strobe lamp Q

[Tappy]

Its been a while since i passed this forum , the fiat has been sitting in the garage for a great deal meanwhile Today i took her off for a midwinter spin , placed some neat K&n air filters on her.It all went great .... until i got back home , after a 25 km trip of no worries , she dropped dead 100 meters before the garage , i pushed her in the garage where she fired back up like she never died on me


I believed this could be a ignition problem , a case of bad timing maybe , so i got out the strobe lamp , i noticed the strobe lamp missing once in a while is that normal or does that mean those time the spark also missed ? i have replaced the rotor , rotor cap , cables, coil so don't have a clue what 's causing this Any ideas ?

footnote : i also placed an Allison (crane) electronic ignition module (not new)

pps : i like the spell checker is this a new feature ?

[rlux4]

How is the engine running when the intermittent light is happening?
Ron

[So Cal Mark]

why would you think an intermittent stall is caused by a timing issue?

[rlux4]

Not a stall Mark. I'm thinking if the light is a true indicator, he'd be getting an intermittent miss.
Ron

[So Cal Mark]

he wrote that the car quit running at the end of the drive, then restarted

[rlux4]

Yes he did. But he also wrote that the light was "missing once in a while". I'm trying to zero in on if a bad #1 plug or wire could be causing a related problem. Considering the topic of Tappy's post, this sounds like a logical question to me, but if it's not, I'm ready and willing to be educated.
Ron

[Tappy]

Ok i might have let out some important info ; the car did drive 25 km first , then it stopped and i couldn't restart it at first , there was fuel squirting in the carbs so i figured it it might be a ignition problem. I also suspected the ignition because when i was driving i felt some serious held back when going over 4000-5000 RPM like she wanted to quit on me I thought that the advance wasn't set correctly and was causing some problems when making those high rpm's . First thing i did before i tried to restart was checking the ignition wires. After that she started back up (there might have been a bad connection also) that is why i put on the strobe lamp to check if the timing was set properly. I'm running dual idf's and i read somewhere that Denise had advanced them a little more , last time i drove my car before this was coming back from the garage where they adjusted the webers. Now this garage does classic italians but seeing the vehicles there i would say its an alfa romeo garage. To make a long story short i guessed this guy @the garage set my timing @ 0 tdc instead of -10 or even higher.

When i got the strobe lamp connected i saw the light not "strobing" on equal intervals. therefore the question. Now i had to test for the other ignition wires also , if they miss also from time to time then i guess i have a serious ignition problem that can be the cause of the stalling (when driving the engine probably keeps himself running , only when i braked and slowed down there wasn't enough movement to keep it going , and i would explain the holding back @ 4000-5000 rpm also.

I'm going to test the other ignition wires in an hour or so , I'll post the results here

[TulsaSpider]

Sounds like an intermittent connection maybe. Tell us what ignition (points, electronic) setup you are running and that will help us. I had this happen to me twice, no three times with different causes. It took a while to figure out but I did. One was bad condenser, (I am still running points, converted to a single set) one was a loose condenser, and one was broken wires inside the dizzy and they looked fine but they were broken inside, no problems since then.
Good luck!

[racydave]

Tappy, It is not unusual for a timing light to occasionally miss a few events. A good safe way to check for a strong spark is with a replacment tester spark plug.

[baltobernie]

... also, on a four-stroke engine, the timing light is going to flash every second revolution of the crank. At idle RPMs, this can play tricks with your eyes.

Plus, as others have said, sometimes the capacitor on the timing light does not fully recharge between cycles, so you'll get a missed flash. I concur with the group that the replacement ignition (or its installation) is likely the culprit. The very best way to diagnose problems of this nature is to have a garage with an ignition analyzer look at the ignition output displayed on a CRT screen. Timing, dwell, spark voltage, etc. are all visually depicted. Here in the states, "Sun" is the brand name most associated with this type of equipment.

[mbouse]

should we see the same results on the other three cylinders? if so, would that remove the doubt from the timing light, and place it someplace before the distributor?

[baltobernie]

I don't follow, Mike. If the timing light trigger were attached to spark plug leads 2, 3, or 4, the timing flash would exhibit the same characteristics. The only difference would be the flash would illuminate a different segment of the crank pulley.

If you want to see one flash only on the ignition stroke, you could aim the light at the intake or exhaust cam pulleys, which revolve once per four-stroke cycle, not twice like the crank. Does that help, or obfuscate?

[mbouse]

since you answered my question to my satisfaction, i will proceed to explain my answer in some lengthier prose.

if the strobe light emits the same errant charachteristics using the other cylinders ... the perceived error continues regardless of which cylinder is used... then the error is higher up the ladder toward the source of spark. look to the coil, the and the connections BEFORE the distributor cap.

on the other hand, if the strobe emits consistant flash in the other cylinders, then the problem is at the distributor cap-rotor or plug wire for #1 cylinder.

just trying to put some KOW KUNTRY logic in the process of elimination.

[baltobernie]

I got it. Didn't know which you were Replying to.