Still no spark

[Barfyspitz]

With the distributor spinning you should see some AC voltage, around 0.333 or so. You can either remove the distributor and turn the rotor by hand, or last time I did it I left the distributor installed and used a remote starter switch to crank it over.

I then disconnected the pick up coil plug-in that runs from the wire harness into the distributor. I put my multimeter to the ohm setting, then ran the positive lead to both ends of the plug-in. First the gray then the black wire while the ground probe was held to the base of the distributor body just above the block. Both readings read ol.   Do any of these readings set off any alarms?

Thanks for the reply. Sorry it's been a while. I disconnected the plug from the ECu and tested voltage with the motor cranking cavity 4 showed .030v AC and cavity five showed .035 v AC

I have been following this but not chiming in because it looks like those responding have better suggestions than I would.  I have a question about the tests and specifically the test of the magnetic pickup on the distributor.  I did not see that you tested the AC signal coming out.  I saw the ground test, and others, also that you have tested the wiring, swapped coil, ecu, ballast resistor, etc.... which I assume since they are new and passing tests so far, means they are good.

[Barfyspitz]

Did you try jumping 12 volts to the coil? If you put 12 to the coil and it starts , you'd rule out the coil/dist. Correct?? Then just work your way back. So where do you live? As posted earlier , someone may be close.

I tried running a wire from the positive battery post to the positive coil terminal and nothing happened.

[Barfyspitz]

SEcond one from coil neg to dist pos wire , other dist wire to ground (if coil is working).

I'm sorry but I'm still unsure how this test is run. So you take a wire from the negative coil terminal and connected to which wire coming out of the distributor? I've got a gray wire and  a black wire. The gray goes to cavity four and the black goes to cavity five on the ECU plug

[Barfyspitz]

I checked to make sure the orange box was grounded by running my test bulb to the screw that goes through the Orange box and it lit up. I also had scratched the paint off around the mounting screw and touched it on the orange box as well and it lit up so I don't know if I need to run a ground strap or not because it looks like it's grounded.

[Barfyspitz]

One more thing... I disconnected the alternator and the voltage regulator to see if that would help because I've read that that might be a problem solver. No change. after putting a new battery on I tested the voltage on the ballast resistor when cranking.  The blue wire on the passenger side of the ballast resistor was showing 14 V? The blue and brown wire on the driver side was showing around 10?that can't be right Can it? I pulled the wires off the ballast resistor and did another ohms check on the ballast resistor showed 1ohm

[XH29N0G]

I suggest continuing to work through what Pete in NH suggested.  You checked the grounding of the ECU (I assume the test light was on the positive of the battery and touching the other end to the mounting screw completed that circuit because the ECU is properly grounded. 

Next would be something related to the (1) ECU, (2) the pick up or magnet on the distributor, or (3) the wiring. 

The sensor on the distributor is also a coil and you know you are getting a signal, but it may be weak.

Let me work through my understanding (apologies for restating to those who know - and if you do know - please correct any mistakes so I can edit) and see if this allows for the right test.

• The distributor spins the reluctor (a magnet with 8 bumps on it).  As each bump goes by the distributor sensor (pick up) it induces a field that turns into a weak electrical a/c signal that comes from the distributor.
  
• This signal goes to the ignition module (ECU) and if it registers with the ECU causes the ECU to ground the coil for a split second, causing a current to move through the primary windings of the coil, which induces a field around/in the secondary windings, and the secondary wirings then fire back to the distributor, which sends the spark to the right spark plug.
  

I think the fact that you are getting a signal means that the coil on the sensor is continuous, but the signal may still be too low to register with the ECU.  knowing the ohm reading through the sensor (as suggested by firefighter) could tell whether the sensor is OK and the low reading is related to the magnet.  (Earlier you set the distance between the reluctor magnet and sensor coil pick up.)

If I understand the system correctly, the ECU and the wiring should also be possible to test with the multimeter. 

• My guess is that you can test the wiring from the plug that goes to the ECU by tracing the wires and checking for continuity with the ohm meter setting. 
  
• My guess is that you can test whether the ECU is working by seeing if the pin that leads to the negative side of the coil goes to ground (on and off) when the engine is cranked over.  (this could be completely wrong thinking on my part but assumes what I have written above is correct).
  
• Also if the above is correct, I think you should be able to fire the coil by tapping (shorting) the negative   I am trying to describe something like that seen on the video at this link https://www.youtube.com/watch?v=H8mwAEQe6DM
  

If it were me, I would (1) test the resistance on the distributor sensor.  If that is OK, I would (2) test the coil to see if it fires as in the video.  If that is OK, (3) I would test the wires from the ECU to the coil for continuity.  If that is OK, I might (4) try figuring out how to test the ECU for a signal, but I would probably just go buy a second ECU or replacement reluctor and swap it in for a test.   For me the costs would be worth avoiding the future hassle.

