1978 308 GTS. Owned since June 2019. Logistics 1. Basic set of Craftsman wrenches, sockets, torque wrenches, etc. Basic. 2. Quick-Jack 5000 3. 2.5 car garage 4. Steady stream of F-Chat and 308restoration.com knowledge from those who actually know wtf they're doing. 5. Beer Tasks completed 1. Fuel hoses 2. Oil changes (engine, transfer case, gearbox) to include engine oil filter. 3. Complete renovation of wheel wells and undercarriage. Scrub baby scrub. Current debacle 1. Car will not start after three months of good, reliable runs. 2. Good fuel flow. No spark. (My pilot checklist of fuel-spark-air) 3. I thought I had flooded and fouled the plugs so I replaced the plugs. Went to iridium based on 308restoration.com. Six hours....that front bank kicked my butt. Yes, I suck. 4. Checked and swapped fuses. Entire box looked great actually. 5. Checked distributor and cleaned. Looked very good, too. 6. Tested spark plugs (two of them). Nothing. So, I yanked the coil (original Magnetti-Marelli BZR202A) last night for testing. Advice, please, from the experts would be greatly appreciated. I am still too proud to trailer to a local shop for repair. Thank you. Dane Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Your ignition system seems heavily non-stock -- what do you have? Optical trigger, magnetic trigger, something else -- and is it all inside the distributor or do you have an external ignition ECU? And just one Magnetti-Marelli BZR202A coil firing all eight cylinders? The easiest first thing to do is confirm/deny if you've got +10~12V on terminal 15 of the coil during starter motor cranking
If you do have +10~12V on terminal 15 of the coil during starter motor cranking (but no spark) = puts the probability of the trouble in the aftermarket ignition system components or coil (assuming you've already confirmed the dist cap and rotor and wires are OK). You can also do some very simple resistance measurements on the coil itself (the "+" terminal is terminal 15, and the "-" terminal is terminal 1): Image Unavailable, Please Login The values in this picture may not be exact for that coil (i.e., I wouldn't freak out if the primary winding measured 3 ohms), but a primary coil resistance of 0 ohms, or some high value like hundreds or thousands of ohms, is evidence of failure. Same for the secondary winding -- should 10ish or a few 10s of KOhms (not low and not MOhms). If you don't have +10~12V on terminal 15 of the coil during starter motor cranking = puts the probability of the trouble in the fuseblock. Do you have the stock fuseblocks or something else? (This is one downside to installing a super-duper ignition system -- it uses more current so puts extra stress on the stock wiring/connections supplying that current.
I'll hold off until you tell us what in hell you have for an ignition system. Otherwise, my contribution will be "where is the distributor for bank 1?" Also, where is BZN?
Ok gents. Thank you for your help. The spark plug test photo may have been a misrepresentation. Attached are three additional photos. The "tach adaptor" is "mounted" in front of the left rear taillight. It certainly does not look stock! I refer you back to the thread title. I truly have no idea what to do except start replacing parts (coil, plug wires, etc). Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
It isn't The red box with the "MSD" is the aftermarket ignition ECU (and looks like an older one that is no longer available or has been updated to something a little different): https://www.holley.com/brands/msd/products/ignition/ignition_boxes/
Awesome. The label states MSD 6A. Looking at your link (thank you), the MSD 6201 (Digital 6A Ignition) is the closest in existence. Recommendations, please? Man, I'd pay for this advice. Thank you for now.
Already gave them in posts #3 and #5. If you pass all of that, then you'd need research if MSD has some sort of troubleshooting guide for your model and/or confirm all of the wiring is OK.
Upon learning from Steve's information and link, it appears I have a MSD Digital 6A ECU. BZN. Ahhh yes. Bozeman, Montana.
My neighbor has that MSD system in his old Ford somebody converted for him. He spent a weekend and could not get it started. He asked me to come and look. It took about 60 seconds to figure out that the pick up signal wire running from the distributor to the MSD box was broken and no spark was firing by the MSD box. That is all I got. For this kind of system, you have to have hands on it to chase down the problem.
Dane, I am going to put a programmable MSD system on my 308 so have done some testing and have an idea of how this was probably set up. Check the coil as described well by Steve above. If that tests ok then: First unplug the gray wire that comes out of the distributor. Test if any of those connections are short circuited to the body of the distributor. Then test if any of them are shorted to each other (the grey wire will probably be stiff and the insulation has possibly crumbled and failed— if so cut it off next to the VR sensors inside the distributor and solder on new wires.) The resistance should be about 1400-1600 ohms if the two pairs are connected in series, a quarter of that if in parallel. Then check the two main wires for a voltage pulse when the engine turns. The third wire may be from the middle (where the two VR sensors are joined in series) and used for the tach. If that’s all good try disconnecting the tach adapter, it may be bad. Then try to borrow another 6A. Report back what you find.
You said, "1. Car will not start after three months of good, reliable runs." So the system was working fine and then it suddenly wasn't? Did it fail while running or was it working properly until last the engine shutoff and now won't function? Any work done on the car that could have affected the circuitry - either directly (working on electrics) or indirectly (accidentally broke/disconnected a wire? In any case, the tests recommended should identify where the problem lies.
