Delayed Ignition Cutoff Relay Wiring

[kupcar]

Hi All, I知 trying to track down a no spark issue in my 76 930. Upon inspection I found what appears to be a brown ground wire disconnected from somewhere. There is an open spade terminal on my relay 930.617.117.02. It looks like terminal 31. Does anyone have a wiring schematic or know if the ground goes to pin 31. I知 not an electrical expert by any means, so any help would be appreciated.

[flightlead404]

Year car?

The delayed action relay on an 86 is wired thusly:
30 - 2 x 2.5mm cross section red wires
S - 0.5mm red/white
L - 1.5mm cross section red/white
31 - 0.5mm cross section brown wire ground point MPXI which is inside the engine compartment left hand side, may be at the electrical panel

[kupcar]

Flightlead, thanks for the info. The car is a 1976 model year. That brown wire is connected to the ground bolt by the rear relay panel. Must have worked it’s way loose. Now to track down my no spark issue.

[Alan L]

Broken green trigger wire from dizzy? At the base, rear of dizzy.
Alan

[kupcar]

It maybe the distributor wire, I don’t know. Is there a procedure to test if it’s that wire? I’m certain I have no spark to the plugs. I do have a bench tested working 8 pin Permatune cdi box and a new coil. I think I need to verify I’m getting power to the cdi box first? There’s not a lot of info out there. I’ve been reading through old posts trying to figure out the testing process. Unfortunately I’m not an electrical guru. To complicate matters, it seems that the 76 930 has a different distributor wire than the later turbo which is NLA! If anyone has any ideas on the best way to pinpoint the problem, it be much appreciated.

[Alan L]

The green wire is a shielded 2 core cable. The two prongs at the dizzy end exit as two terminals at the plug under the CDI box. They are the two terminals (top and bottom) 2nd in from rt as looking at the plug terminals. You could try and see if a wire is broken (continuity).
Also if your coil is defective you will have no spark. Easiest test is to swap in a known coil, but there are ways to test them. You could just take it to an Auto elec shop and get them to test. Simple job for them.
The green wire is hard to get out - no room. You probably have to pull the dizzy to get the plug out. If you do; get the engine to Z1 and make sure the rotor is pointing to #1 firing - and indent mark on the dizzy body - at about 2 o'clock (take the cap off). Pull the dizzy, do not move the engine. Check wire and reinsert dizzy. It is a helical gear so you have to rotate it a bit before inserting back to get it to line up again when fully inserted. You will see it rotate as you push it home. Mark with a marker pen the base of your dizzy and the casing before removing. That way you just line the dizzy body with the marks to get your timing back to original.
Alan

[flightlead404]

I'd start from the basics.

1) make sure you're getting power out of the delayed action relay when ignition is in RUN and CRANK - 2 key positions to test.
2) check you're getting power out of the connection to the cdi
3) cdi should whine when it has power (true for permatune?)
4) check all your grounds
5) check the length of the green wire as much as sgreen wire can be reached it frequently becomes brittle and cracks
6) make sure connections from the cdi to the coil are correctly oriented
7) spark plug wires on the correct posts on dizzy
8) dizzy cap on properly
9) roto on properly - do you have a spare you can swap out? rotors fail

Green wire can be replaced by one from a 928 (longer and a cheaper wire, you'll need to trim) or something lead for an external wifi antenna. It is important to keep the correct orientation of core and shield correct the "zero crossing" of the reluctor is affected by this which can cause timing to drift at higher rpms if installed backwards.

[kupcar]

Thanks for everyone痴 guidance. I had a few minutes to remove some of the intake piping so I could get a better look at the wiring. With a test light I was able to see 12.8 volts to pin 30 on the delayed ignition cutoff relay. This was with the key turned to the run position. It also shows 12.8 volts in the off position. The three other pins showed no volts. I also had the cdi box disconnected for this test. I didn稚 have an extra set of hands to engage the starter and check for voltage on the pins. Does the relay allow current through the relay when the starter is engaged or should there be voltage at 2 pins when the key is turned to the on position? Not sure how it operates.

