240 dies under load idles rough

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Scuzzy_1250
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240 dies under load idles rough

Post #1 by Scuzzy_1250 » Mon Mar 05, 2018 4:11 pm

So I'm the 4th owner of this 69 and it's been a pain in the but since it got it. The wiring was trash and i got it enough to get by. Now my issues is it's running like death. It drove fine for a little while. Then it got progressively worse. I rebuilt the carb Holley 1940 and at first it would flood out all the time. Turned out to be junk in the needle and seat. Then would idle fine and die once i put it in drive. I tweaked the timing a bit and that went away. After that issue was solved it drove around fine for a few days. I fouled out plugs which blew my mind cause a size under stock. Which would be 68, i jumped down to a 65, and i had a lean pops through the carb. I went back up to 68, the lean pops went away. But still junking out plugs. I had another back fire through the carb. At that point the truck won't hardly drive at all. It idles rough, it misses and it dies under load. I took it up the road to a shop to throw a timing light on it. And he had problems finding the timing marks and it didn't go anywhere. Today i put new wires cap coil plugs and still runs terrible. I located the 0 on the pully and marked it clear for the timing gun. After timing I'm stuck on what else i should check any ideas? Any help is much appreciated. Also I'm new here so if this belongs in a better post please move.

I have some YouTube links of videos i took of the tuck running.

https://youtu.be/JRtJUjlnfOE

https://youtu.be/dZGmwBgl7FI

https://youtu.be/Er8bwZKQXko

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Shorty
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Re: 240 dies under load idles rough

Post #2 by Shorty » Mon Mar 05, 2018 6:41 pm

I had a nearly plugged exhaust in one of my trucks and it would barely run and backfire thru the carb.......
85 F150 on 78 bronco frame C6 np205 welded dana44 front, trussed posi nine inch rear. EFI exhaust manifolds into one 2 1/2" rolls on 35x12.5x15 Maxxis Trepador.

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Re: 240 dies under load idles rough

Post #3 by Daubee 1978 » Mon Mar 05, 2018 8:03 pm

I would do a comp. check. If it sat for a while you may have an intake valve not seating with could cause a intake back fire.

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Re: 240 dies under load idles rough

Post #4 by Stonebreaker » Mon Mar 05, 2018 8:20 pm

The thing to do is to be systematic in your troubleshooting. You've been working on the spark, finish going through the entire electrical system until you're getting a reliable spark at the plugs - check for frayed wiring, check your coil, check your alternator, etc. Then start on your air. Is your air filter clean? Do you have cats? Try disconnecting the exhaust and see how it runs. If it runs ok without the exhaust, you have a plugged cat. Then start on your fuel. Check your fuel filter, then the fuel pump (torn diaphram maybe, or a bent cam rod?) and then go through your carb. After you've eliminated all of that, either the engine will be running fine or you know you have major engine work ahead of you.

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Re: 240 dies under load idles rough

Post #5 by pmuller9 » Tue Mar 06, 2018 4:03 pm

Still looks and sounds like a carburetor problem.

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bubba22349
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Re: 240 dies under load idles rough

Post #6 by bubba22349 » Tue Mar 06, 2018 8:16 pm

X 2 first thing you need to do is a compression test the vacuum readings jumping around indicate valves that are not sealing or cylinders with low compression. X2 that carb could also use a good cleaning and rebuild. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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Re: 240 dies under load idles rough

Post #7 by Scuzzy_1250 » Sat Mar 10, 2018 12:40 am

Sorry y'all i have not had time to get to the truck to continue trouble shooting. My in-laws are in town and i have to entertain them. But tomorrow, I'll be picking up a compression Gage and will move forward with trouble shooting.

Do any of y'all know where i can find literature on the truck for cheap or free?

