Engine issue

[69mustang351W 0]

I got my my mustang out on the road last saturday after approximately 5 months of storing. The engine started easier than earlier springs and the engine ran very well. But today it was the old problem again. It runs well most of the time, but when i really want to load, it doesnt run well. F.ex if I drive in 30 mph and load it a bit hard to get the speed up to 40 mph, its just like only 7 pistons are working, but im not sure. Its much more vibrating than normally. It could be loose cable fittings which loose contact with the spark plug when I load the engine, caused by the vibrations f.ex. Or it may be too less fuel caused by worned fuel pump or incorrectly adjusted float. I changed to new spark plugs last autumn and rebuilt the autolite 2100 carburetor later that autumn.

 

Im gonna check the cable fittings and the float in the carburetor, but I dont believe that will solve the problem. Some hints about what other things to do to solve this problem ?

[foothilltom 33]

I would advise you start with the simplest stuff first. After 6 months, fuel can go bad (at least the current crap we call gasoline in the USA) and could lead to clogged fuel line, clogged fuel filter, clogged carb passages, fouling of plugs and generally poor performance. Do you use a fuel stabilizer during storage? Was the fuel system empty during storage? Was it new gas for the spring drive?

 

If you can rule out fuel-quality issues, then I'd just do the basic timing/dwell checks first. Improper timing fits your problem description.

 

Also, check the vacuum advance...maybe it's not holding vacuum and that would also lead to poor acceleration response.

 

It is odd that it ran great one week earlier, but I'd go from simple to complex in my tests.

 

Good luck.

Tom

[69mustang351W 0]

I guess the fuel isnt good. Didnt use any fuel stabilizator. Well, im gonna get new fuel and a liquid in the fuel to clean the engine and fuel system inside and do the tests. Tested the timing last summer, but it is "legal" to test again. Hope its gonna be better:)

[69mustang351W 0]

It didnt get better.

 

I also tried to adjust the float in the autolite 2100 carburetor on my 351 windsor. In the shop manual, the specifications shows that the fuel level(wet) should be 7/8 inch. Thats impossible, cause if I try to bend the float to get the level down to 7/8, the float touches the bottom of the bowl. Then the inlet valve is closed. So the level has to be higher.

 

And the timing is special: The distributor is turned clockwise as much as possible. The vacuum unit touches the upper radiator hose. If I try to turn it agains the clock, the engine begins pinging. Could it be anything wrong here? I feel that the distributor should be turned more clockwise, but that isnt possible.

 

Could my old 9V coil be to weak for the ignitor in the distributor? Or may the plugcables be bad? Could these things be the reason?

Poor accelleration is the problem.

[LoneWolf2U 136]

Wet float adjustment, The 7/8 inch is the level of fuel in the bowl to make the float rise enough to push needle on to seat to stop fuel from coming in. (miss reading the info from the manual)

 

As for the timing,

Remove the bolt and hold down clamp from the dist.

Raise dist enough to move the rotor 2 teeth clockwise and reinstall clamp and bolt. (you may need to tap the starter to get the oil pump shaft seated back in the dist base)

This will allow you to move the dist while timing without hitting the rad hose.

Reset your base timing at about 6-8* and test drive for responce and pinging.

[69mustang351W 0]

I know the fuel level should be 7/8. It isnt possible to adjust the fuel level down to 7/8. In the shop manual, it is different types of the autolite 2100 carburetor. Some versions need 15/16 at fuel level. Mine needs 7/8. Its almost one inch which I mean is a very low fuel level in the carburetor.To get the fuel level down, the float has to be bent down. The float hits the bottom of the bowl before the fuel level can come down to 7/8. The needle closes the inlet when the float hits the bottom. I bent the float a little, it was proximately 2 mm between the float and the bottom of the bowl. Still the fuel level was higher than 7/8. I guess 2mm between the float and the bottom of the bowl is minimal.