[Alan L]

You probably need the relevant bits of the factory manual (Chapt 28 - checking ignition system), including checking the CDI and green wire specs. tried to copy some pages for you - but beyond me. I am an IT twit. Maybe someone else can post the relevant stuff.
Alan

[kupcar]

Thanks Alan. Appreciate your efforts. I’ll get this. I will learn as I go.

[loganwhite]

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[Alan L]

Originally Posted by kupcar

Thanks Alan. Appreciate your efforts. I値l get this. I will learn as I go.

A systematic approach - as Flightlead suggests, is always best for ign/fuel issues. There is so much stuff inter connected. You can short cut it a bit by hitting on some common issues - as posted above. But if they fail you really need to start at the beginning and work thru. In which case you need that bit of the Manual.
Regards
Alan

[flightlead404]

Assuming the 76 is pretty much the same as the 86 (ass you me?) pin 30 is connected to the battery via the 14 pin connector on the firewall (pin 14), the alternator B lead, and starter motor solenoid. It is unfused and hot all the time, be careful. On my car this connector on the relay has 2 x 2.5mm red leads. The other is power to the 3 fuse block in the engine compartment, (unfused, hot all the time!),

Pin S (s for switched?) gets switched power from fuse 7(?) in the frunk when the key is in run or crank position. Did you check that fuse? Check your diag or the label in the fuse box, owners manual etc, power at the fuse? Power at pin S?

[kupcar]

Ok Fellas, here’s the latest. I’m pretty sure I don’t have power to my cdi box. I finally had an assistant for a few minutes that could crank the starter while I tested the plug leads. The 8 pin plug has no voltage to any of the pins while cranking. Also with the cdi box disconnected, I tested the pins on the delayed ignition cutoff relay. Pin 30 had voltage the entire time, no other pins had voltage when cranking the engine. I’m pretty sure the 14 pin connector has power. Anyone know the electrical flow of the system? I’m sure it’s been discussed somewhere. I’ll try to search history. I think progress is being made! Thanks everyone, the troubleshooting continues!!!

[dap930]

I have attached a scan of the factory wiring diagram that shows delay relay. I hope this helps.

[flightlead404]

Sounds like you are not getting the switching power to pin S from the key/fuse box up front. You could try temporarily jumping pin 30 to pin L to try starting (or at least hear if the CDI box whines) indicating it has power.

If that works you know the CDI and wiring from pin L to the CDI works.

Then try jumping pin 30 to pin S and see if it energizes the relay and provides power to pin L. If that works you know the relay works.

Then work backwards, see if you have power at the correct fuse in your front fuse box when the key is turned.

[kupcar]

Thanks everyone. Here is the latest update. I ended up jumping the lead that had voltage to the delayed ignition cutoff relay to the red and white wire that was on the pin above. This brought power to the 8 pin plug. I hooked up the cd box and now I have spark! I’m still a bit confused, I must have a bad ignition switch? Shouldn’t I be getting power to the 8 pin plug when I turn the key to run? I’m very excited to get to this point. Thanks to everyone who has given their time and advice. Now, how do I proceed to fix the problem.

[flightlead404]

Originally Posted by kupcar

Thanks everyone. Here is the latest update. I ended up jumping the lead that had voltage to the delayed ignition cutoff relay to the red and white wire that was on the pin above. This brought power to the 8 pin plug. I hooked up the cd box and now I have spark! I知 still a bit confused, I must have a bad ignition switch? Shouldn稚 I be getting power to the 8 pin plug when I turn the key to run? I知 very excited to get to this point. Thanks to everyone who has given their time and advice. Now, how do I proceed to fix the problem.

ok so you jumpered the always on power to the cdi so now you know the cdi works.

I detailed some other steps in my previous note you need to take to determine where the fault lies.

[kupcar]

Flightlead, I spent a bit of time going through the front fuse panel. I cleaned terminals. I went through the fuses, one by one, and checked voltage for the particular circuit that it was labeled for. Things seemed to checkout. I didn’t really see a fuse that pertained to the cd box or anything to that sort. Any idea what it may be labeled as? Getting closer!!!

[flightlead404]

Do you have the factory workshop manuals or a wiring diagram for your car?

these are as essential a tool as a 10mm socket or a volt meter to work on your car. If you don't have them you need to get them.