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GPGoverMPG
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Re: 240 dies under load idles rough

Post #8 by GPGoverMPG » Sun Mar 11, 2018 9:46 am

Local library, my local one has lots of maintenance manuals people have donated after selling there rides. (I know, print is dead)
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Re: 240 dies under load idles rough

Post #9 by Scuzzy_1250 » Sun Mar 11, 2018 5:20 pm

Ok so here is where I am with compression

1. 2. 3. 4. 5. 6.
130 125 120 120 130 110



So I got it at zero as best I could, but my timing marks is jumping around so I cant be sure. I can't get my base line.

I do have 12v at coil. Here is the video of the timing mark jumping

https://youtu.be/zV7uJOfRE4o

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Re: 240 dies under load idles rough

Post #10 by Scuzzy_1250 » Sun Mar 11, 2018 5:28 pm

Is it possible for the dizzy to jump teeth with out braking,?

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Re: 240 dies under load idles rough

Post #11 by pmuller9 » Sun Mar 11, 2018 5:46 pm

Is it a points distributor?

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bubba22349
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Re: 240 dies under load idles rough

Post #12 by bubba22349 » Sun Mar 11, 2018 5:55 pm

Scuzzy_1250 wrote:Is it possible for the dizzy to jump teeth with out braking,?


No! Your compression test seems a bit low too. Are the plug wires, cap and rotor in good condistion? :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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Re: 240 dies under load idles rough

Post #13 by Scuzzy_1250 » Sun Mar 11, 2018 7:38 pm

So I reset the points to .017 and it runs so much better. I have to dial it in but holy gezz it's such leap.

The compression test I did cold due it not running at the beginning of the day. A dry and cold test.

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Re: 240 dies under load idles rough

Post #14 by pmuller9 » Sun Mar 11, 2018 9:58 pm

Nice!
When you get a chance, take the distributor cap off and see how tight the shaft is by trying to move the rotor side to side in several directions. If the shaft bearing is worn and the shaft can float back and forth there will be some spark scatter.

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worken2much
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Re: 240 dies under load idles rough

Post #15 by worken2much » Mon Mar 12, 2018 7:46 am

Point gap, (dwell) effects timing. After adjusting your point gap, then set your timing. After fully warmed up, adjust your idle mixture & idle speed.

Bet it purrs like a Tomcat in a dairy...
Rule #1. Six Cylinder Racers Have Longer Cranks.
Rule #2. Unless your given name is Richard...don't be a dick.

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Re: 240 dies under load idles rough

Post #16 by Scuzzy_1250 » Sun Mar 18, 2018 1:23 pm

So I'm back at it yall. It ran fine for a day. Then it went right back to missing again. -_-


https://youtu.be/I3ObWVPwNqk


I really checked my points and it's missing and stumbling again. Dies under load....

Rebuild the carb again??? But actually chem dip it this time? Hmmmmm

Any input?

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Shorty
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Re: 240 dies under load idles rough

Post #17 by Shorty » Sun Mar 18, 2018 8:45 pm

If the point adjustment made a big difference in how it ran (as suggested by a previous post) then you are barking up the right tree I think. Have you considered an electronic ignition conversion (pertronix or something similar) to eliminate the points?
85 F150 on 78 bronco frame C6 np205 welded dana44 front, trussed posi nine inch rear. EFI exhaust manifolds into one 2 1/2" rolls on 35x12.5x15 Maxxis Trepador.

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Re: 240 dies under load idles rough

Post #18 by Scuzzy_1250 » Sun Mar 18, 2018 11:49 pm

It's something I started to read on. Is it all just plug and play I wad also reading that dome dude prefer duraspark over electric ig. What do y'all thing?

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Shorty
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Re: 240 dies under load idles rough

Post #19 by Shorty » Mon Mar 19, 2018 8:38 am

If you have a truck to pull the parts (wiring harness, control box, distributor) then duraspark II is great but the pertronix just screws into the distributor where the points would have been. I have an old farmall tractor that was very hard to start and I couldn't seem to set the points but when I installed the pertronix (two wires, two screws) it has started instantly every time.
85 F150 on 78 bronco frame C6 np205 welded dana44 front, trussed posi nine inch rear. EFI exhaust manifolds into one 2 1/2" rolls on 35x12.5x15 Maxxis Trepador.

