[Santacarl]

Hey All,

I've about reached the end of my shadetree ability. I would appreciate some thoughts.

I'm running a Mallory Unilite distributor (electronic ignition---the one with the LED trigger). I'm also running a Mallory ProMaster Coil (PN 29440). Carb is a 600 CFM Eddie.

Drove the 350 crate engine into the shop a couple of weeks ago after a nice run around town. It ran like a champ; idle great....Shut down per normal.

After 2 weeks of not running I went out and started it up. Ran as normal for about 30 seconds...then died out by dropping idle speed from 750-800 RPM to 0 RPM in a little less than 10 seconds. Sort of reminded me of when you crank on a cold morning and the choke isn't working properly and the engine slowly winds down but in this case choke is working.

Would NOT start back up. I waited a couple of days until I had some time to do some checks. Again, after sitting 2 days, it started up and ran for around 30 seconds and then wimped out again....same pattern.

My first thought was fuel starvation.....pulled the breather and hit the carb linkage and gas jetted into the primaries.... Check; fuel present.

Next I checked the Mallory distributor....Measurements suggested a possible weak spark so I ordered a new Mallory Unilite Control Module PN 605 (the electronic 'eye' module that mounts inside the distributor). Also ordered new distributor cap and rotor...

Got the parts in...installed and got a good test on the Unilite suggesting a strong spark.

Hit the starter and, you guessed it, ran for 30 seconds and gradually died out.

Back to the fuel system I went and swapped out the fuel filter.

Hit the starter and grind, grind, grind over she turns.....but no start this time. New fuel filter is full of gas so apparently fuel pump is working....

It's odd....ran great the last time out then the 30 second run then die.... That would seem to indicate it's not the carb so what else is left????

Anybody have any thoughts? I'd surely appreciate some speculation and things to try that I might have overlooked....

 

[oldcutlass]

You need to see if your losing voltage at the coil when it dies.

 

[Santacarl]

You need to see if your losing voltage at the coil when it dies.

Nope....a little over 12VDC.... I checked that today just to make sure..

I appreciate the response...

 

[oldcutlass]

Are you using a ballast resister? Did you set the reluctor gap?

 

[shovelrick]

It sounds like a bad coil to me

 

[71350SS]

Just want to know you leave it running and it's idling on it's own and then it gradually dies,correct ? So have you tried to give it some gas with the gas pedal to see if you can keep it running ?
I mean that's the first reaction to a motor that's beginning to stall out,right ?

 

[Santacarl]

Are you using a ballast resister? Did you set the reluctor gap?

Yes....to the ballast resister. There's no gap to set on these 'electronic/LED eye' units.....there is on the magnetic type....but that's a whole different varmint....

 

[Santacarl]

Just want to know you leave it running and it's idling on it's own and then it gradually dies,correct ? So have you tried to give it some gas with the gas pedal to see if you can keep it running ?
I mean that's the first reaction to a motor that's beginning to stall out,right ?

Yep.....to question 1.... and Yep to question 2....pedaling has zero effect...

 

[Santacarl]

It sounds like a bad coil to me

Yeah I haven't ruled that out.... Thought I'd exhaust other possibilities before I lay out 150 bucks on a new one to test with.... Unfortunately I don't have an old one around to swap out for a test....

 

[68elky396]

I had a similar problem last year, it turned out to be the brand new cheap reproduction ignition coil from China. After doing some research online about how to test an ignition coil using a multimeter, I found my coil to be defective. I replaced the coil with my old MSD Blaster 2 coil and it's been running great ever since.

Steve

 

[shovelrick]

I really don't remember if a points coil should read 3 ohms and electronic 5 ohms, but it's something like that, do a search?

 

[Santacarl]

I had a similar problem last year, it turned out to be the brand new cheap reproduction ignition coil from China. After doing some research online about how to test an ignition coil using a multimeter, I found my coil to be defective. I replaced the coil with my old MSD Blaster 2 coil and it's been running great ever since.

Steve

Interesting...thanks for the response. It's good to hear from someone with similar issues....

Your thoughts on "cheap reproduction" parts brings to mind the outsourcing our industrial base to other countries..... People wanted cheap....Well, they got what the wished for. Instead of paying a bit more for made in the USA, in return, we get junk. As a famous personality is known to ask.....Cheap products...."How's that workin' out for ya?" Be careful what you wish for because you might just get it.....Grrrrrrr

 

[Santacarl]

Well...Update on the latest in the saga of head scratchers.

I replaced the coil with a NAPA IC12. So, to list replaced parts, I've now replaced the Mallory breakerless Ignition module, Distributor cap, Ballast Resistor, Fuel filter, PCV Valve, and Coil.