[metallicareload99]

I suggest continuing to work through what Pete in NH suggested.  You checked the grounding of the ECU (I assume the test light was on the positive of the battery and touching the other end to the mounting screw completed that circuit because the ECU is properly grounded. 

Next would be something related to the (1) ECU, (2) the pick up or magnet on the distributor, or (3) the wiring. 

The sensor on the distributor is also a coil and you know you are getting a signal, but it may be weak.

Let me work through my understanding (apologies for restating to those who know - and if you do know - please correct any mistakes so I can edit) and see if this allows for the right test.

• The distributor spins the reluctor (a magnet with 8 bumps on it).  As each bump goes by the distributor sensor (pick up) it induces a field that turns into a weak electrical a/c signal that comes from the distributor.
  
• This signal goes to the ignition module (ECU) and if it registers with the ECU causes the ECU to ground the coil for a split second, causing a current to move through the primary windings of the coil, which induces a field around/in the secondary windings, and the secondary wirings then fire back to the distributor, which sends the spark to the right spark plug.
  

I think the fact that you are getting a signal means that the coil on the sensor is continuous, but the signal may still be too low to register with the ECU.  knowing the ohm reading through the sensor (as suggested by firefighter) could tell whether the sensor is OK and the low reading is related to the magnet.  (Earlier you set the distance between the reluctor magnet and sensor coil pick up.)

If I understand the system correctly, the ECU and the wiring should also be possible to test with the multimeter. 

• My guess is that you can test the wiring from the plug that goes to the ECU by tracing the wires and checking for continuity with the ohm meter setting. 
  
• My guess is that you can test whether the ECU is working by seeing if the pin that leads to the negative side of the coil goes to ground (on and off) when the engine is cranked over.  (this could be completely wrong thinking on my part but assumes what I have written above is correct).
  
• Also if the above is correct, I think you should be able to fire the coil by tapping (shorting) the negative   I am trying to describe something like that seen on the video at this link https://www.youtube.com/watch?v=H8mwAEQe6DM
  

If it were me, I would (1) test the resistance on the distributor sensor.  If that is OK, I would (2) test the coil to see if it fires as in the video.  If that is OK, (3) I would test the wires from the ECU to the coil for continuity.  If that is OK, I might (4) try figuring out how to test the ECU for a signal, but I would probably just go buy a second ECU or replacement reluctor and swap it in for a test.   For me the costs would be worth avoiding the future hassle.

I think you summed everything up perfectly

Your ballast resistor sounds like it's ok. Test the pickup in the distributor and the ignition coil, and if that checks out I think you have narrowed it down to the ECU, or the wiring to the ECU. Some auto parts stores can test the ECU, O'Reilly auto parts should have a tester. I have heard that the tester is a little eager to test "bad" when the ECU is ok. However, they can test a new one for you that should verify that it's good to go. Test it only a few times at most because it will overheat on the tester

[firefighter3931]

Have you checked the pickup ? Run a resistance test on the pickup and see what you've got. You should have around 300 ohms but the acceptable range is 150-900 

It sounds like there is no signal reaching the ECU 

To run the test :  Unplug the distributor and stick the multimeter probes on the orange and black pickup leads to get the ohms.


Ron

Thanks Ron. I disconnected the plug and ran my ohm meter into each of the wires, the gray and the black and got 279.2 ohms

Ok....the pickup checks out fine. One less thing to worry about. 

I'm thinking either the ECU is bad or the wiring to the ECU is bad....

Check the continuity on each wire in the ECU harness next. Could be a bad connectional at the terminal or a broken wire that's not visible inside the insulation. 



Ron

[Nacho-RT74]

sorry my friend I haven't replied emails anymore, but I have being REALLY busy latelly and with lot of personal issues

[Barfyspitz]

sorry my friend I haven't replied emails anymore, but I have being REALLY busy latelly and with lot of personal issues

Hey nacho! I hope you're well. Ive been getting some great advice in the meantime from fellow members. I will have to check the continuity as Ron has suggested from the coil plug to the ECU plug. I believe I checked them once before and it read a low number but I'll double check. I haven't  checked however, the continuity on the wires from the ECU plug to the coil. Should the reAdings be low?  If my multimeter reads ol does that mean the wire is broken?

[Barfyspitz]

I also have a tachometer wire to the negative post on the coil. Could a defect in that wire affect the spark issue?

[firefighter3931]

I also have a tachometer wire to the negative post on the coil. Could a defect in that wire affect the spark issue?

Yes, a defective tachometer can certainly affect the ignition system. Try removing the tach wire and see what happens. 

I will have to check the continuity as Ron has suggested from the coil plug to the ECU plug. I believe I checked them once before and it read a low number but I'll double check. I haven't  checked however, the continuity on the wires from the ECU plug to the coil. Should the reAdings be low?  If my multimeter reads ol does that mean the wire is broken?

When testing for continuity you want to see zero resistance ideally or a very low number. 