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Re: 240 dies under load idles rough

Post #20 by worken2much » Mon Mar 19, 2018 10:12 am

Very possible it's a bad condensor. Have seen only a couple times. Missing, stumbling would come & go with no rhyme or reason. Idle fine, any load would buck & jerk. Sometimes hard to start.

Good luck,
Worken2much
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Re: 240 dies under load idles rough

Post #21 by GPGoverMPG » Tue Mar 20, 2018 7:41 am

I'm currently running duraspark if it breaks you can get replacement parts easy. I run the pertronix stuff in other cars it also works super well.
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Re: 240 dies under load idles rough

Post #22 by Scuzzy_1250 » Sat Mar 24, 2018 6:10 pm

So today about in a new set of points and a condenser. Set my gap and not it doesn't want to start at all. So I'm checking my power. At my bat I have 12v
Coming out from my key switch I have 12 v

Once I connect to my coil I have 5v

So I get a voltage drop. That's no good. I remove my ground from the coil and the POS coil terminal jumps back to 12v I ground it out it dives back to 5v I'm not sure if I have things hooked up wrong I don't have a diagram to reference. Any input???

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Re: 240 dies under load idles rough

Post #23 by brandoncw » Sat Mar 24, 2018 8:35 pm

Scuzzy_1250 wrote:So today about in a new set of points and a condenser. Set my gap and not it doesn't want to start at all. So I'm checking my power. At my bat I have 12v
Coming out from my key switch I have 12 v

Once I connect to my coil I have 5v

So I get a voltage drop. That's no good. I remove my ground from the coil and the POS coil terminal jumps back to 12v I ground it out it dives back to 5v I'm not sure if I have things hooked up wrong I don't have a diagram to reference. Any input???

Have you tried finding a wire diagram on google? Might have some luck, if not id get a service manual. Good luck
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Re: 240 dies under load idles rough

Post #24 by pmuller9 » Sat Mar 24, 2018 9:01 pm

Scuzzy_1250 wrote:So today about in a new set of points and a condenser. Set my gap and not it doesn't want to start at all. So I'm checking my power. At my bat I have 12v
Coming out from my key switch I have 12 v

Once I connect to my coil I have 5v

So I get a voltage drop. That's no good. I remove my ground from the coil and the POS coil terminal jumps back to 12v I ground it out it dives back to 5v I'm not sure if I have things hooked up wrong I don't have a diagram to reference. Any input???

You get 5 volts because there is a balast resistor in the line between the ignition switch and the coil + terminal. That is correct.
If the points are open and you get 5 volts at the coil it means there is a short to ground in the distributor, possibly an error when you installed the new capacitor and points.

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Re: 240 dies under load idles rough

Post #25 by Scuzzy_1250 » Sat Mar 24, 2018 10:58 pm

So I have the condenser screwed to the dizzy. The. I have the lead coming from the condenser going to the points lug. On that same lug is the ground wire out to the negative termanal to the coil. That's the way the previous owner had it that's the way I put it back. I'll see if I can sag a picture. It probably is wired wrong then. I knew j had a group short. I just did the know where or why.

Anyone know if they sell digital copies of shop manuals I can access asap?

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Re: 240 dies under load idles rough

Post #26 by bubba22349 » Sun Mar 25, 2018 8:31 pm

Scuzzy_1250 wrote:So I have the condenser screwed to the dizzy. The. I have the lead coming from the condenser going to the points lug. On that same lug is the ground wire out to the negative termanal to the coil. That's the way the previous owner had it that's the way I put it back. I'll see if I can sag a picture. It probably is wired wrong then. I knew j had a group short. I just did the know where or why.

Anyone know if they sell digital copies of shop manuals I can access asap?


