Starting problems

68stangquest · 03-11-2004, 05:56 PM

Looking for some help with a starting problem on my 68 Mustang.

The car is getting gas and is getting spark. If I turn the key engaging the starter motor it fires up quickly and seems like it would continue running if I left the starter engaged. When I turn the key back to the run position it dies as if it was not getting anymore spark.

The car did start once last night for me. While it was running I was able to check the timing which was right on and the float levels were good.

If I turn the key to the run/on position and use a volt meter to check the volts at the Flame Thrower II coil it reads 8 volts. I'm running the Petronix electronic ignition so I don't have points anymore. The motor is a 1970 351W.

Any help would be greatly appreciated.

68stangquest · 03-11-2004, 07:42 PM

Forgot to mention a couple things: When the car was running last night it ran very well. Idled fine had no misses. If I turned the key off it would fire right back up. However, when I left the car off for a little over 5 minutes it would not refire. Water temp was about 180 and the oil pressure was good.

mustangII460 · 03-11-2004, 07:49 PM

The first part about tunring the key back to the run posistion sounds like the ignition switch is bad.

Pull a plug wire off, ground it too the head (So it sparks) and have someone crank it as you described. See if the spark stops when it quits being cranked.

Giggle it around when you turn it back to run. See if that matters any.

What was the last thing you replaced or worked on before it quit running?

Keep us posted.

68stangquest · 03-11-2004, 09:16 PM

Last night when I was checking spark I connected a couple old plug wires together long enough for me to hold on to and ground on the doorframe while cranking since I didn’t have a helper at the time. When the car was cranking over the spark was good. No spark as soon as I stopped cranking and went to run position. Giggling the key going from start to run didn’t change anything.

I was suspecting the ignition switch as being the culprit but when I turned the key to the on position and checked the coil with a voltmeter it checked out ok. Am I correct in assuming that it is not the ignition switch? Or am I missing something.

As far as the last thing that was worked on its pretty hard for me to tell. Two days ago my car failed Phoenix emissions. Hi on hydrocarbons under load. Passed on everything else. I put on a new carburetor on about 6 months ago and the car has been running great. I figured I was off a little on the mixture so I just figured I would take it to a place here in town and have them run a diagnostics on it. They came back and said that the intake gasket was leaking and would be happy to replace it for $400.00. I declined their offer and told them I would pick the car up. When I went to pick the car up it took three or four tries to get it to fire up. I dismissed it as a fluke and took it home. Last night I went out to start it and had a heck of a time getting it started. When I finally did get it started I found that the timing was off which I reset, front float was way low and gas poored out of the rear float side screw (reset and the floats are good now), and the idle mixture screws were almost all the way screwed out. After I reset everything the car idled good again. But after leaving it sit over night now it wont start. I called the shop back and they said that it started fine for them but said they would be happy to look at it for me if I had it towed to them.

So this is where I sit don’t know if it is just a coincidence or if something else that I feel they fouled up on was done to the car that I can’t think of.

68stangquest · 03-11-2004, 09:23 PM

Last night when I was checking spark I connected a couple old plug wires together long enough for me to hold on to and ground on the doorframe while cranking since I didn’t have a helper at the time. When the car was cranking over the spark was good. No spark as soon as I stopped cranking and went to run position. Giggling the key going from start to run didn’t change anything.

I was suspecting the ignition switch as being the culprit but when I turned the key to the on position and checked the coil with a voltmeter it checked out ok. Am I correct in assuming that it is not the ignition switch? Or am I missing something.

As far as the last thing that was worked on its pretty hard for me to tell. Two days ago my car failed Phoenix emissions. Hi on hydrocarbons under load. Passed on everything else. I put on a new carburetor on about 6 months ago and the car has been running great. I figured I was off a little on the mixture so I just figured I would take it to a place here in town and have them run a diagnostics on it. They came back and said that the intake gasket was leaking and would be happy to replace it for $400.00. I declined their offer and told them I would pick the car up. When I went to pick the car up it took three or four tries to get it to fire up. I dismissed it as a fluke and took it home. Last night I went out to start it and had a heck of a time getting it started. When I finally did get it started I found that the timing was off which I reset, front float was way low and gas poored out of the rear float side screw (reset and the floats are good now), and the idle mixture screws were almost all the way screwed out. After I reset everything the car idled good again. But after leaving it sit over night now it wont start. I called the shop back and they said that it started fine for them but said they would be happy to look at it for me if I had it towed to them.

