Slow starting when hot

[Big_John]

would crank normally never slowed down with new starter.

Good!

Have you changed/checked the points lately?

 

[pmschmitt]

No I have not. Bought car 3 years ago guess I should have done that. Why do bad points look like? Black/ charred?

Have thought about upgrading to the Petronius but have heard mixed reviews here. What are halls thoughts

 

[Big_John]

The Pertronix has mixed reviews. There's probably nothing wrong with them, but the tried and true Mopar electronic system is tough to beat.

Points should be clean, flat and parallel with each other and adjusted to the correct gap. If you haven't touched them in 3 years... I would be checking them first thing.

In fact... Let's go back to basics here... When is the last time this car got a fresh set of plugs? Cap and rotor?

 

[pmschmitt]

Would bad points cause struggling to start when hot? Car runs great on the road and starts right up when cold. Only seems to struggle after heat soak

 

[Big_John]

Would bad points cause struggling to start when hot? Car runs great on the road and starts right up when cold. Only seems to struggle after heat soak

Well.... It's a maintenance type item that needs to be checked.

When you have a problem, the best thing is to start looking at the basics. Everything has to work correctly at that level and if they aren't right, then you can expect other problems to be magnified.

 

[Speed_Kills96]

If youre experiencing slow cranking when hot it could be a starter issue. Connect a amperage tester to the battery and see how much amps get drawn when the engine is hot vs when it is cold, if it draws more amps than specified, it could point to a faulty starter, or a mechanical engine issue that arises when the engine is warm. Also this kinda sounds like a ballast resistor issue, so do some electrical diagnostics on it to see what resistance it has. If its close to being out of spec, it is most likely the culprit.

 

[pmschmitt]

Thanks speed kills this is a long thread and yes you re correct the starter was failing, but it has been replaced and the car is still struggling to start when up to temp.

 

[pmschmitt]

Big John
Plugs, belts, and wires have been replaced as have fluids
Have not replaced fuel pump or water pump as they have been working fine. Car does not drain battery even when has sat 2-3 weeks it still cranks. I have rebuilt the carb which fixed stumbling during excelleration and cold start problems. I also flushed the automatic tranny fluid and did the 2-3 TPK upgrade. I have also done the amp meter bypass upgrade as illustrated on a site I cant remember the name of "mad" something .

Have not replaced cap rotor condenser or dist cap on distributor.

 

[pmschmitt]

Pics- looks pretty grimey. Probably should have replaced already. I just didn't know wether to go with original or Petronix

 

[Turboomni]

This is a very long thread and I have not read everything so excuse me if I am repeating. In the course of 5 months owning my Fury it has had a problem to hot start. Found loose carb bolts and it helped a bit. Still had a problem and put in a carb heat isolator ,,3/8ths I think from Edelbrock for my Edelbrock 1406 carb.. That helped a bit more. I had the car sent in for a complete dual exhaust and he found the heat riser on the passenger side was stuck on and frozen. He freed it up and that helped a good deal with the hot starts...much improved overall. The car from the beginning when cold would start up very quickly and still does..

 

[Big_John]

Big John
Plugs, belts, and wires have been replaced as have fluids
Have not replaced fuel pump or water pump as they have been working fine. Car does not drain battery even when has sat 2-3 weeks it still cranks. I have rebuilt the carb which fixed stumbling during excelleration and cold start problems. I also flushed the automatic tranny fluid and did the 2-3 TPK upgrade. I have also done the amp meter bypass upgrade as illustrated on a site I cant remember the name of "mad" something .

Have not replaced cap rotor condenser or dist cap on distributor.

Sounds like you have a lot of this already covered and that's good.

Points are probably one of the most high maintenance items on any car from the era. When we had the chance to switch to the electronic ignition, most all of us embraced the new technology.

But going back to your points... Have you checked the timing? Ignition timing can change with dwell angle change.

I would seriously consider the Mopar Performance unit over the Pertronix. Again, it's tried and true. You can buy any of the components locally (distributor pickup, ECU, etc) and you aren't using the ~50 year old distributor as a starting point for the conversion. You can't say any of that for the Pertronix unit.

 

[BJS racing]

I hate to bring up the past but he has already verified a problem and everyone is still working around it and has not addressed it. But what do I know.