The third wire may instead be a common ground in which case check for a pulse from each other wire to the common ground. If you don’t get a pulse you have a bad VR sensor (or two), or more likely the wires are broken and/or shorting.
Wow, Derek. Unreal. Thank you for the effort. I checked the gray wire and it does seem in very poor condition. Side note. I am buying a multi-meter today. Realizing my inexperience, I also contacted a local shop that said it can check my coil (as long as I have it out of the car...). Hi Mike. Exactly. The car ran really well late this spring until about two weeks ago. I took about a 40-minute drive, nothing stressful for the car, and then parked. Two days later, I regrettably started but only to reposition in the garage. She wasn't running but for about five minutes until I shut her down. Another two days later, I attempted to start and nothing. Good fuel. Good engine starter but no fire/spark. I have personally done nothing as far as electronics. The ECU and tach adaptor seem to be the significant mods/additions. I certainly could have bumped a wire as a I filled the transfer case with oil but that was two months ago. I will check for wire condition yet again and post photos. I understand! Thank you, Derek. Gentlemen. I want to thank you sincerely for your and everyone's help. I have work to do! Dane
The process of elimination continues. Coil results: Primary: 2.0 ohms Secondary: 8 kilo ohms Looked to be within tolerance. Summation. 1. New spark plugs 2. Fuse and fuse/relay box look good 3. Distributor visually inspected. It was clean. 4. Coil appears to be fine.
Next time you have to change front bank spark plugs: Get a normal spark plug socket, take the foam gizmo out (if it has one), that is used to grab the plug. Take a 2 foot piece of heavy twine, or cord, something that won't break, 3/32" or thicker should work, tape the twine to the side of the spark plug socket with a couple wraps of electrical tape,and drop the socket down into the plug hole, using a correct length extension, stick it into the plug socket, loosen with a ratchet, remove ratchet from the extension, use your fingers on the extension to unscrew the plug. Separate the extension from the plug socket (you don't want an extension or socket that this requires a lot of force to pull apart, as you need to do it with one hand, modify the extension if necessary), remove extension, use twine to pull socket out of the hole. Take a 6" piece of fuel hose and shove it over the end of the spark plug, and remove the plug from the well. I use the fuel hose to start the new plug into the threads, also, as it gives you good feel that it isn't cross threading. Repeat tool insertion and extraction as above to seat and tighten the new plug. You can R&R the front bank plugs with the air box on in perhaps an hour or so. If you back doesn't give out. Bozeman, Eh? I went to MSU 1975-1980. The place has changed. The Rockin' R bar used to be a place where ****kickers and college kids got into giant brawls of a couple hundred people that spilled out onto main street on Saturday night, it looked like a yuppie latte place, when i was thru there three years ago.. Doug
Wow, that is complicated. This is all I do. 1. Removal: Use the appropriate swivel spark plug socket without the rubber inside, undo the spark plug completely, and pull the tool out leaving the spark plug in the hole. Then remove the plug with a magnet. 2. Installation: Gently drop the spark plug into the hole, then slip the socket over the plug, spin the socket in the clockwise direction until it seats and a little more. Remove the socket. Just don't use the rubber sleeve inside the socket so it cannot get stuck inside the hole.
Thank you for the detailed description! I used a flexible magnet stick for socket and plug. Perhaps it is my inexperience, but those front four really kicked my butt. I was born and raised in Kalispell (Flathead 1990 but aeronautical bachelor's at UND), and I remember Bozeman then. Not to rant but I truly despise going into Bozeman anymore; the atmosphere is far too arrogant. Property values continue to climb so it will be great when I sell my house, and I leave in 2023. I will not be sad leaving Montana as it is no longer the Montana you and I know. Thank you, again, for the plug change description. Dane
Magnets are great until you bump something and the magnet looses its grip and whatever you dropped ends up on top of the starter, next to the block. Doug
Is this on a carb car with the deck lid and air cleaner box in place? If so, please clue me in to what swivel socket you use, it sure isn't the one that came in the original tool kit. A normal socket with a long enuf rigid extension on it to allow a ratchet to slip on, won't clear the firewall. Socket/wobbly/rigid extension combo had issues also, maybe my extension was too long as that wouldn't fit. Trust me, I am not into complexity if it can be avoided.. Regardless, taping a string to the socket greatly aids retrieval if something comes loose. Thanks, Doug
Removal: Get a magnetic spark plug socket (has a magnet structure bonded inside the socket itself that goes over the insulator structure but doesn't actually touch it -- nothing to stay stuck on the plug after installation, yet holds the plug for removal). Installation: Slip a ~5" long piece of 5/16" fuel line over the insulator maybe 1/4". Allows you to gently lower the spark plug into the hole, and has enough grip to start the threads by hand by turning the fuel line, but can be easily pulled off once the treads are engaged. Too dangerous to use the socket to start the threads IMO. Also works well on the flat 12s where you can't "drop" the plug into the hole.