Hard Hot Start

[JasonR]

Hello, I have a '86 Correct Craft with a 351w. I developed a hard/no start when the engine is warm. If I shut it down and immediately start it it will run. If I wait a minute or so it will crank for ever but it will start with ether. Either way it runs great. It has a new holley that ran great last year, Pertronix ignition, new ignition switch and solinoid.

The interesting thing is that I noticed that when it is cranking (and not starting) I can occasionally let off the key and it will either start or sputter once. I took it out on the water and retarded the timing till it started to ping. After this it started great, no problems but the timing is at around -18 degrees. My thinking is that I don't have a strong enough spark and to high of compression when the timing is right and a low enough compression for it to fire then the timing is retarded. It has the stock (old) coil and ballist resistor. Either timing setting the engine runs fine. any input is appreciated. thanks

 

[Reel Poor]

Re: Hard Hot Start

First off reset your timming to factory specs, all your doing is internal damage to the engine by running the timming the way you have it.

Using a volt meter measure the voltage to the coil + terminal while cranking, should have 10+ volts present.

 

[JasonR]

Re: Hard Hot Start

I can't do it now but lets say there is? And now lets say there isn't?

 

[Reel Poor]

Re: Hard Hot Start

If there is...check and see if the spark plugs are getting fire. If ther're not you have a problem somewhere between the coil and the spark plugs i.e. coil, dist. lead wire, petronix module, cap, rotor, coil wire. If they are getting fire...you may have a fuel flood issue.

If there isn't...you have a wire problem from the switch or the starter solenoid to the coil.

When was the last time it was tuned up, plugs, cap, rotor, wires, fuel filters?

 

[JasonR]

Re: Hard Hot Start

Season before last was the cap, rotor, fuel filter. Season before that was the wires. All with a total of about 35 hours on them. The coil and wires are sending a spark when cranked. Is it possible that the spark is not hot enough? Could the coil read less than 10 volts? Why would it start fine with the timing way off only?

 

[JasonR]

Re: Hard Hot Start

Ok, I checked the volts at the posts on the coil. It showed 8 volts with the ignition on and dropped to about 2 when cranking. I then checked the volts at the ballist resistor with the ignition on (not cranking) - 12 volts on the battery side and 8 on the resisted side. I looked at my paperwork for the Pertronix. It says that if you can connect the module positive wire directly to 12 volts and see if it starts. If it does then you have a "low voltage" issue which is common. If this is the case then you are to wire the positive lead to a 12 volt source connected the to ignition switch or the battery side of the resistor which I have done. Don't know if it will fix it because its not in the water and I can't seem to repeat the problem with it hooked up to the hose. With all of this done I still doubt that it will fix the problem. I'm thinking the low volts and the drop is the problem.

Do these engines need the ballist resistor if it no longer has points?

I have on order a new coil and resister just in case these are the problems.

Any other idea. thanks for the reponces RP

 

[JasonR]

Re: Hard Hot Start

Ok, talked to the tech at Pertronix, very nice guy. He said that the modules needs around 8 volts to work. Some can have 7. This makes sense because I noted that when I stopped cranking it would occasionally fire (voltage went up due to the starting not turning). My system does not have a jumper from the starter solenoid to the coil to boost the voltage during starting like I have read in other posts. He instructed me to bypass the resistor and verify the coil has 1.5 or greater ohms of resistance. I asked why if the thing ran with it prior. He stated because the ballist resistor could have been taking care of the resistance the coil was suppose to have and by taking it out now the coil must have it. Ok - off to the digital meter store. I hope this fixes everything. I'll let you know.

 

[Reel Poor]

Re: Hard Hot Start

If you bypass the inline resistor, you need a coil that has an internal resistor. This should fix your problem.

 

[JasonR]

Re: Hard Hot Start

Ok, The direction on the Pertronix says to connect the ohm meter to the two posts on the coil. Everyone I tried came up as 0 ohms, even the ones with the internal resistor or "no resistor needed". This includes the one I have been using with the ignition for the past two years. I don't want to mess this ignition up any by using the wrong coil. Non of them at the autoparts store were listed as "1.5 ohms resisted" like have seen in the marine catalogs. What do you think RP? Is it still ok to go with any coil listed as "No resistor required"?

I messed with the volt meter some more and became more confused. When I had the Pertronix wires hooked up to the coil along with the ignition wires from the ballast resistor and ground it came up to almost 7 volts. When I d/c'ed the Pertronix wire and left the others I did not get a reading unless I touched one post and then grounded the other on the block and I got the same volts as from the lead to the ballist resistor. I starting to think I don't understand how the ignition/coil/points thing works on these, thought I did. Keep her comin with the responces. I have to have it up, running and no worries by the end of next week. Were going on a week long trip to a lake, I can't have any worries. thanks Jason

 

[Reel Poor]

Re: Hard Hot Start

Jason I'm not real familiar with the Pertronics system. Your problem is due to low voltage to the coil when cranking.