Sounds like you have the wires hooked up correctly! Is the condenser mounting strap been tightened snugly to the Distribitors point plate? Did you ever check the Distribitors shaft for excessive side play as pmuller9 advised you in his above post? X3 might be a bad condenser many cheapie types are, NAPA is one good brand or just swap your old one back in for a test to see if it works. What point gap are you using now? Basic setting is 024 -.027 and you would really want to be seeing a 37 to 39 degrees of dwell on your meter for the best results. Do you have your spark plugs gapped at .034 to .035? Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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Re: 240 dies under load idles rough

Post #27 by worken2much » Mon Mar 26, 2018 8:25 am

They start much, much better if there is 12 volts at the coil during cranking. If you don't already have one, add a wire from the crank position of your ignition switch / circuit to the output side of the ballast resistor. This will put 12 volts, (only during cranking) where you currently are showing 5 volts.

You will need a diode, in the new wire, (Radio shack<$2) to stop current back feed. Otherwise, you won't be able to shut your motor off. A diode is the electrical equivalent of a check valve in a hydraulic circuit. It allows electrical current to pass one way only. Obviously, correct orientation is important.

Had one race car setup for several years without the 12 volt to crank wire in place. About 95% of the time it would fire up okayish. That other 5%, it would refuse to even try. Since adding the 12v circuit, it fires on the first cylinder, every time. Reliable as an anvil.

Good luck,
Worken2much
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Rule #2. Unless your given name is Richard...don't be a dick.

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Re: 240 dies under load idles rough

Post #28 by 86f250straight6 » Tue Mar 27, 2018 6:25 am

I have had problems similar to what you are describing many times when bringing an old car or truck back from the dead. I would definitely reccomend taking off the carburetor and dismantle and clean it with some brakekleen and torch tip cleaners for the small orifices, then blow out with shop air. Soaking the carb in a bucket of cleaner helps loosen up the goop inside, but if you dont take it apart and clean it afterwards it can actually make things worse cuz all the gunk that got loosened up is now floating around inside and its only a matter of time before it clogs again.

But, before you even mess with the fuel i would make sure your spark is right first. I definitely suggest getting an ignitor to replace the points. In my experience points are unreliable and dinosoar technology compared to what we have available now. I believe one cause of your problem could be excess dwell (coil on time) which can overheat the coil and cause an intermittent miss as it heats up. This can be from incorrectly set points, but with most replacement cheapo points the springy strap part is not always strong enough to close the gap quickly at higher rpms causing excess dwell and thus coil overheating.
I'm trying to build a truck that I can't break :bang:

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Re: 240 dies under load idles rough

Post #29 by B RON CO » Wed Mar 28, 2018 10:25 pm

Hi, .017 is too small a gap for the points. The gap on my 200 is .027. Find out the correct gap for your engine. As mentioned, set the points before the timing.
As the engine is running, advance the distributor timing. Retarded timing will hold the engine back. As you advance the timing, and set the timing by ear, the idle will go up.
Lower the idle and go for a ride. If the engine pings, retard the timing a little until the pinging stops. If it doesn't pong, you can try a little more advance.
I think a big part of the problem is the point gap.
As mentioned, there is a resistor to lower the voltage at the coil, to save the points from burning out. It should start on the @6 volts, but the original system did allow full 12 volts when the starter is cranking.
Good luck
B RON CO. Still workin' on it!

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Re: 240 dies under load idles rough

Post #30 by Scuzzy_1250 » Wed Apr 04, 2018 1:42 am

Hey dudes just an update. I have not gotten around to the truck in a bit. I was finishing up my Harley now that I have that running pretty well. My focus will be back on the truck.

I did check the shaft for play and there way at least not that I could pick up.

As far as the 12v line to the coil when I rewire the truck I'll definitely work that in. What kind of diode is needed?

I'm no pro at points by any means. But I'm just gonna go electric ig, so I can rid it of the problem. Besides to buy a dwell meter is about the same price

I'll keep y'all updated

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Re: 240 dies under load idles rough

Post #31 by Scuzzy_1250 » Sat May 05, 2018 1:55 am

Good news gents after much delay and all I finally drop an electronic ig in and ditched the pos points and runs really nice now. I'm real happy with it thanks to all y'all for the help. Now to work on the trans.

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