 

I bought the car almost 8 years ago, and I believe I havent raised the distributor earlier. I havent adjusted the valves either. When I bought the car, the engine ran fine. Im positive to move the distributor some teeth counterclockwise, but I just wonder what causes it could be that the distributor touches the upper radiator hose before the timing is correct. Could the ignitor cause that it is necessary to raise the distributor to get correct timing? Or could it be something else in the engine that causes that it is necessary to raise the distributor for rotating it counterclockwise to get possibility to adjust the timing correctly?

[foothilltom 33]

Be sure you have removed your vacuum advance from the distributor when checking/setting the timing. Also, make sure your timing light is adjusted to 0 if it has such an adjustment.

 

As far as your floats are concerned, I generally just use the sight screw to eyeball the fuel level (does a 2100 have a sight screw?). It should just trickle out at proper height.

 

Finally, can you confirm what timing it is running at right now?

[LoneWolf2U 136]

The float hits the bottom of the bowl before the fuel level can come down to 7/8. The needle closes the inlet when the float hits the bottom.

Made me go look at the manual, Cause I have ALL Holleys and its been awhile. No the float rises and the tang pushes the needle down to shut off flow.

 

I bent the float a little, it was proximately 2 mm between the float and the bottom of the bowl. Still the fuel level was higher than 7/8. I guess 2mm between the float and the bottom of the bowl is minimal.

You are supposed to be measuring across the top of the fuel bowl down to the top edge of the end of the float when it has risen enough to stop the flow of fuel and adjust up or down to achive your 7/8 mark.

 

I bought the car almost 8 years ago, and I believe I havent raised the distributor earlier. I havent adjusted the valves either. When I bought the car, the engine ran fine. Im positive to move the distributor some teeth counterclockwise, but I just wonder what causes it could be that the distributor touches the upper radiator hose before the timing is correct. Could the ignitor cause that it is necessary to raise the distributor to get correct timing? Or could it be something else in the engine that causes that it is necessary to raise the distributor for rotating it counterclockwise to get possibility to adjust the timing correctly?

 

Well with this info, timing maybe off due to chain/gear wear.

This too will leads your complaint for poor performance.

 

Simple check for chain/gear wear.

Remove dist cap, Using long breakerbar with socket on front crank bolt rock the crank back and forth while watching the rotor in the dist.

The amount of movement will show the slackness in the chain as the cam turns the dist, and the chain makes the cam move.

Edited April 25, 2010 by Mach1Rider

[69RavenConv 286]

Since your car ran fine in the past, the timing is probably still ok. Like Tom said, think simple. Did you gap the new plugs properly? Are they fouled or rusty? Check your exhaust, if a rodent built a nest in your exhaust, you'll have acceleration problems. Bad fuel is still a possibility: just adding fresh fuel isn't enough, you need to run the old out of the system... let us know what you find, we all (most of us) face the same winter storage issues...

[69RavenConv 286]

Mach1Rider makes a good point as usual, worn parts can be a culprit too...

[69mustang351W 0]

Changed to new fuel, it was 1/4 left of the old fuel.

 

The fuel level must be measured from the top edge of the bowl down to the fuel, I guess thats right. Its difficult to explain this problem by words :)

 

I have changed timing chain once, 6-7 years ago, maybe that is worn. Im gonna check it.

 

I cant confirm what timing it is now. But I lissen that when I turn the dist. counterclockwise, the engine begins little pinging.

[foothilltom 33]

I re-read your original post and I still suspect fuel delivery. If your car was running great prior to storage, I would stick with things that could be related to degrading fuel quality and avoid the big stuff for fear of introducing new variables.

 

That gas sat in your carb bowls for 5 months. It could have lacquered up the tiny passages. Your fuel filter could be clogged. Your fuel pump impeller might be struggling to keep up.

