Faltering with high revs

[Eggo]

Posting this in electrical as not sure if it’s something to do with the ignition or not.

Swapped the inlet manifold gasket recently as was having issues with lack of power and took it for a test drive the other day and it worked perfectly. Have tried to drive it this weekend and every time it falters when it’s in gear and i put my foot down, which it wasn’t doing last week.

It has fuel, the fuel pressure is fine and it doesn’t do it when it’s not in gear. It was having a similar issue previously when the voltage regulator had been overcharging the battery and the battery couldn’t hold the charge and the volts were dropping when i was going.

Yesterday i noticed the volts were on 8 so i charged the battery overnight and thought maybe that’s why it was having problems. today it’s on 12v and i’ve taken it down the road and every time i put my foot down a bit it falters and almost cuts out but the bolts were staying at 12. Does anyone have any ideas on what could be the problem? Have barely driven it since october as been having issue after issue and i’m really missing driving it but feel a bit in over my head with what i need to do to get it going or how to fault find it

 

[pnora]

It would help to know what car it is. Sounds like a charging system problem. You need to correct that first. Ignition systems do not like low or high charging conditions.

 

[Eggo]

It would help to know what car it is. Sounds like a charging system problem. You need to correct that first. Ignition systems do not like low or high charging conditions.

sorry, it’s a ‘73 satellite. it’s at 12v though is that not correct? when it was overcharging previously i sorted that issue, just the symptoms now remind me of then but when it was doing that the volt meter was sat at around 15v. that was about a year ago now though and since i sorted that it sits between 10 and 12 but usually around 12

 

[pnora]

sorry, it’s a ‘73 satellite. it’s at 12v though is that not correct? when it was overcharging previously i sorted that issue, just the symptoms now remind me of then but when it was doing that the volt meter was sat at around 15v. that was about a year ago now though and since i sorted that it sits between 10 and 12 but usually around 12

You should be around 14 when running. You will have ignition problems once you get below 12 volts.

 

[MWbirdLOVER70]

Coil breaking up?

 

[Eggo]

You should be around 14 when running. You will have ignition problems once you get below 12 volts.

Coil breaking up?

i’ve done this check on the coil and between each side it’s about 0.2 and the middle to the positive is high but have checked a brand new coil i’ve just had over from rock auto and that’s the same so not sure if i’m testing it wrong? have disconnected everything from the coil before checking it like it says to

 

[pnora]

Coil breaking up?

High or low voltage will impact the coils performance. He has an obvious issue on the charging system that needs to be corrected first. Why waste time and money on other items when ignoring the obvious. If you called and ignition company complaining about a problem and sort of blaming their product once you tell them about the voltage its game off. They point blank will tell you to fix the charging system and then call back.

 

[Carcinogen]

Does it rev ok in park or neutral?

Weak spark will cause problems when cylinder pressure builds, stumbling and backfire.

Check for proper voltage at coil. Worn/bad; coil, rotor, cap, spark plugs, ballast resistor, check resistance of spark plug wires.

Also check fuel pressure under load at higher RPMs.

I found old wires and connectors that were internally corroded, outer insulation looked OK but insides were bad after 50 years.

 

[LowBikeMike]

High or low voltage will impact the coils performance. He has an obvious issue on the charging system that needs to be corrected first. Why waste time and money on other items when ignoring the obvious. If you called and ignition company complaining about a problem and sort of blaming their product once you tell them about the voltage its game off. They point blank will tell you to fix the charging system and then call back.

I think you need to talk louder, cause people ain't listening. Ask me how I know.

 

[dadsbee]

Yep, sounds like it's running on the battery.. and no charging system working.

Got an electric choke by chance.. lol

 

[pnora]

Yep, sounds like it's running on the battery.. and no charging system working.

Got an electric choke by chance.. lol

Oh Boy. You must be bored.

 

[dadsbee]

Oh Boy. You must be bored.

LOL, well if the OP does and they unplug it they'll gain about 0.3 volts! Consider that my f'd up choke would kill the ECU with a charging system that was working and putting out almost 14 volts.

 

[Geoff 2]

What ign system, points, elec????

You may have something in the electrical system that is pulling a lot of current & preventing the alt from getting to charging voltage. Like something is pulling 40 amps & you have a 45 amp alt.
Points would be more susceptible to low voltage...& misfires.....because it is already a weak ign system.

What I would try. Get a separate, fully charged battery & use that to just run the ign system. You could put the battery in the boot, ground the neg post & just run the pos wire to the ign. Because of the long length, use thicker wire or use two lengths of std diameter in parallel. This would just be temporary to see if it fixes the problem.

 

[Eggo]

Does it rev ok in park or neutral?

Weak spark will cause problems when cylinder pressure builds, stumbling and backfire.

Check for proper voltage at coil. Worn/bad; coil, rotor, cap, spark plugs, ballast resistor, check resistance of spark plug wires.

Also check fuel pressure under load at higher RPMs.

I found old wires and connectors that were internally corroded, outer insulation looked OK but insides were bad after 50 years.

It revs fine in both park and neutral. Have looked at the spark and it seems quite strong. The plugs and leads are new but I have a new coil I can put on. Have ordered a new regulator and ignition control unit as someone gave me some advice that a bad control unit could be the cause so fingers crossed it is that. Will check the wires though for any corrosion and the resistor, thank you

 

[Eggo]

Yep, sounds like it's running on the battery.. and no charging system working.

Got an electric choke by chance.. lol

yeah it's electric choke but I need to set it up again as it's too closed when I start up and it struggles. have to prop the valve open a little bit with a screwdriver or it starts and then cuts out

 

[Eggo]

What ign system, points, elec????

You may have something in the electrical system that is pulling a lot of current & preventing the alt from getting to charging voltage. Like something is pulling 40 amps & you have a 45 amp alt.
Points would be more susceptible to low voltage...& misfires.....because it is already a weak ign system.

What I would try. Get a separate, fully charged battery & use that to just run the ign system. You could put the battery in the boot, ground the neg post & just run the pos wire to the ign. Because of the long length, use thicker wire or use two lengths of std diameter in parallel. This would just be temporary to see if it fixes the problem.

it's electronic ignition. have a spare battery so will try this, thank you

 

[dadsbee]

yeah it's electric choke but I need to set it up again as it's too closed when I start up and it struggles. have to prop the valve open a little bit with a screwdriver or it starts and then cuts out

Well I was 1/2 joking and 1/2 not. Unplug the power wire to the choke and see if it runs better. I had one on my '64 that would make it start to miss and in the end actual kill it just hooking up the power wire, as it's heater element was almost a dead short.