 

[Big_John]

I hate to bring up the past but he has already verified a problem and everyone is still working around it and has not addressed it. But what do I know.

He has had several problems. Bad battery, bad starter, bad clutch fan. He's replaced those.

He has had some low voltage problems, but he also was checking them with the bad starter cranking. I don't think he has checked those values since replacing the starter.

Is that the problem you are seeing?

 

[BJS racing]

He has had several problems. Bad battery, bad starter, bad clutch fan. He's replaced those.

He has had some low voltage problems, but he also was checking them with the bad starter cranking. I don't think he has checked those values since replacing the starter.

Is that the problem you are seeing?

The fact that he has less than a volt on the IGN2 circuit from the switch has been the first thing I have talked about addressing from almost the beginning. With a buddy there he could have defunked this with a test wire while starting. I am sure some of the other things have not helped the issue but this one was the easiest and quickest to check and was passed up.

Start the car and drive it until it gets to operating temp when you normally have the issue. Have a wire long enough to go from the battery to the + side of the coil. Shut the car off and make sure it is having a problem starting like you have had. Run the wire from the + side of the battery to the + side of the coil long enough to start the car. If the car starts like it should you likely have a bad ignition switch. If you have the same issue then you have something else going on like the points there were just brought up or a coil breaking down on you.

 

[pmschmitt]

Bjs thank you I will test today and get back with result

 

[Big_John]

The fact that he has less than a volt on the IGN2 circuit from the switch has been the first thing I have talked about addressing from almost the beginning. With a buddy there he could have defunked this with a test wire while starting. I am sure some of the other things have not helped the issue but this one was the easiest and quickest to check and was passed up.

Start the car and drive it until it gets to operating temp when you normally have the issue. Have a wire long enough to go from the battery to the + side of the coil. Shut the car off and make sure it is having a problem starting like you have had. Run the wire from the + side of the battery to the + side of the coil long enough to start the car. If the car starts like it should you likely have a bad ignition switch. If you have the same issue then you have something else going on like the points there were just brought up or a coil breaking down on you.

I think you are right and that should be checked. It's a very easy thing to do and I'm all about doing the easy checks. But I also think, based on the other issues, that he needs to be sure ALL the other pieces are falling inline.

 

[BJS racing]

I think you are right and that should be checked. It's a very easy thing to do and I'm all about doing the easy checks. But I also think, based on the other issues, that he needs to be sure ALL the other pieces are falling inline.

Oh don't get me wrong I agree with you. Every little issue can work together to create a bigger issues. I also think because of the not wanting to start when hot that was putting strain on the rest of everything. May not have created all of the issues may not have even created one of them but it is possible. Trying to sit there and crank on an engine that is not wanting to start will weaken the battery and the starter. Hopefully between all of the input giving here and a lot of it was great info he will get it fixed and it will help the next guy that has an issue like this. I have a hot start problem as well on my fury but it is all carb related. I just don't want to mess with the carb right now. I know how to get it to start so I guess not that big of a deal for me at this time.

 

[superfragl]

May I ask where is your cranking timing at?
If the timing is too much advanced it can crank and start easily when cold, but would not crank as easy when hot..

 

[Speed_Kills96]

View attachment 94925 Ok so to recap.
The car starts great when cold. Starter will crank and even when I disconnect coil to check starter cables the starter never seemed to slow down or get tired.

When the car is up to temp and I shut it off if I come back to start it it will struggle. The starter will turn at what appears the correct rpm for 1-2 second but then will slow down and become sluggish. There is never any clicking.

Tests that have been run:

Battery - would not hold charge and was < 10v when cranking. It was replaced with a new battery but the problem persisted.

Cables to starter- I did a voltage drop to starter and it was less than .5V. On positive and negative So therefore eliminated bad connection and or cables.

Coil- cranking v to coil ( when car is cool) is around 4V and 9V when car is running. I just pulled off the brown wire on starter switch and turned key to on position ( did not crank)and had 11.3V at coil.Placed brown wire back on starter switch and turned key to on and still had 11.3V at coil when not cranking.

So where do I go from here fellas. I feel like Sherlock Holmes. I attached a pic of the engine bay as I am unsure of single or dual ballast resistor.

If there is any voltage drop greater than .2V, on most electronic circuits that are being tested it usually indicates a defective cable or connection.