Several years back a buddy was having intermittent start issues. The pickup wires from the distributor going into the plug were hanging on by just a few stands. This happened at the track and I found it while fiddling with the harness plug moving the wires back and forth. Mad scramble as he was being called to the lanes for eliminations. Cut both plugs off and twisted the wires together with some electrical tape to seal it up and he ran for the rest of the w/e. New distributor ordered on Monday !  The one he had in there was toast anyway. 



Ron

[Nacho-RT74]

I will have to check the continuity as Ron has suggested from the coil plug to the ECU plug. I believe I checked them once before and it read a low number but I'll double check. I haven't  checked however, the continuity on the wires from the ECU plug to the coil. Should the reAdings be low?  If my multimeter reads ol does that mean the wire is broken?

That's one of the tests I told you on one of the mails.

Several years back a buddy was having intermittent start issues. The pickup wires from the distributor going into the plug were hanging on by just a few stands. This happened at the track and I found it while fiddling with the harness plug moving the wires back and forth. Mad scramble as he was being called to the lanes for eliminations. Cut both plugs off and twisted the wires together with some electrical tape to seal it update

BTDT

[Barfyspitz]

Hey guys I appreciate all the help. Sorry I've been so busy. It's been a while since I replied to your posts.  I ran some more test last night.  I ran another ohms test as nacho and Ron have suggested.I ran one test from the coil plug in to the ECU plug that goes to the distributor. The gray wire that goes from the coil pickup cavity four was reading .3 ohms. The black and white wire that runs to the cavity five was reading .4 ohms. The other test I ran  was from the ECU plug to the coil.  Cavity one which runs to the positive post on the coil was reading 1.0 ohms.   Cavity two which runs to the negative side of the coil was reading  .4 ohms. I don't know if these numbers sound right, but due to the fact that I didn't take pictures before I started unhooking wires I was going off memory. I could've sworn that I had both the cavity one and cavity two wires going to the positive post. But I could've been mistaken. I rewired  both cavity one and cavity two wires to my new ECU Orange box. I wonder if I burned up the ECU unit in the process. Therefore I ordered a cheap Napa ECU box to try. It's not an orange box but we'll see what happens. I'm hoping that's what is wrong with that.  Let me know if any readings I came up with sound wrong please. Thanks guys

[Barfyspitz]

I'm praying I can have it running by July when my son comes home from yuma airbase for my daughters wedding lol n

[flyinlow]

Sent 2 PM but they don't show in outbox. Did you get them?

[XH29N0G]

I'm praying I can have it running by July when my son comes home from yuma airbase for my daughters wedding lol n

We are too.   I think it has to be solvable, even after chasing it for so long.  I am hoping on the NAPA ECU.

[Barfyspitz]

Sent 2 PM but they don't show in outbox. Did you get them?

Yes I did man. Thank you. The napa ECU should be in today.

[firefighter3931]

If the wiring has checked out with the continuity test and the ballast, coil & distributor pickup are good then it has to be the ECU. 

Hoping you have a positive result ! 


Ron

[Barfyspitz]

Hi guys. Well this morning I hooked up the new ECU  after making one final check of the continuity. I checked for spark and it was there! It was orange not white or blue like I've read but I put the plug back into the head and it fired up!  It sounded so good hearing the general run again! My wife came running up to the garage in her towel dripping wet (she was in the shower when she heard it fired up)LOL!  She was hopping up-and-down just as excited as I was LOL. I want to thank all you guys for your help...nacho,  Ron, flying low, Xn29 Metallicareload and all the others that helped me. Thank you so much for working me through this. I really appreciate it!  In a way this was a blessing because I finally can say that I actually understand the ignition system!  I've learned so much and I actually know how to use my multimeter that I bought back in 2004 LOL. I believe when I hooked up the new orange box I rewired the coil wrong and burned it up.  I might take it for spin tonight! Thanks again you guys

[firefighter3931]

Great news !   

That's the thing about troubleshooting your own car....you learn a lot and this experience will make further diagnosing much easier should another problem crop up in the future. 

Nice work and way to go for not throwing in the towel. There's a solution for every problem....you just have to know how to find it and make the correction. 



Ron

[crj1968]

Awesome !!!   

[cdr]

 

[Barfyspitz]

Great news !   

That's the thing about troubleshooting your own car....you learn a lot and this experience will make further diagnosing much easier should another problem crop up in the future. 

Nice work and way to go for not throwing in the towel. There's a solution for every problem....you just have to know how to find it and make the correction. 


Thanks man. There was a lot of times I wondered if I would lol I'm gonna change the oil tonight.  Bought some valvoline vr1 20w50 racing lil. . Oreillys recommended it due to my flat tapper cam and the zinc. Would that be better than regular 10w40 valvoline for my 509 purpleshAft?  It's a low mileage motor with 11:1 compression. Has 75psi oil pressure when cold. Drops off when warm



Ron

[poppa]

[quote   I might take it for spin tonight! Thanks again you guys
[/quote]

You better! I'll take mine for a ride tonight too. Just to celebrate with you.