924Board.org

[AznDrgn]

Car has been running great the past couple days but today I went out and did some stuff it died on me. I went to see a house about half a mile from me and when I was leaving I started it up and started backing out of the driveway. I looked at the tach and it read 200rpm, I cut the stereo down and I could hear it. So I pulled over and checked under the hood to see if there was anything obvious like the distributor moved again or something, nothing. Car died a minute later.

I've got it at home now and I'm suspecting igntion problems because I can hear the fuel pump working and when I lift the air sensor plate I hear gas being injected. I took some reading on the coil and resistors and here they are: resistors got a reading of .4ohm and .6ohm, don't know what they are supposed to be but I think I heard that is about right. Next I took a primary coil reading from the positive and negative sides of the coil got 1.3 ohm supposed to be between 1 and 1.3 according to haynes manual so that's ok. The secondary reading from the tower to the 15 terminal was supposed to be 5.5 to 8 ohms I got an open line. After these results I'm assuming that the coil is shot just wanted to see if anyone else had an opinion on it.

Thanks

[Smoothie]

I get 3.38k ohms between the center and #15. It does look like you have a coil problem.

_________________
'82 931

[ This Message was edited by: smoothie on 2002-10-13 04:29 ]

[AznDrgn]

ok, thank you for checking that smoothie.

[Smoothie]

No sweat, glad to help - just wonder now if at 3.38k ohms mine's on its' way out. Time to get a spare and keep it handy...

[ This Message was edited by: Smoothie on 2002-10-13 04:29 ]

[AznDrgn]

I got a new coil and I decided to test it before I put it in and I get the same readings as the other coil. Smoothie when you tested from the center tower to 15 were you using a digital meter or analog? Both coils I have flash a number then goto open line. My digital meter can only go up to 2000 ohms so I'm figuring it goes to infinity. I also had my dad test against my brothers car and it has the same readings I have. So we're assuming that the coil is fine.

The new theory is the magnetic pickup coil inside the distributor is bad, I don't know how to test this but I'm gonna have to try it since I need the car tomorrow afternoon to go home. If anyone knows how to test the distributor pick up coil let me know.

Thanks

[Lizard]

check the cap and rotor and also the resistor

[Smoothie]

I used a digital multimeter and checked it twice - exactly 3.38 ohms both times.

A simple way to test the ignition and coil is to see how much of a gap the spark jumps. I have spark gap tester that I can take out tomorrow and see exactly how much of a gap my ignition will send a spark across, but I'm mentioning it now because you could get a close-enough test done by holding the metal piece at the end of a plug wire a specified distance from ground with the engine running. According to this tester, a 20Kv output coil should jump at least a 3/8" (1cm) gap. That should be the test gap for our cars. A 30Kv coil output should jump twice that (2cm) and a 40Kv output should jump 1" (2.5cm). The purpose of this test is to simulate conditions in a cylinder under compression (the spark is inhibited in the environment of a cylinder under compression). -And of course this test is done at the business end of the ignition system, so the coil and everything else gets tested at once. Just hold the wire with insulated pliers and don't ground "Mr. Johnson" to the fender by leaning in on the car.

[AznDrgn]

Problem is right now I have no spark so can't tell how far it jumps. Ordered a new distributor a few minutes ago and it'll be here in the morning costed $105 with a $50 core charge from Advanced Auto parts in case anyone else needs it. Hopefully I'll have a running car again tomorrow and i can get home. Wonder if it'll decide to quit on me on my 150mile drive.

[Smoothie]

What year and model is your car? Electronic or points ignition? Crank sensor or hall-effect sender built into the distributor?

[AznDrgn]

'78 924NA Hall effect and the rest of it is stock.

[wdb]

something as simple as the coil wire touching the body can cause a no start , wrap the coil wire in a piece of plastic trash bag where it touches any metal and give it a try . edit: I had the pickup coil that senses when the reluctor passes and triggers the coil, go bad in my mustang , caused a no start .

[ This Message was edited by: wdb on 2002-10-11 11:34 ]

[Smoothie]

I hate the hit 'n miss parts replacement routine. Tried scraping oxidation off the rotor and internal dist cap conductors? Hooked up the new coil for a try just in case?

[JPAB924]

To check the primary side of the coil use your ohmmeter and check between 1 and 15(positive and negative)you should get between 1-1.3 ohms. again using the ohmeter check the secondary side of the coil, terminal 1(neg) and the coil tower. This is where you made your mistake. You should get between 5.5- 8 ohms. If you get these readings, you should have a good coil.

an easy test to do to check to see if the control side of the coil(neg) is operating properly is to use a test light or voltmeter. Place the lead for the test light on the neg. batt. terminal and the test light on the #1 terminal. crank the engine while you are doing this and the light will flicker to indicate that the control side of the coil is doing its job...(the sensor in the distrib, or the ign control unit)If the light does not flicker, that means that there is a fault on the control side.

_________________
Joe Pabon nw Ind.
78 924 still working on it
77 924 stripped and gone
93 Ranger stx 4x4 (my mudder)

[ This Message was edited by: JPAB924 on 2002-10-11 14:29 ]

[ This Message was edited by: JPAB924 on 2002-10-11 14:30 ]

[JPAB924]

I bet if you check where the connector plugs into the distributor you will find that it is not plugged in all the way, seeing that you had a running car before this fiasco started.(this all started after you attempted the tune up) Make sure it snaps into place. I can almost bet that is your problem.....any takers?

[AznDrgn]

JPAB you are the man. Started to take out the distributor to change it when I pull the plug off the black boot over it moved and I found one of the tach wires was broken. Temporarily touched them and car started right up. Now I just need to replace the connectors, does it matter which wire goes where? both are yellow and they look identical.