 

Now that you've torn into your carb, it's possible you've introduced other issues with the floats, but this is what I would recommend:

 

* Pull your plugs and inspect them for tell-tale signs of lean/rich operation. This is useful information for moving forward.

 

* Consider replacing your fuel filter. It's a cheap piece of insurance.

 

* Treat your fuel system with SeaFoam (or equivalent product in your country). I believe it calls for putting some in your fuel tank, some in your crank case, and some down your carb with the engine running. This stuff is pretty amazing and will clean everything in the fuel system.

 

For $15 US, you might solve your problem. If not, at least you can enjoy the huge white cloud you'll produce :)

 

You really should set your timing precisely. Do you have a timing light? Going by ear is OK for some, but I wouldn't trust my ear. Make sure you disconnect the vac advance.

 

I'd then check your vac advance unit. Do you have a vacuum pump? The unit should hold a vacuum. If it doesn't that could totally explain your poor accelleration behavior.

 

After that, it starts getting into areas that I don't understand well. I am a big fan of simple/cheap diagnostics and component replacement before going too crazy.

 

Good luck, man.

[69mustang351W 0]

My car didnt ran perfect before it was stored, but better than earlier that year(2009). There was some accelereation problems then also.

 

The fuel filter and plugs was replaced last autumn, and the carburetor was rebuilt at the same time.

 

I dont think the autolite 2100 has a sight eye

 

Ive already put something in the fuel that should "clean" the system

 

Good response here:)

 

My plan is to replace the old 9V coil with my flamethrower coil from pertronics, check the plug gaps and do something more with the float in the carburetor. If these things dont help, I may have to check the timing chain. To rotate the crankshaft, I have to remove many parts as fan and pulley. How long should a timing chain work. Is it ordinary to change it each 10.year or something like that?

 

Another detail: If I try to turn the dist. counterclockwise, the idle rpm becomes redused and the engine dont run smoothly when I drive a trip. I guess this means that I have to adjust it clockwise.

[LoneWolf2U 136]

The fuel level must be measured from the top edge of the bowl down to the fuel, I guess thats right. Its difficult to explain this problem by words :) [/quote.]

No what your trying to measure is the top of the float NOT THE FUEL. With a straight edge across the top area of the carbs bowel front, Place your finger on the floats tang and press down.

this will raise the float to the level it needs to stop the fuel from flowing into the bowl. Now adjust the float level up or down to get the 7/8 inch spacing from the top of the float to the straight edge.

Edited April 25, 2010 by Mach1Rider

[LoneWolf2U 136]

If these things dont help, I may have to check the timing chain. To rotate the crankshaft, I have to remove many parts as fan and pulley. How long should a timing chain work. Is it ordinary to change it each 10.year or something like that?

 

Another detail: If I try to turn the dist. counterclockwise, the idle rpm becomes redused and the engine dont run smoothly when I drive a trip. I guess this means that I have to adjust it clockwise.

 

 

You don't have to remove anything from the engine to check for chain wear. With a helper to watch the rotor for movement, Rock the crank from below the car using a socket with a short extention and bar.

You will not have to rotate the crank that much to see the slack in the chain. If the crank/dampner moves more than 1- 1 1/2 inch the chain/gears are worn.

[69mustang351W 0]

Mach1rider, the meaning is not to start a conflict here, but in the shop manual its written that it is the fuel level which has to be measured when its fuel in the carburetor (wet). It also stands that the measuring has to been made 1/4 inch from the wall, because the surface of the fuel is concave ( higher at the edges than in the center). Its many methods, but in the shop manual, they use the fuel level

 

The float/fuel level can be measured wet and dry, off course, when its done using the dry method, then its the float level which has to been measured

 

Here is an ok link: http://hurtle.com/cars/mustang/fixes/carb/

 

Anyway I talked with a mustang pro, and he told me that the fuel almost always should fill 3/4 of the bowl when the needle closes the seat

 

 

I now have my plans, I hope it helps:)

 

 

Messages of the results will be written here

[LoneWolf2U 136]

LoL... no conflict here but, I stopped using the wet method long ago.

