No Spark Situation / Magnetic Pickup Troubleshooting

Gotta love that wiring . . .
Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by Nut124 »

Alex, please note that I got CW/CCW backwards in by post above. Sorry.

Should be like this:

Slowly rotate the dizzy CW, rpm should start dropping and engine should eventually fade away and stop.

Turning CCW, rpm should rise, until dropping eventually, where the sound changes to harsh. My experience has been that peak rmp is at about 30deg advance. However, it needs to be set it at 10 or so in order not to exceed 36-38 degrees total timing at top end.

Regarding the cam timing marks: I doubt that your timing is off by one full rotation. If it were, the engine would not start at all. I think that may well have been the case before you traced, corrected the plug wires.
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by 18Fiatsandcounting »

It would be helpful to have a look at those cam timing marks if you can, even if you can only get a sideways glimpse.

I think everything has been said (but not everyone has said it), so here's a quick rehash of how I check the timing on an unknown engine:
1. Find the plug wire that goes to the #1 spark plug. Make sure, when you go around the distributor cap clockwise as installed, that the next one goes to plug #3, the next one after that goes to #4, then #2, and finally back to #1.

2. Turn the crankshaft to TDC, using the method of choice. See if the holes in each camshaft pulley are lined up with their respective pointers. If not, turn the engine one complete turn until back at TDC and check again. If both marks aren't lined up in either case, there's an issue.

3. When the engine is at TDC and the cam pointers are both lined up, pull off the distributor cap and verify that the rotor is pointing to the inner contact for the #4 spark plug wire (if the cap were installed).

4. When the engine runs, use a timing light to get to the specified timing at idle. Depends on model year, some are 0 degrees (TDC), some are 5 degrees BTDC, and some are 10 BTDC. As noted before, turning the distributor clockwise retards the timing, and turning it counterclockwise advances the timing. It doesn't take much, just a few degrees of rotation.

5. Quaff a beer when all is well. This step is critical.

-Bryan
AlexD
Posts: 51
Joined: Mon Sep 07, 2020 10:38 am
Your car is a: 1980 Spider 2000

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by AlexD »

Thanks for the continued feedback and education. I did get out to the car earlier and advanced the crank to TDC by way of the timing marks until I could see the holes on the cams through the back of the the timing cover (thanks to spider2081 for that tip!). The intake side seems to be well aligned with the mark but the exhaust appears to be off by a tooth or two (at least by my perspective). Here is a pic of both for your reference.

Image

I did realign the distributor rotor to #4 electrode with everything as TDC as I could get but it again wouldn’t fire (it no longer had the hesitation I’d experienced yesterday though so that was encouraging). When I rotated the dizzy CCW, it almost fired but after a good amount of rotation - I started with the plugs aimed at the drivers side headlight and didn’t get any signs of firing until the dizzy plugs were pointed towards the drivers side mirror.

Ran out of time so had to pause for a bit- might get to it later or tomorrow morning. In the meantime, that’s where we stand…

@18fiats, I can’t wait to get to the last step of your process. That beer is going to taste damn good… :D
spider2081
Patron 2024
Patron 2024
Posts: 3015
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by spider2081 »

Have you removed the spark plugs and inspected their electrodes. Missed timed engines are capable of fouling plugs. If the plugs have a black soot on them I would replace them with new properly gaped plugs.

When you replaced the distributor pick up coil were you careful to check the magnets shape matched the base of the pick ups base. The two are not exactly symmetrical in shape.
Is the pick up gap set to spec?
AlexD
Posts: 51
Joined: Mon Sep 07, 2020 10:38 am
Your car is a: 1980 Spider 2000

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by AlexD »

spider2081 wrote:Have you removed the spark plugs and inspected their electrodes. Missed timed engines are capable of fouling plugs. If the plugs have a black soot on them I would replace them with new properly gaped plugs.

When you replaced the distributor pick up coil were you careful to check the magnets shape matched the base of the pick ups base. The two are not exactly symmetrical in shape.
Is the pick up gap set to spec?
Funny you should mention it because I bought new plugs yesterday with the intent to put them in as soon as I got all this sorted out. About a month or two ago I looked at the plugs that were in the car and found that all four of them had heavy deposits of carbon buildup. I assumed at the time that it was because the car was running rich because of the issues I was having with the coolant thermal sensor. I had cleaned the plugs that are in there now and they have been working OK but when I did pull them to find top dead center recently I saw that they had a good amount of buildup again. It didn’t dawn on me that the plug fouling could be because of a timing issue (because I didn’t realize until now that there may be a timing issue). I’ll pull them today and see if the new plugs help at all.

