Alt question.

[blackhat620]

Hey you guys think a poorly performing Alternator could make your truck run bad, could my rich problem be i'm not getting a good enough spark?
I know when I hit the turn signal I can hear the tone of the tuck change every thing time the light turns on and off?

Tex what are you using to determine that your truck is running to rich?

She has no power I mean no guts when I turn her down to 10-14.
Maybe I just need a new engine

Are you measuring your base idle with the vacuum advance disconnected & vacuum line plugged along with engine idle at 800 rpm?

Could plug gap be a part of this issue...

If the plug gap was way to small you could have performance problems, IIRC the spark plug gap on your engine should be .040

 

[Fellro]

Too wide a gap will also cause weak spark.

Only a few things come to mind that would require that much advance. Something up with the timing advance system, either mechanical or vacuum or both, or a lopey cam. Have you checked total timing advance? Without the tape or a timing light that wil show you, it is a best guess, but if your timing doesn't appear to advance, there is your issue. I don't remember the total timing but it seems to me it should be up towards 40-50 degrees. If you have a high lift long duration cam, that will require more base time..

Another question: How does it crank over? If the base time is too far advanced, it should crank hard. You can most of the time find your sweet spot by advancing the timing until it start to dog down a bit on acceleration. Then shut it down and see how hard it cranks. Too hard cranking means too much advance. With as much advance as you are running, it should be cranking pretty hard by stock standards. If you have a radical cam, it will not be as hard. Also, at what rpm are you setting the timing, and (have to ask) are you unhooking the vac advance while setting the timing.

 

[1985 Ford F-150]

Id check how loose that chain is Tex pull the fuel pump off and push on the chain with your finger through the hole and see how much slack ya got.

 

[TexasNomad]

Tex what are you using to determine that your truck is running to rich?
Hmm running rough and smoking black..



Are you measuring your base idle with the vacuum advance disconnected & vacuum line plugged along with engine idle at 800 rpm?
First time i've heard that will try..


If the plug gap was way to small you could have performance problems, IIRC the spark plug gap on your engine should be .040

The place I bought my HEI from told me to run as big of a gap as I could..

Too wide a gap will also cause weak spark.

Only a few things come to mind that would require that much advance. Something up with the timing advance system, either mechanical or vacuum or both, or a lopey cam. Have you checked total timing advance? Without the tape or a timing light that wil show you, it is a best guess, but if your timing doesn't appear to advance, there is your issue. I don't remember the total timing but it seems to me it should be up towards 40-50 degrees. If you have a high lift long duration cam, that will require more base time..

Another question: How does it crank over? If the base time is too far advanced, it should crank hard. You can most of the time find your sweet spot by advancing the timing until it start to dog down a bit on acceleration. Then shut it down and see how hard it cranks. Too hard cranking means too much advance. With as much advance as you are running, it should be cranking pretty hard by stock standards. If you have a radical cam, it will not be as hard. Also, at what rpm are you setting the timing, and (have to ask) are you unhooking the vac advance while setting the timing.

Well, depends on how much I fiddle with the carb. I can get a sweet spot and truck will star with the first touch of the key..

 

[blackhat620]

The place I bought my HEI from told me to run as big of a gap as I could..


Well, depends on how much I fiddle with the carb. I can get a sweet spot and truck will star with the first touch of the key..

Yes a larger plug gap is better than to small, but only within reason. If the plug gap is to small (ie lower than OEM recomendation) then a weak spark will occur and thus incomplete or no combustion (especially at speed). However a large plug gap is just as bad since it can cause the plug not to fire consistently resulting in the same problems as too small a plug gap.
Unless you are running a highly modified engine, then increasing your plug gap is a waste of time and without properly analyzing the engines performance with a larger plug gap, can actually decrease performance. Increasing the plug gap can also results in early ignition component failure, early plug wire failure and increased chance of spark scatter at the distributor,

Another marketing misnomer is "Multiple Spark" boxes for you ignition system and "High Power" coils. The ignition system will only use as much power as it needs to fire the plug not anymore, so even if you have a 60k coil installed, if the ignition system only needs 20k to fire, then that is all that is put out by the coil. A high power coil can put out up to its rated voltage but the actual output of the coil is only what the ignition system needs to operate. As far as "Multiple Spark" boxes, they are a fallacy at high rpm. Increased spark duration (up to 20 degrees) is much more beneficial, but only if you have a high performance engine/high compression engine or an OEM engine with an extremely poor head design.

Bottom line, unless you are running a high compression engine, run the standard plug gap as specified by the manufacture (in your case IIRC .044).

Quit Fiddling with the Carburetor, there is a basic system to properly tune an engine. The engine must be at operating temperature, curb idle must be correct and base engine timing set. If the ignition timing is not set properly first, you are just wasting your time trying to "properly tune" the carburetor. Without the proper tools, tuning an engine by "ear" is very difficult for most people. To properly adjust a carburetor, you are best served with a vacuum gauge and engine exhaust analyzer. Now most home mechanics cannot afford an engine exhaust analyzer, but a vacuum gauge works very well and is easily affordable (Note: obviously a vacuum gauge is extremely difficult to use for tuning on a high performance engine that produces only 2" Hg of vacuum). As for a timing light first choice should be a modern fully advanceable unit. An old fashion flash only unit will work but to use it effectively you need to install a degree tape on the balancer.