The wet settings were causing a flooding problem after engine runs and get upward in heat.

The fuel started to perk in the carb even with the spacer in place and untill I started doing a dry float set it was a constant problem.

[jimmystang 13]

As a Mechanic I would not adjust ignition timing by ear on a standard engine.

Set everything to the manufacturers specs.

Also if the car breaks down under load look toward the high tension side, things like leads, plugs dist cap, coil & rotor.

Stop guessing and start from the start. Correct diagnosis is important.

[bigperm2 10]

I am with Jimmy on this one. I think I had responded to a post you had earlier and you replaced your points with a pertronix unit, so you have lost the last set timing. I know a lot of people have had success timing by ear, but I don't get it, and using the light is the only way you can be sure it is correct. On your first post, you indicated that you think you have a miss. Have you checked all your plugs and wires? A worn cap and rotor can cause a miss also. As tom mentioned, the plugs will tell you if you are rich or lean.

[69mustang351W 0]

Ive already got help from a person with mechanic knowledge. He thought it was something wrong with the ignition. I understand that you may think that im a guy with less mechanical knowledge caused by these simple questions, but I have some knowledge:)

 

Today, I drove and the engine was worse. I believe its one plugwire which has a break, so Im gonna check the plugwires this weekend, maybe with a ohmeter. The next checks like timing will come when I have enough time. Im also replacing a cam on a European 86 Ford Sierra, so its enough to do:).

 

I adjusted the float up today. If the carburetor is flooding, can this be compared with how the engines behaviour is when its running on 7 pistons?

 

Sometimes when I turn the distributor in one specific direction, I can hear it clearly that the timing gets worse, with other words thats the wrong direction. But to adjust with precision, the light is needed.

 

In an earlier post, someone wrote that the damper with the timingmarks has a possibility to be moved in relation to the cranskshaft by itself during all the years the car has been droven caused by wear. Then the timing will get wrong. Its only a possibility, so im gonna use the light soon trying to get the timing correct.

[69-70 mach 1 10]

I had alot of the same problem's you are having. Tried the wet 7/8'' -dry 31/64'' float adjustment. (newly rebuilt carb) No change how the car ran...turn's out it was a defective power valve. Replaced it with a Holley part # 125-75 7.5 power valve. You may want to try that...

[69mustang351W 0]

The power valve in my carburetor was replaced with a new standard power valve, but the power valve you mentioned may work better.

 

If my working with the ignition system dont give results, maybe Ill try your idea

[foothilltom 33]

It really would be interesting to know what tests you've done; especially if you've set your timing correctly. With a problem you've described (poor performance under load?), there are any number of suspects. It's best to rule them out one at a time, starting with the crucial/obvious stuff.

 

I would advise you to not go poking around in your carb until you have "stabilized" the other stuff. The previous poster makes a great point about the Power Valve and it could very well be involved in your performance problem, but it's best to approach that systematically and with proper diagnostics.

 

PVs are rated for a particular level of vacuum and you could introduce more problems if you don't have a good understanding of your engine's vacuum behavior, especially just before it stumbles under load. A "standard" PV may be rated for 7.5" but this may not be what you need at all. There are easy tests you can run when/if you're ready to suspect the carb, but I'd be careful not to jump the gun.

 

Again, if you have time, let us know what you've done and what, if any, impact that had on your engine behavior.

[69mustang351W 0]

No tests yet, many other things to work with also:)

 

Results will come afterwards

[69mustang351W 0]

I replaced the original coil (9V) with my flamethrower coil (12V). I also used a new wire from the ignition to the coil, bypassing the resistance wire. And the engine ran well, also under load. Great performance. I havent set the timing yet, maybe it will run even better. I guess its more or less generally necessary to use a 12V coil if the ignitor , which I also have, is used.