Backfiring, and other strange issues

[bil1024]

SO running carb with 302, carb is Holley with electric choke and Holly fuel pump. First issue;

I had it running but belt slippage problem had to remount the crank pulley, put back in time. Car starts and backfire's right away, popping thru exhaust, plugs are getting soot, adjust mixture no help. Does not stay running.

The one wire alternator and a ground wire it gets smoking hot, literally it smokes

Using the mechanical linkage from Fortes, right were it mounts to the carb, its hot ? Just at that certain point, could it be engine ground issue ? But that's weird, how would one spot get hot

Let me know what you think thanks guys

[Just puttering]

Is the wire hot from current flow or the exhaust. Im thinking exhaust. If not, do the wires get warm with key on? Do you have 12v at the alt.

Double check the timing pull a valve cover and make sure you are on TDC. Make sure your timing mark is correct. Then check the distributor, make sure its on plug 1. Make sure all plug wires are correct.

When it starts are you getting advance in the timing. At one point my advance was not working and the headers got so hot they were glowing just after starting the car and sitting at an idle.

[jwhit]

also double check firing order 302 can have 2 differnt firing orders it will be based of what cam you have
i like to find tdc on crank and then line it on to 10 btdc to set distributor

[65 Cobra Dude]

Engine ground to chassis!

Henry

[NAZ]

Am I correct to assume this is a first start?

OK, most serious problem first. If any of the conductors (wires) from the alternator are getting hot enough to smoke, you need to replace them as chances are the insulation is compromised. Make sure that both the ground wire and the positive wire are sized to carry the current the alternator is rated for. Don’t guess, look it up as an undersized conductor can start a fire. Google is your friend.


Have you adjusted the valves yet? As most street cars have hydraulic lifters, I’ll assume yours does too. If you have adjustable rockers you can adjust the valves without running the engine by using one of these tools with a drill motor to get oil pressure to the lifters https://www.summitracing.com/parts/pow-pow101155/applications/make/ford?prefilter=1.


As mentioned above, there are two different firing orders depending on the cam installed. Get with your engine builder to determine what the correct firing order is for your engine. If there is no history on the engine then you have to determine for yourself the proper firing order. It should be either 15426378 or 13726548 http://www.gtsparkplugs.com/firing-order-ford-260-289-302.html . You can determine the firing order by baring over the engine and watching the valves. Pull the plugs and valve covers and it helps to have one of these https://www.summitracing.com/parts/cca-324/applications/make/ford?prefilter=1 I never build an engine without one.


Now that you’ve determined the proper firing order and have the wires run correctly, next step is to ensure your TDC marks are actually aligned at TDC. You’ll use a TDC stop like this https://www.summitracing.com/parts/pow-pow101330 to locate the exact TDC position and confirm your timing pointer is aligned with the TDC or zero mark on the damper.


Once you’ve confirmed TDC you can set the timing and start the engine again. If you were not able to set the timing statically (if you have a CD box you can’t static time your ignition) you need to get a timing light on there right quick as if it’s too retarded you’ll heat the headers hot enough to burn the paint very quickly.

I encourage you not to skip any of these steps.

[Desert Cobra]

Same problem with my Ford 306. It was cam and firing order. That takes care of backfiring and black spark plugs, and no performance (as you are running on about 5 cylinders). I had a distributor hot wire and hot coil until it got hooked up correctly. Not sure on alternator. Good ground to engine, adequate wire size. How about battery state of charge? If its real low the alternator may be over-working? Stick with it. Once I got it sorted all was right with the world.

[bil1024]

Thanks all, will start with NAZ suggestions and get better ground for engine

[bil1024]

Am I correct to assume this is a first start?

OK, most serious problem first. If any of the conductors (wires) from the alternator are getting hot enough to smoke, you need to replace them as chances are the insulation is compromised. Make sure that both the ground wire and the positive wire are sized to carry the current the alternator is rated for. Don’t guess, look it up as an undersized conductor can start a fire. Google is your friend.


Have you adjusted the valves yet? As most street cars have hydraulic lifters, I’ll assume yours does too. If you have adjustable rockers you can adjust the valves without running the engine by using one of these tools with a drill motor to get oil pressure to the lifters https://www.summitracing.com/parts/pow-pow101155/applications/make/ford?prefilter=1.


As mentioned above, there are two different firing orders depending on the cam installed. Get with your engine builder to determine what the correct firing order is for your engine. If there is no history on the engine then you have to determine for yourself the proper firing order. It should be either 15426378 or 13726548 http://www.gtsparkplugs.com/firing-order-ford-260-289-302.html . You can determine the firing order by baring over the engine and watching the valves. Pull the plugs and valve covers and it helps to have one of these https://www.summitracing.com/parts/cca-324/applications/make/ford?prefilter=1 I never build an engine without one.


Now that you’ve determined the proper firing order and have the wires run correctly, next step is to ensure your TDC marks are actually aligned at TDC. You’ll use a TDC stop like this https://www.summitracing.com/parts/pow-pow101330 to locate the exact TDC position and confirm your timing pointer is aligned with the TDC or zero mark on the damper.


Once you’ve confirmed TDC you can set the timing and start the engine again. If you were not able to set the timing statically (if you have a CD box you can’t static time your ignition) you need to get a timing light on there right quick as if it’s too retarded you’ll heat the headers hot enough to burn the paint very quickly.

I encourage you not to skip any of these steps.

Thanks NAZ engine is stock 89 out of mustang, I did the rebuild, right now #4 plug is not firing well, it shows no sign of carbon or anything

[NAZ]

Use a systematic approach to troubleshooting and go down the list of items I suggested, you'll figure this out. It's likely a firing order issue but you should follow the all the steps to fully eliminate any other contributing issues. I have also seen OEM timing pointers way off from zero at TDC which will screw with your timing. It's just part of the build process.

You will easily find what cam firing order by baring over the engine and watching the valves. Won't take you long to get this resolved.

[GWL]

I had backfiring due to a bad distributor or cap. I had a Mallory distributor I'd bought from another forum member many years ago. At first start it started right up, I timed the engine but upon driving it I got some popping through the exhaust. I worked with the timing a bit but finally when I changed out to a stock Ford distributor I had it no longer backfired. I don't know what part of the distributor was causing the problem but I've read that a bad cap can cause cross firing through cracks in the cap. Maybe someday I'll stick the Mallory back in, start it at night and see if I can detect any cross firing.

George

[bil1024]

UPDATE:

So found #4 and #8 wires swapped, next going onto checking the timing with valve covers off