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stalling 318 port engine

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l7t1y5

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1979 318s in a f32 trojan....port engine stalls at low idle when throtle is applied....Also dosent seem to rev as freely as starboard...I just ran her 175 miles in 2 days with the port engine if anything being a little more thirsty than starboard.....Any ideas....
 
l7t1y5 said:
1979 318s in a f32 trojan....port engine stalls at low idle when throtle is applied....Also dosent seem to rev as freely as starboard...I just ran her 175 miles in 2 days with the port engine if anything being a little more thirsty than starboard.....Any ideas....
Click to expand...
I clean the carb,first
check for growth and good prop(shaft movement)Alighnment at neutral
then go to sticky distributor mode and spark
 
The Monkey nailed it: Poor accelerator pump reaction in the carb, and a sticking advance mechanism.

On the carb, be sure the linkage rod that operates the accelerator pump is in the hole CLOSEST to the carb body--that will give a maximum squirt.

On the distributor, pull the rotor off, put a few drops of oil on the felt pad below it. Then replace the rotor and 'flip' it back and forth a minimum of a HUNDRED times to free it up. (Put a song on the CD player and flip 'til it's over.)

If that doesn't do it, start looking at plugs and wires.

Jeff
 
fastjeff said:
The Monkey nailed it: Poor accelerator pump reaction in the carb, and a sticking advance mechanism.

On the carb, be sure the linkage rod that operates the accelerator pump is in the hole CLOSEST to the carb body--that will give a maximum squirt.

On the distributor, pull the rotor off, put a few drops of oil on the felt pad below it. Then replace the rotor and 'flip' it back and forth a minimum of a HUNDRED times to free it up. (Put a song on the CD player and flip 'til it's over.)

If that doesn't do it, start looking at plugs and wires.

Jeff
Click to expand...

What would be the next step after plugs and wires? Got there, but still have this problem. Engine runs good at idle and at speed, but getting from idle to speed is a challenge.

One piece of potentially useful information, I replaced one of the advance springs since the old one rusted and broke. I couldn't find exact part springs, but based on a recommendation on another thread in this forum I purchased a spring set from JEGS. I tried to match the spring as close as I could, but who knows? I have tried experimenting with other springs to see if that would solve the problem, but none seem to make a difference.

Also, there is a new carb on this engine. The one thing that does seem to make a difference is adjusting the idle mixture screws. Before I go too crazy down that road, could this be a source of the problem?

Thanks!
Carl
 
Dialing in more idle richness will help, but the problem will remain: Your acclerator pump shot is not enough to overcome the lean condition upon throttling up.

What type of "new carb" did you install, another Carter AFB?

Jeff
 
fastjeff said:
Dialing in more idle richness will help, but the problem will remain: Your acclerator pump shot is not enough to overcome the lean condition upon throttling up.

What type of "new carb" did you install, another Carter AFB?

Jeff
Click to expand...

It's a shiny new Edelbrock 1409.
 
fastjeff said:
Dialing in more idle richness will help, but the problem will remain: Your acclerator pump shot is not enough to overcome the lean condition upon throttling up.

What type of "new carb" did you install, another Carter AFB?

Jeff
Click to expand...

So is it possible that with a brand new Edelbrock 1409 this is what is causing the problem?
 
I had the same problem last weekend. Both 318 engines had problems idling. My older engine had problems keeping high rpms. I believe it was the 10% ethanol in the fuel that is causing the issues. I not sure if it has casued the old gas tanks to send dirt into the carbs or if the gas lines are deteriating. The 1409 carb is acting worse than the original Carter AFB. Both motors run OK at 2000 rpms.
 
Could also be electrical. I had identical problem on my port motor.
It was low voltage to the ignition ecu and coil.
My failing house battery was draining the port motor battery.
I had them paralleled and the alternator regulator was shot.
You should have about 9 volts at the coil when idling. I had 4 to 6 volts.
 