I will ask the question again, Tex what are you using to determine the engine is running to rich?

 

[TexasNomad]

Yes a larger plug gap is better than to small, but only within reason. If the plug gap is to small (ie lower than OEM recomendation) then a weak spark will occur and thus incomplete or no combustion (especially at speed). However a large plug gap is just as bad since it can cause the plug not to fire consistently resulting in the same problems as too small a plug gap.
Unless you are running a highly modified engine, then increasing your plug gap is a waste of time and without properly analyzing the engines performance with a larger plug gap, can actually decrease performance. Increasing the plug gap can also results in early ignition component failure, early plug wire failure and increased chance of spark scatter at the distributor,

Another marketing misnomer is "Multiple Spark" boxes for you ignition system and "High Power" coils. The ignition system will only use as much power as it needs to fire the plug not anymore, so even if you have a 60k coil installed, if the ignition system only needs 20k to fire, then that is all that is put out by the coil. A high power coil can put out up to its rated voltage but the actual output of the coil is only what the ignition system needs to operate. As far as "Multiple Spark" boxes, they are a fallacy at high rpm. Increased spark duration (up to 20 degrees) is much more beneficial, but only if you have a high performance engine/high compression engine or an OEM engine with an extremely poor head design.

Bottom line, unless you are running a high compression engine, run the standard plug gap as specified by the manufacture (in your case IIRC .044).

Quit Fiddling with the Carburetor, there is a basic system to properly tune an engine. The engine must be at operating temperature, curb idle must be correct and base engine timing set. If the ignition timing is not set properly first, you are just wasting your time trying to "properly tune" the carburetor. Without the proper tools, tuning an engine by "ear" is very difficult for most people. To properly adjust a carburetor, you are best served with a vacuum gauge and engine exhaust analyzer. Now most home mechanics cannot afford an engine exhaust analyzer, but a vacuum gauge works very well and is easily affordable (Note: obviously a vacuum gauge is extremely difficult to use for tuning on a high performance engine that produces only 2" Hg of vacuum). As for a timing light first choice should be a modern fully advanceable unit. An old fashion flash only unit will work but to use it effectively you need to install a degree tape on the balancer.

I will ask the question again, Tex what are you using to determine the engine is running to rich?

And I will answer you, again. Running like crap sucking more gas then my 460 and blowing black smoke and the exhaust smells putrid makes i've been around enough carb engines to know when one is sick and this poor girl is sick, not to mention my fuel delivery system is doing some real funky things.

By the way I know how to tune a carb I have enough books and how-to dvds I could barf not to mention I was shown by my Uncle a Master Mechanic with over 30 years under his belt and tuning by ear is easy, my not be spot on but! it gets you in the ball park.

 

[1985 Ford F-150]

Just remembered another way to check the timing chain without pullin nothin apart. Get your timing light just a flash only one and look at you mark where youve got it set to. I like to paint it with white out so its easy. If its bouncin any at all then your chains got slack in it.

 

[blackhat620]

And I will answer you, again. Running like crap sucking more gas then my 460 and blowing black smoke and the exhaust smells putrid makes i've been around enough carb engines to know when one is sick and this poor girl is sick, not to mention my fuel delivery system is doing some real funky things.
By the way I know how to tune a carb I have enough books and how-to dvds I could barf not to mention I was shown by my Uncle a Master Mechanic with over 30 years under his belt and tuning by ear is easy, my not be spot on but! it gets you in the ball park.

First off Tex, i am not trying to insult your intellegence, so don't take it that way. Trying to help you out with this problem.

As you stated tuning by "ear" may get you in the "ball park" but it will not get you to peak performance, and No tuning by "ear" is Not easy. It takes practice and a good ear.

You have mentioned multiple problems with your engine its driveability and fuel mileage.

Poor fuel economy, performance, black smoke etc can be caused by improper carburetor adjustment, improper timing, improper plug gap, improper spark plug heat range, improper temp thermostat, vacuum leak and the list goes on.

You have stated that your base timing is about 25 degrees and you have opened up your plug gap on the recomendation of the sales guy at the parts house. Excessive base timing and large plug gap will result in your truck running just like it is.
Black smoke and poor fuel economy will also be cause by a sticking choke, improper fuel linkage adjustment, faulty high idle cam.

Please describe "funky" for your fuel delivery system, a carbureted engine only needs 4-7 psi of constant fuel pressure to operate properly. With more specific information we may be able to help you solve your engine problem without throwing parts at it or a new motor.

 

[m78]

To run at 25* - do you think you put your knew distributer in one notch out ?

 

[TexasNomad]

First off Tex, i am not trying to insult your intellegence, so don't take it that way. Trying to help you out with this problem.

As you stated tuning by "ear" may get you in the "ball park" but it will not get you to peak performance, and No tuning by "ear" is Not easy. It takes practice and a good ear.