Installed the new coil and she cranked right up (fired up after a couple of revs) and, again, ran for 20-30 seconds and died. Will not restart. Same as before. On a side note, once it runs that 20-30 seconds it is slow to turn over and I suspect the timing is a bit high causing that but that shouldn't cause it to die once it does start.... And, no, the distributor hold down insn't loose and the distributor isn't moving around.

The glass fuel filter shows lots of gas inside and if you pump the accelerator linkage gas squirts into the primaries on the carb. I thought it might be the carb but since it pumps gas down the primaries I'd think it would at least fire up temporarily or try to if it was a fuel starvation issue once the engine is running. Once it cuts off it doesn't even try to fire up again but if I let it sit for a day or two it will once again start right up.....run 20 seconds and die....

I've never seen anything like this..... I'm about to give up and have it towed to the local fix it shop and no doubt get ripped off for another several hundred $$. Just thought I'd throw the latest fix attempt out to the forum to see if any that generates any new ideas as to what is causing this.....Before I send for the 'hook'.

As always any feedback is welcome and appreciated.

 

[68elky396]

Check to make sure that the rubber fuel line between the fuel pump and the hard line that goes to the fuel tank is not collapsing when it starts up. Also, you could try replacing the fuel pump. I'm not sure if these were already suggested or not. Man, you do have a real head scratcher. Keep us posted.

Steve

 

[Santacarl]

Check to make sure that the rubber fuel line between the fuel pump and the hard line that goes to the fuel tank is not collapsing when it starts up. Also, you could try replacing the fuel pump. I'm not sure if these were already suggested or not. Man, you do have a real head scratcher. Keep us posted.

Steve

Thanks 68elky.... NEW UPDATE:

I just went out and tried to start again.....checked and I do NOT have 12 volts going to the coil....only going to the ballast resistor and 1 volt at the coil. Last time I checked, when it wouldn't start, I DID have 12 volts.... But I DO KNOW that 1 volt wouldn't fire a pissant up....


I DO have 12VDC (Switched) going to the electric choke.....

Anyone have any idea what could be killing voltage after allowing it to run for that 20 seconds? I've got a couple of thoughts in mind but I'd like some verification without my, at this point, skewed input....haha...

 

[Aml383]

Well...Update on the latest in the saga of head scratchers.

I replaced the coil with a NAPA IC12. So, to list replaced parts, I've now replaced the Mallory breakerless Ignition module, Distributor cap, Ballast Resistor, Fuel filter, PCV Valve, and Coil.

Installed the new coil and she cranked right up (fired up after a couple of revs) and, again, ran for 20-30 seconds and died. Will not restart. Same as before. On a side note, once it runs that 20-30 seconds it is slow to turn over and I suspect the timing is a bit high causing that but that shouldn't cause it to die once it does start.... And, no, the distributor hold down insn't loose and the distributor isn't moving around.

The glass fuel filter shows lots of gas inside and if you pump the accelerator linkage gas squirts into the primaries on the carb. I thought it might be the carb but since it pumps gas down the primaries I'd think it would at least fire up temporarily or try to if it was a fuel starvation issue once the engine is running. Once it cuts off it doesn't even try to fire up again but if I let it sit for a day or two it will once again start right up.....run 20 seconds and die....

I've never seen anything like this..... I'm about to give up and have it towed to the local fix it shop and no doubt get ripped off for another several hundred $$. Just thought I'd throw the latest fix attempt out to the forum to see if any that generates any new ideas as to what is causing this.....Before I send for the 'hook'.

As always any feedback is welcome and appreciated.

You got a fuel pressure gauge on the set up ?

 

[Aml383]

Thanks 68elky.... NEW UPDATE:

I just went out and tried to start again.....checked and I do NOT have 12 volts going to the coil....only going to the ballast resistor and 1 volt at the coil. Last time I checked, when it wouldn't start, I DID have 12 volts.... But I DO KNOW that 1 volt wouldn't fire a pissant up....


I DO have 12VDC (Switched) going to the electric choke.....

Anyone have any idea what could be killing voltage after allowing it to run for that 20 seconds? I've got a couple of thoughts in mind but I'd like some verification without my, at this point, skewed input....haha...

Check the alternator

 

[shovelrick]

Another bad resistor??

 

[Aml383]

Another bad resistor??

It'd potentially act out like that with a bad resistor? Like good enough to start and run but then gets hot or somethin ??

 

[nashville beth]

Do you have good ground wires connected to the engine-firewall ?