So this is where I sit don’t know if it is just a coincidence or if something else that I feel they fouled up on was done to the car that I can’t think of.

mustangII460 · 03-11-2004, 09:36 PM

Seems if your getting it started I doubt the switch is bad.

Assuming you have a Holley. On level ground. The primary should be set to just weep gas from the side hole. The secondary I like to have up to the hole, not weeping. Hows the accelerator pump?

If you have a big enuf intake leak that would cause it not to run. Try starving the carb for air a little next time you get it running. Kinda like holding a rag over the carb. At some point of starving with a vacum leak the car usually smooths out because you've increased the fuel mixture by cutting off the air.

Or close off the butterfly a little, choking, next time trying to start.

We'll get this figured out.

68stangquest · 03-11-2004, 10:05 PM

Unfortunately I haven't been able to get it started since last night. But when I did have it running last night it ran very well after making the adjustments I talked about earlier. My floats are exactly where you stated. Front weeping out just a little and the rear is just at the site hole.

While it was running last night I did exactly what you just suggested as far as restricting some of the air from the carb to see if it ran any better and it did not improve the idle as it would if their was a vacuum leak. I do question if their even is a vacuum leak because it does idle very smooth.

As far as the accerlerator pump goes it is pumping a good shot of gas. While it was running last night she reved up very well with no stumbling or hesitation so it seems to be getting a good shot of fuel.

Also sprayed starting fluid in the carb last night to see if that would make any difference which it didn't. I can remember years ago when I was having problems with another car starting I could spray starting fluid in and that car would start up and run until the starting fluid burned off(was a fuel issue with that car). Doesn't matter how much starting fluid I spray in this carb it will fire and run until I turn the key back to the run position.

Forgot to mention I pulled the spark plugs today and they are in good condition. Actually only a few months old.

68stangquest · 03-12-2004, 03:55 PM

Today I put in a new ignition switch to try and start ruling out what could be the problem and unfortunately this did not take car of it.

I am open for anyones suggestions. Could it be that the timing chain jumped and through all of my attempts to try and get it started that some how it jumped back into the proper place for me to get it running the other night?

03-11-2004, 05:56 PM	#1
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Starting problems Looking for some help with a starting problem on my 68 Mustang. The car is getting gas and is getting spark. If I turn the key engaging the starter motor it fires up quickly and seems like it would continue running if I left the starter engaged. When I turn the key back to the run position it dies as if it was not getting anymore spark. The car did start once last night for me. While it was running I was able to check the timing which was right on and the float levels were good. If I turn the key to the run/on position and use a volt meter to check the volts at the Flame Thrower II coil it reads 8 volts. I'm running the Petronix electronic ignition so I don't have points anymore. The motor is a 1970 351W. Any help would be greatly appreciated.

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03-11-2004, 07:42 PM	#2
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Forgot to mention a couple things: When the car was running last night it ran very well. Idled fine had no misses. If I turned the key off it would fire right back up. However, when I left the car off for a little over 5 minutes it would not refire. Water temp was about 180 and the oil pressure was good.

03-11-2004, 07:49 PM	#3
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	The first part about tunring the key back to the run posistion sounds like the ignition switch is bad. Pull a plug wire off, ground it too the head (So it sparks) and have someone crank it as you described. See if the spark stops when it quits being cranked. Giggle it around when you turn it back to run. See if that matters any. What was the last thing you replaced or worked on before it quit running? Keep us posted.

03-11-2004, 09:16 PM	#4
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Last night when I was checking spark I connected a couple old plug wires together long enough for me to hold on to and ground on the doorframe while cranking since I didn’t have a helper at the time. When the car was cranking over the spark was good. No spark as soon as I stopped cranking and went to run position. Giggling the key going from start to run didn’t change anything. I was suspecting the ignition switch as being the culprit but when I turned the key to the on position and checked the coil with a voltmeter it checked out ok. Am I correct in assuming that it is not the ignition switch? Or am I missing something. As far as the last thing that was worked on its pretty hard for me to tell. Two days ago my car failed Phoenix emissions. Hi on hydrocarbons under load. Passed on everything else. I put on a new carburetor on about 6 months ago and the car has been running great. I figured I was off a little on the mixture so I just figured I would take it to a place here in town and have them run a diagnostics on it. They came back and said that the intake gasket was leaking and would be happy to replace it for $400.00. I declined their offer and told them I would pick the car up. When I went to pick the car up it took three or four tries to get it to fire up. I dismissed it as a fluke and took it home. Last night I went out to start it and had a heck of a time getting it started. When I finally did get it started I found that the timing was off which I reset, front float was way low and gas poored out of the rear float side screw (reset and the floats are good now), and the idle mixture screws were almost all the way screwed out. After I reset everything the car idled good again. But after leaving it sit over night now it wont start. I called the shop back and they said that it started fine for them but said they would be happy to look at it for me if I had it towed to them. So this is where I sit don’t know if it is just a coincidence or if something else that I feel they fouled up on was done to the car that I can’t think of.

