Large misfire Series 1
 

Hello all, as this is my first post, ill do my best to describe what is happening.

The misfiring started a few days ago after I had an issue with my ignition switch (I believe this has everything to do with what is happening). I went to start my car in the morning and it would start fine but die right after I let go of the key, it did this a few times before I realized that I couldn't hear my fuel pump turning on, until the key was turned to just before the point of cranking. From this I figured something in my switch broke, so I wired in a manual switch for the fuel pump and ignition off of the wiring diagram. After the switch was wired in it started and would not die, so I thought my problem was fixed until. I went to go start the car the next day for work, it started fine and it was warming when I noticed that it had a bit of a hesitation and small misfire but I did not think much of it as it was close to freezing out. When I went to go drive it the small misfire turned to a large one and it had close to no power. I have rechecked my wiring and tried it a few different ways but i am not the most experienced with wiring and it is way over my head at this point.

I have checked a few basic things that could have happened like changing to my spare plugs, the distributor looks fine to me and so do the points. I don't want to start blindly replacing parts and hoping for the best.

Any suggestions would help at the moment, Thanks

A little more info on your car would be appreciated. You stated it has points, so we are assuming that its a 79 model year car. What issue did you have with your ignition switch?

If you suspect the switch is faulty, replace it with a known good one and go from there. The switch is separate from the key cylinder, so you won't have to worry about getting a new key. I would start there honestly if that's where you were having issues in the first place.

Sorry for the late reply, work and school have been crazy. it is a 79 model with points. The issue I had was that my fuel pump and ignition would not turn on until the car was cranking as soon as I let go of the key it would cut the ignition off. I have since replace the Ignition switch with a known working one out of a parts car. Thanks for the suggestion, and that problem has been fixed but my misfire remains.

It will be worse some days, were it has almost no power and will stall at a stop if i don't rev it past 1200 RPM I should also mention that this car is an automatic model. (yes I will be swapping once im out of school). Other days it will only misfire a bit and will rev with no problems. It has become a pain to start cold (0 C) but starts no problems hot. A compression test was done a while ago with good numbers but might have to revisit that. Any help appreciated.

It sounds like your carb is due for a rebuild. When was the last time the fuel filter has been changed? Has the car ever sat for a long amount of time? The gas tank may need cleaning

So the car did sit for a long time before I bought it. Since then the fuel tank has been professionally rebuilt and coated inside and out. All the fuel lines have been replace at the same time. It is currently running a new fuel filter in the standard spot and a small inline one right before the carb. The carb has also been rebuilt when the gas tank was being redone. and fuel pressure was checked and it was within spec.

welcome to the board, jeffHJSA. :)

are you sure you don't have an intermittent vacuum leak - like a loose or cracked hose?

Thank you, glad to be here.

I have checked the hoses a few times and have not found anything that sticks out. I do have everything to do my emissons delete, that might be an option. I will check it over a bit better tomorrow though, just to make sure

All the vacuum lines seem to be intact and in decent condition. Not really sure where to go next, maybe the emissions delete is due. Or find myself a timing light and go from there

I'm of little use when it comes to points ignitions. A timing light won't hurt and I think you should definitely confirm your timing, but my gut tells me timing is probably not the issue. I don't have the time to search right this minute, but I will see if I can dig up any threads that might be able to help you. In the meantime, if you feel like sending a couple PMs, then try the members DivinDriver and/or j9fd3s. They may have more useful and sound input - definitely more than me. :)

A few other ideas I'll put out there:
- check your idle mixture
- maybe check your float levels

My thoughts are the same on the timing but I might as well check. Thank you very much for the help, I have attempted to look search through the threads with no real luck. Ill give the PM thing a try, anything helps at the moment. Ill double check my mixture but my float levels look good to me. Another thing that I forgot to mention is that since the first day I started this car it has had a ticking sound coming from under the carb. I thought for the longest time that it was an exhaust leak at the header. Until I removed the header and replaced the gasket, the ticking sound never went away, and the car was running fine so I didnt pay to much attention to it. I have searched this issue as well with little resolve. Im not sure but maybe it is connected to my recent issues.

My guess on the ticking would be a vent solenoid clicking, fairly certain the nikkis had them

Also, when the carb was rebuilt, was the “spacer” replaced? The thick one that goes between the carb and the intake. Alot of people will scrape those gaskets off the plastic, and always have a vacuum leak afterwords, if you PM Jeff20b i bet that will be a question he asks

I think you might be onto something there, I did not replace the spacer I just scraped the gasket off and put a new one on. I remember it being quite difficult to scrape off. Are these spacers somewhat available to purchase? Might as well try that