace coil)

 

*no reading on ohm meter indicates open circut or resistance too high to measure.

 

You can use a spare coil connector from a JY pathy to splice into the coil for testing...

setup for test #2:

1. connect coil+(black) to a true 12v source like the transitor or a GOOD battery chaged to 11.7-12.5(weak batteries may show voltage but will lack the ammount of current)
2. connect coil- (blue) to a wire with an exposed end (you will 'tap' this end to ground)
3. Install good plug wire into coil (solid core wires are ok for this test)and place the other end 1/32 to 1/16(0.031-0.060) from a common ground (not the transitor ground) Remeber spark plug gaps for the VG range from . 031-.045 (depending on year) so really trying to test beyond .055" pointless.

Test#2:

tap your exposed -wire to ground(not transitor ground) keeping it more than 1" from the end of coil plug wire. when you pull away it should spark and your plug wire near ground should spark too. Your plug wire spar should be blue or blue white when near the .031 range it may appear yellow or not at all if in the .055+ range.

If your coil wire cannot produce a blue spark it may have bad or shorted windings inside the coil (replace coil) If it cannot produce a spark it may have broken windings or shorted ground inside. In both cases a replacement is required.

Edited March 4, 2010 by MY1PATH