03-11-2004, 09:23 PM	#5
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Last night when I was checking spark I connected a couple old plug wires together long enough for me to hold on to and ground on the doorframe while cranking since I didn’t have a helper at the time. When the car was cranking over the spark was good. No spark as soon as I stopped cranking and went to run position. Giggling the key going from start to run didn’t change anything. I was suspecting the ignition switch as being the culprit but when I turned the key to the on position and checked the coil with a voltmeter it checked out ok. Am I correct in assuming that it is not the ignition switch? Or am I missing something. As far as the last thing that was worked on its pretty hard for me to tell. Two days ago my car failed Phoenix emissions. Hi on hydrocarbons under load. Passed on everything else. I put on a new carburetor on about 6 months ago and the car has been running great. I figured I was off a little on the mixture so I just figured I would take it to a place here in town and have them run a diagnostics on it. They came back and said that the intake gasket was leaking and would be happy to replace it for $400.00. I declined their offer and told them I would pick the car up. When I went to pick the car up it took three or four tries to get it to fire up. I dismissed it as a fluke and took it home. Last night I went out to start it and had a heck of a time getting it started. When I finally did get it started I found that the timing was off which I reset, front float was way low and gas poored out of the rear float side screw (reset and the floats are good now), and the idle mixture screws were almost all the way screwed out. After I reset everything the car idled good again. But after leaving it sit over night now it wont start. I called the shop back and they said that it started fine for them but said they would be happy to look at it for me if I had it towed to them. So this is where I sit don’t know if it is just a coincidence or if something else that I feel they fouled up on was done to the car that I can’t think of.

03-11-2004, 09:36 PM	#6
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	Seems if your getting it started I doubt the switch is bad. Assuming you have a Holley. On level ground. The primary should be set to just weep gas from the side hole. The secondary I like to have up to the hole, not weeping. Hows the accelerator pump? If you have a big enuf intake leak that would cause it not to run. Try starving the carb for air a little next time you get it running. Kinda like holding a rag over the carb. At some point of starving with a vacum leak the car usually smooths out because you've increased the fuel mixture by cutting off the air. Or close off the butterfly a little, choking, next time trying to start. We'll get this figured out.

03-11-2004, 10:05 PM	#7
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Unfortunately I haven't been able to get it started since last night. But when I did have it running last night it ran very well after making the adjustments I talked about earlier. My floats are exactly where you stated. Front weeping out just a little and the rear is just at the site hole. While it was running last night I did exactly what you just suggested as far as restricting some of the air from the carb to see if it ran any better and it did not improve the idle as it would if their was a vacuum leak. I do question if their even is a vacuum leak because it does idle very smooth. As far as the accerlerator pump goes it is pumping a good shot of gas. While it was running last night she reved up very well with no stumbling or hesitation so it seems to be getting a good shot of fuel. Also sprayed starting fluid in the carb last night to see if that would make any difference which it didn't. I can remember years ago when I was having problems with another car starting I could spray starting fluid in and that car would start up and run until the starting fluid burned off(was a fuel issue with that car). Doesn't matter how much starting fluid I spray in this carb it will fire and run until I turn the key back to the run position. Forgot to mention I pulled the spark plugs today and they are in good condition. Actually only a few months old.

03-12-2004, 03:55 PM	#8
68stangquest Registered Member Join Date: Mar 2004 Location: Scottsdale, AZ Posts: 6	Today I put in a new ignition switch to try and start ruling out what could be the problem and unfortunately this did not take car of it. I am open for anyones suggestions. Could it be that the timing chain jumped and through all of my attempts to try and get it started that some how it jumped back into the proper place for me to get it running the other night?