..." I had 4 to 6 volts. "

I've seen that as well on mine but they run fine.

I hate to say this, but your Edelbrock may have the same issue as one of mine had (and another as reported here): The low speed passages inside the carb were partially plugged by the lead that the factory uses to seal up the drilled passages. I had to drill out all of the lead plugs, thread the holes, and epoxy screws into the holes to cure the acceleration problem I was having (which was identical to yours).

I talked to the tech rep at Edelbrock about this (and their practice of not providing a vacuum port), but they denied any responsibility! Maybe you could do better? I'll gladly back you up on it if you want me to.

Jeff
 
fastjeff said:
..." I had 4 to 6 volts. "

I've seen that as well on mine but they run fine.

I hate to say this, but your Edelbrock may have the same issue as one of mine had (and another as reported here): The low speed passages inside the carb were partially plugged by the lead that the factory uses to seal up the drilled passages. I had to drill out all of the lead plugs, thread the holes, and epoxy screws into the holes to cure the acceleration problem I was having (which was identical to yours).

I talked to the tech rep at Edelbrock about this (and their practice of not providing a vacuum port), but they denied any responsibility! Maybe you could do better? I'll gladly back you up on it if you want me to.

Jeff
Click to expand...

Well, aren't you the bearer of happy news... Is there any way to visually see if this is the problem without drilling the plugs out? Drilling a hole for the vacuum port is one thing, drilling into the carb... eek.
 
peter_h said:
Could also be electrical. I had identical problem on my port motor.
It was low voltage to the ignition ecu and coil.
My failing house battery was draining the port motor battery.
I had them paralleled and the alternator regulator was shot.
You should have about 9 volts at the coil when idling. I had 4 to 6 volts.
Click to expand...

So I went down to the boat today with a multimeter and checked my coil. It was reading 2.5 - 3.2 volts at idle. Like many of the components on my 41 year old engines it looks original. I'll try replacing it, keeping my fingers crossed.
 
I installed new coils today (replaced both just for good measure), and it made a huge difference. I get from idle to speed almost without hesitation now. But there is still just a bit of hesitation around 1000 RPM.

I bought Flamethrower coils from Pertronix since I have Ignitor electronic ignition installed. After I buttoned everything up I read the instructions (guess I should have done that first). For 8 cylinder engines it recommended removing the ballast resistor. I ran out of time today, so I'll have to go down later to pull them off. But I was wondering if anyone has an opinion about whether that could be causing the hesitation, or is there still something I'm still missing?

Thanks for all the help here... this forum is an amazing resource for those of us with old, I mean classic :) , boats.
 
Ignition is NOT the problem. If you like the way the motors run WITH the ballast resistor, you might consider leaving it in place. Why? If someone leaves the ignition on by accident (motor off) it will not fry the coil--the resistor heats up and limits the voltage.

The hesitation and stalling you have experienced may be due to a lean condition in the idle circuit of your carb(s). My port carb was notorious for this! Drove me nuts for over a year. The solution was to remove the idle mixture screws and gently drill out the hole where the tip of the screws enters. I found out what size the hole was by trying different drill sizes, then enlarged it one drill size. Very easy to do--just don't break off the bit in there! Motor hasn't stalled since, and it runs far better when cold.

Jeff
 
I would look into accelerator pump. At 1000 rpm with hesitation for a quick second it would seem to be the problem. Make sure the lihkage is lubed and making it's full stroke. I run Holly 600 cfm 4bbl with double fuel feeds and the accelerator pump is fully adjustable yo increase the fuel shot volume. Have you checked fuel filters (changed)?
 
sorrry to jump in guys but need some help you sound like you defintly know more than me.

Am having similar probs w 318 and was wondering (runs rough wont low idle and stalls at WOT) how hard is it to clean and maybe rebuild a carter? limited cash as all went to new OLD boat or should i just stay at work to get new? Dont want to tell wife new Old boat needs new s(&(@%*@
 
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