You have mentioned multiple problems with your engine its driveability and fuel mileage.

Poor fuel economy, performance, black smoke etc can be caused by improper carburetor adjustment, improper timing, improper plug gap, improper spark plug heat range, improper temp thermostat, vacuum leak and the list goes on.

You have stated that your base timing is about 25 degrees and you have opened up your plug gap on the recomendation of the sales guy at the parts house. Excessive base timing and large plug gap will result in your truck running just like it is.
Black smoke and poor fuel economy will also be cause by a sticking choke, improper fuel linkage adjustment, faulty high idle cam.

Please describe "funky" for your fuel delivery system, a carbonated engine only needs 4-7 psi of constant fuel pressure to operate properly. With more specific information we may be able to help you solve your engine problem without throwing parts at it or a new motor.

Sorry kinda extra spacey today..
By funky I mean the clear fuel filters I run (One before the holley pump and one before the cab) the first filter will fill up with gas then drain dry while the second one doesn't any any full in it at all.. and it didn't use to be that way i've changed the filters but still doing it.
As for Vac leaks I've spent hours and hours trying to find one, i've tried all the tricks using starting fluid and propane said hell with it and replaced every vac line I could find.
Fuel PSI is around 5 ish if my gauge is right.
Dont run a choke
Thermostat is stock or it should be...
The gap is getting changed to day.. But how do you tell the heat rang? I just run the stock Autolight plugs.

 

[blackhat620]

If i understand your setup correctly, you have a fuel filter before the pump (which is partially running dry) and then another filter downstream of the pump installed just before the carburetor (which is running dry)
If the filter before the pump is running partially dry then you have a restriction in the fuel line or pick-up before the pump. Since you are losing fuel volume before the pump this is resulting in fuel starvation, and an empty fuel filter just before the carburetor. This will definitely cause performance problems and make it damn near impossible to adjust the carburetor and timing.

Heat range of plugs is indicated by the model number, and each plug manufacture has there own system. I do not have an Autolight plug chart in front of me, but since you are using OEM plugs, your heat range should be just fine.
As far as plug gap, you should never increase the gap more than .001-.002 at a time while continually testing & re-testing the performance with the increased gap. BTW increasing plug gap for increased performance is a pita and really not worth it unless you are running a race motor.

Also where are you getting the vacuum for the distributor advance, "ported" or "manifold"?

 

[LEB Ben]

Quick question...how on earth can his carb be starving for fuel, if he says it's running rich and blowing black? To me, those two symptoms just don't add up.

 

[TexasNomad]

If i understand your setup correctly, you have a fuel filter before the pump (which is partially running dry) and then another filter downstream of the pump installed just before the carburetor (which is running dry)
If the filter before the pump is running partially dry then you have a restriction in the fuel line or pick-up before the pump. Since you are losing fuel volume before the pump this is resulting in fuel starvation, and an empty fuel filter just before the carburetor. This will definitely cause performance problems and make it damn near impossible to adjust the carburetor and timing.

Heat range of plugs is indicated by the model number, and each plug manufacture has there own system. I do not have an Autolight plug chart in front of me, but since you are using OEM plugs, your heat range should be just fine.
As far as plug gap, you should never increase the gap more than .001-.002 at a time while continually testing & re-testing the performance with the increased gap. BTW increasing plug gap for increased performance is a pita and really not worth it unless you are running a race motor.

Also where are you getting the vacuum for the distributor advance, "ported" or "manifold"?

Great info and thank you for the help, if I remember right when I changed the gas tank on my truck back when I first got the screen on the fuel pick up was crushed and ripped opened so I just take it completely off.. But check this out!
I have my fuel pump on a kill switch and when I kill the pump and the truck starts to finally die I turn the pump back on and both fuel filters will be full of fuel I can watch the filter before the pump and after a while it will pull a bunch of bubbles out of the tank and start doing the weird surging thing again..
Beats the hell out of me.

Quick question...how on earth can his carb be starving for fuel, if he says it's running rich and blowing black? To me, those two symptoms just don't add up.

I'm as stumped as you on this brother i've been fighting this issue for some time now and just getting fed up with it.

 

[1985 Ford F-150]

I had a problem like that with them stupid elctric pumps. I swapped to the good ol mechanical and that filter stays full. Id maybe try that Tex.

 

[TexasNomad]

yeah I may try that but I paid allot of money for this Holley pump.

 

[1985 Ford F-150]

Thats the kind I had and it gave me nothin but trouble.

 

[LEB Ben]

yeah I may try that but I paid allot of money for this Holley pump.

I'm not a fan of epumps on these rigs either...putting a mech. pump on may help the fuel flow...but you still probably have a bigger issue. As for what you dropped on your pump, resell it...they seem to have decent resale value...or save it for a rainy day. You can pick up a carter pump from your local store for $20...or you can get a blinged out Holley like I did for $80.

 

[TexasNomad]

Well Mechpump scare me, that how my first engine got roasted and I shore I'd never make that mistake again.

 

[1985 Ford F-150]

Hows that?

 

[LEB Ben]

How do you roast an engine because of a mechanical fuel pump?