The pickup magnet was aligned and I gapped the pickup to spec. I will take a peek at the gap todsy however to make sure it’s still correct.
Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by Nut124 »

AlexD wrote:When I rotated the dizzy CCW, it almost fired but after a good amount of rotation - I started with the plugs aimed at the drivers side headlight and didn’t get any signs of firing until the dizzy plugs were pointed towards the drivers side mirror.

:D
Alex, sounds like you maybe turning the dizzy way too much. The change timing advance, in terms of crank degrees, as is customary, is twice the amount of turn in dizzy rotation. Tiny adjustments are needed.

Regarding your cam timing marks: Your car ran fine before all this trouble - right?

If so, it should still run the same once you get this ignition figured out.

The only way the cams could have shifted is if you turn the crank CCW (backwards) and the timing belt tensioner is loose.

Looking at your cam timing marks, looks like both cams are a bit retarded vs spec, exhaust more so. However, I would think the engine should still fire and run like this, if not perfect. I would assess the intake to be correct on the sprocket and the ex being off by one tooth.
AlexD
Posts: 51
Joined: Mon Sep 07, 2020 10:38 am
Your car is a: 1980 Spider 2000

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by AlexD »

Nut124 wrote:Alex, sounds like you maybe turning the dizzy way too much. The change timing advance, in terms of crank degrees, as is customary, is twice the amount of turn in dizzy rotation. Tiny adjustments are needed.

Regarding your cam timing marks: Your car ran fine before all this trouble - right?

If so, it should still run the same once you get this ignition figured out.

The only way the cams could have shifted is if you turn the crank CCW (backwards) and the timing belt tensioner is loose.

Looking at your cam timing marks, looks like both cams are a bit retarded vs spec, exhaust more so. However, I would think the engine should still fire and run like this, if not perfect. I would assess the intake to be correct on the sprocket and the ex being off by one tooth.
Yes the car ran fine before this trouble - idled a bit rough and the RPMs were a bit jittery at times but it started and ran. I suspected the rough idle was a combination of the bad coolant temp sensor (not replaced) and the frayed wire in the magnetic pickup (now replaced) but perhaps I've been dealing with an ignition timing issue all along as well.

Appreciate the tips on the tiny adjustments on the dizzy. While my adjustments were "gradual" moving it from Point A to Point B, it sounds like my incremental changes may have still been too much each time. I'll give it another crack over the next day or so - decided to walk away from it yesterday and get some other stuff done that I've been ignoring. I think me and the car needed to sit and think about how we've each been acting and agree to make amends... :D
AlexD
Posts: 51
Joined: Mon Sep 07, 2020 10:38 am
Your car is a: 1980 Spider 2000

Re: No Spark Situation / Magnetic Pickup Troubleshooting

Post by AlexD »

Haven't had the chance to follow-up here but the troubleshooting continues (with some progress). The "small increments" tip was helpful as I was able to get the car to fire and adjusted the timing. It idled smoother and more steadily than I've ever seen but unfortunately it gasped/stumbled and had no rev/power when I gave it throttle. Since it was due for inspection and I suspected that the next level of triage was the fuel injectors or some deeper penetration that could have me wandering aimlessly and possibly doing more harm than good, I decided to take it up the road to the mechanic and let him have at it. This is the mechanic from whom I bought the car and who had rebuilt the engine a year ago so he knows the car. I told him no rush as it's not my daily driver (although I would love to get a few more weekend cruises while the fall foliage is still on the trees).

He's had it for a few days and called me today to say he's still trying to figure out the culprit. Idle is good, timing is right, and the compression is perfect but no power with throttle so he's focused on the fuel injection. He said the voltage coming out of the coil is crazy high so he's zeroed in there at the moment and is hoping there aren't any issued with the ECU. I walked him through everything I've done so far so he's got the full picture. I should know more in the next few days. In the mean time I'm making headway with every other project around here I've been neglecting in an effort to keep my hands busy since I can't find a way to get myself to sit still...
Post Reply