 

[JasonR]

Re: Hard Hot Start

I agree and I found several issues.

1 - I'm not coming up with any ohm resistence from my original coil. I am suppose to have no less than 1.5 ohm. I looked at about 5 other coils at the auto parts store and got 0 on all of them. I'm wondering now if I damaged the Pertronix although the engine runs great after it starts.

2- After hooking up the "+" of the Pertronix to the switch side of the resistor I get 7.25 volts at the "+" post of the coil and about 5 on the negative. I get battery level volts on the switch side of the resistor so my resistor is over resisting.

3. I notice that when I shut the key to off and the coil wire d/c'ed fro mthe cap it discharges once. That doesn't seem right.

Are you suppose to use a Balliist resistor or a internal resistor coil to keep the coil from overheating or to keep from damaging the Pertronix electronics?

 

[lilmandavis]

Re: Hard Hot Start

i would 86 the resister and coil, and order a marine resisted coil. run a jumper from the starter solenoid to give it a "boost" when starting. the stuff your getting at the autoparts store is in no way marine grade. with the jumper the system will maintain its 10 - 11 volts. the coil will resist what it dont need. sounds like a faulty circut somewhere. need to pin point which one it is. probably a connection somwhere in it.

 

[JasonR]

Re: Hard Hot Start

Yup thats what I'm thinking. My only concern is the using the right coil. I have one on order that is specific to the ignition but won't be in till tuesday. I need to get some time on it by then so I need to buy a cheapo till then.

 

[bolo78910]

Re: Hard Hot Start

just run a new wire from the key switch an cut of the original wire, then get the pertronix flame thrower coil and you are set. i just install one on a 470, work fine

 

[JasonR]

Re: Hard Hot Start

I tried the "jumper wire" method and I fried my resistor. I hooked the wire from the starter side of the solenoid to the resistor side of the resistor. Fried it in a second which makes sense when I turn the key on it sends 12 volts through the resistor, drops the volts and sends it to the coil and also back feeds it directly to the starter, draws to many amps and poof. Don't know how you guys do it but am curious.

I got another coil one that says "use with external resistor" and a resistor. Installed them everything worked great for about 20 minutes then it went back to the hard start situation, almost worst than before. I have the Petronix wired directly to 12 volts and about 10 colts showing on the coil that drops when I crank. I bypassed the resistor and it started great.

My question is this - Do I need a ballist resistor for one of these coils even if I don't have points? I know they are ment for points style ignitions and the resistor is ment to keep the vols down for the longevity of them but I don't have them anymore. As for the voltage drop I'm starting to wonder if my starter is going south and pulling to many amps. thanks again for all of the help on this forum I wouldn't have gotin this far without it. Jason

 

[freddyray21]

Re: Hard Hot Start

you don't need a resistor, but the coil will burn up quick if you don't have one. That is my experience. 351 should have two smaller guage wires from the solenoid one yellow that runs to the key switch and one tan that runs to the hot lead on the coil. The tan one is your jumper wire.

 

[freddyray21]

Re: Hard Hot Start

7.5 volts through the resistor is about right. I would check your ohms meter if you are getting 0 ohms on a brand new coil at the auto parts store. Most coils have the resistance marked on the outside. If it says 1.6 ohms then it should measure 1.6 ohms from the neg to the positive using a good ohms meter. Are you sure you are not using the continuity setting on your meter?

 

[freddyray21]

Re: Hard Hot Start

Ok, The direction on the Pertronix says to connect the ohm meter to the two posts on the coil. Everyone I tried came up as 0 ohms, even the ones with the internal resistor or "no resistor needed". This includes the one I have been using with the ignition for the past two years. I don't want to mess this ignition up any by using the wrong coil. Non of them at the autoparts store were listed as "1.5 ohms resisted" like have seen in the marine catalogs. What do you think RP? Is it still ok to go with any coil listed as "No resistor required"?

I messed with the volt meter some more and became more confused. When I had the Pertronix wires hooked up to the coil along with the ignition wires from the ballast resistor and ground it came up to almost 7 volts. When I d/c'ed the Pertronix wire and left the others I did not get a reading unless I touched one post and then grounded the other on the block and I got the same volts as from the lead to the ballist resistor. I starting to think I don't understand how the ignition/coil/points thing works on these, thought I did. Keep her comin with the responces. I have to have it up, running and no worries by the end of next week. Were going on a week long trip to a lake, I can't have any worries. thanks Jason

Jason it works this way. You have voltage running to the hot side of the coil. The points or in this case the Petronix ignitor when they close (or the magnet activates the hall effect switch) it provides a ground to the neg side of the coil and the coil fires. When you disconnect the petronix you are killing your means of providing a ground to the coil and that is why you have to manually ground the coil to get the voltage reading. Please try unhooking the tan wire on your solenoid. Run a wire from the terminal that the tan wire can from to the hot side of the coil. That will provide the 12v hot start voltage you need.