Misfiring while cruising

[Mark Maras]

 @jalexquijano I'm proud of you. An improvement. Interesting that we're back to #4 looking worse than the rest. I think it may look a little better than before.  Do you think that you could swap #4 plug wire with either #3 or #5, Length would be the only problem. Swapping #4 with another wire will allow us to see if the problem stays at #4 or goes to another cylinder with the wire.

 I'm interested in your thoughts on this. You're the one that improved the firing on #3 and #5 by (I'm assuming) checking and adjusting the connections. Can you think of anything specifically you did to improve it?

 

[jalexquijano]

24 minutes ago, Mark Maras said:

 @jalexquijano I'm proud of you. An improvement. Interesting that we're back to #4 looking worse than the rest. I think it may look a little better than before.  Do you think that you could swap #4 plug wire with either #3 or #5, Length would be the only problem. Swapping #4 with another wire will allow us to see if the problem stays at #4 or goes to another cylinder with the wire.

 I'm interested in your thoughts on this. You're the one that improved the firing on #3 and #5 by (I'm assuming) checking and adjusting the connections. Can you think of anything specifically you did to improve it?

 

I burshed the 6 plugs and took the car for a hard run on the highway.  Parked the car and took 3 and 4 out. 

On 9/29/2018 at 8:43 AM, Mark Maras said:

 Ok, If you've completed all the tests and found everything looking good put it back together with good (or new) plugs and take it for a run and then let it idle. I'm hoping that you've improved the connections while doing the tests. Let u

[Patcon]

Those look good. It's an idle issue apparently. I wonder if voltage at idle might be contributing to this. IE weaker spark due to starting with a lower voltage? This might also be due to a spotty wire or wire connection like Mark suspects. Would reducing the spark gap slightly be a bad idea? Less resistance to sparking that way...

[rcb280z]

Mark, can he run a hotter plug in those 2 cylinders? Will that help eliminate the idle fouling? 

[Mark Maras]

27 minutes ago, rcb280z said:

Mark, can he run a hotter plug in those 2 cylinders? Will that help eliminate the idle fouling? 

 I think it might improve it but I doubt that it would be eliminated. There's still something wrong and we're getting closer to the cause, I think.

 

32 minutes ago, Patcon said:

Those look good. It's an idle issue apparently. I wonder if voltage at idle might be contributing to this. IE weaker spark due to starting with a lower voltage? This might also be due to a spotty wire or wire connection like Mark suspects. Would reducing the spark gap slightly be a bad idea? Less resistance to sparking that way...

 Reducing the gap would certainly allow it to fire easier. One could combine both ideas (maybe) and buy a hotter plug and reduce the gap. Who knows, it just might work. BUT, my decades of shade tree mechanic work tell me this is a very simple problem (unless it's Pertronix related) and I refuse (at least for now) to give up. I have the same feeling about this problem as the previous SU problem. Simple problem, simple fix.

 @jalexquijano Have you tried swapping #4 wire with another next to it? After swapping the two wires, warm it up, take it for a fun drive, bring it home and let it idle for a while. Let it cool down and pull all the plugs. That should be the next test. We're getting closer to the problem.?

[jalexquijano]

On 9/29/2018 at 8:43 AM, Mark Maras said:

 Ok, If you've completed all the tests and found everything looking good put it back together with good (or new) plugs and take it for a run and then let it idle. I'm hoping that you've improved the connections while doing the tests. Let us know.

Im taking it for a test drive today and will leave it idling for 20 mins to simulate a traffic jam. Should i leav the timing at 14 btdc?

 

2 hours ago, Mark Maras said:

 I think it might improve it but I doubt that it would be eliminated. There's still something wrong and we're getting closer to the cause, I think.

 

 Reducing the gap would certainly allow it to fire easier. One could combine both ideas (maybe) and buy a hotter plug and reduce the gap. Who knows, it just might work. BUT, my decades of shade tree mechanic work tell me this is a very simple problem (unless it's Pertronix related) and I refuse (at least for now) to give up. I have the same feeling about this problem as the previous SU problem. Simple problem, simple fix.

 @jalexquijano Have you tried swapping #4 wire with another next to it? After swapping the two wires, warm it up, take it for a fun drive, bring it home and let it idle for a while. Let it cool down and pull all the plugs. That should be the next test. We're getting closer to the problem.?

Ill swap the cables and test the car.

[Mark Maras]

Leave the timing at 14 btdc.

[psdenno]

11 hours ago, jalexquijano said:

 Should i leav the timing at 14 btdc?

 

Jalex, it might be worthwhile to go back through the entries in this thread and count the times people have told you NOT to change the timing until you determine if the cables are causing the problem.  That's what troubleshooting is all about - eliminating possible causes one at a time without introducing new variables.

Who's telling you to change the timing?  Someone in a private message on this forum?  Someone in Panama?  A little voice in your head? 

I think you're testing the patience of those trying to help you and may be pushing the limit with many.

Relax, follow the advice as given, or move on.  It's as easy as that.

Dennis

 

Edited October 1, 2018 by psdenno

[jalexquijano]

22 minutes ago, psdenno said:

Jalex, it might be worthwhile to go back through the entries in this thread and count the times people have told you NOT to change the timing until you determine if the cables are causing the problem.  That's what troubleshooting is all about - eliminating possible causes one at a time without introducing new variables.

Who's telling you to change the timing?  Someone in a private message on this forum?  Someone in Panama?  A little voice in your head? 

I think you're testing the patience of those trying to help you and may be pushing the limit with many.

Relax, follow the advice as given, or move on.  It's as easy as that.

Dennis

 

Sorry Denis. I will leave the timing as it is at 14 btdc. I raced the car last night and it accelerates fine. I hope you guys can help me solve this low rpm spark plug fouling. I should have never bought a car that had an engine remanufactured and modified by californa datsun. I should have bought a stock engine.

[Mark Maras]

Although I agree that the timing shouldn't be changed at this time, I doubt that retarding the timing back to 12 btdc would change anything unless a bad connection was bumped and improved. 

[jalexquijano]

Do you think i should open the distributor? Any symptom of frozen wieght? I really dont think so!

[Mark Maras]

 I don't think so either based on your reports of the engine pulling strong.