SOLVED: Still running poorly, still having vacuum issues

[cfmustang]

Unfortunatly, I am going to run under the assumption that the new one was bad and the old one was okay. The reason is if this is not true, I have actually made no improvement over the last year and I would be eactly where I started a year ago...with an undrivable car.

If it were that, quite simply, I would be putting the car up for sale.

 

[69.5Mav]

During idle and deceleration, blowby production is very low, but intake manifold vacuum is very high. This causes the pintle inside the PCV to fully retract against spring tension. The positioning of the pintle provides a small vacuum passage and allows for low blowby flow to the combustion chaimber.

From: http://www.autoshop101.com/forms/h63.pdf page 3.

cfmustang
Your old PCV valve is probly leaking and providing enogh air to lean out your massively rich mixture. The new one is most likely not leaking which is why it works worse. Return the new one and get another one, if it works the same as the first new one then it is most likely the old one that is working incorrectly.

Your problem IMHO is to much gas getting into the intake manifold for the amount of air flowing. Most likely its a leak in the carburator. Either a power valve that is leaking, a float set to high, a torn gasket, or some other machanical fault. Where did you get this carb from? If from some vender, have you called them to discuse the problem? I talked to Stovebolt Six last week and they informed me that with rebuilt carbs it's possible to get a bad one rite out of the box. You need to fix the rich condition first!!!

What kind of gas mileage are you getting 5 to 8 mpg?

69.5mav

 

[cfmustang]

I'm not kidding. If it is still a massivly rich condition, I am accepting offers on the car.

That would mean I have been chasing my tail for over a year now with NO IMPROVEMENT WHATSOEVER. I do not have the time or the patients left to fully recap everything I have tried. However, the carb was doing this before and after its rebuild. The carb and been taken off the adapter repeatedly and I am willing to guarentee that there is NO air leaking at that point. People keep telling me that it must be a vacuum leak causing the rich condition but I have been over every inch of the engine and while I have found and corrected some, there are no more.

The carb was purchased from Clifford going on 15 years ago. It was rebuilt by a member of this forum a few months ago. Milage? Can't say. My gas gauge is broken (bad sender) and I have been spending too much money on the stinking engine to fix anything else. I can tell you that looking down the throat of the carb at idle, the carb is bone dry (as it should be) so it should not be a incorrectly set float or leaky needle valve. Also, now with the old pcv valve, if I cover up part of the throat of the carb (to richen up the mixture), it runs terribly, so it is not lean however unplugging that vac tee makes it run rougher too so it is not too rich.

How do I prove that the current pcv valve is leaking. That may be the last test I do as the owner of this car...

 

[gtm1086]

While the carb I sent you may not be the same exactly as the one you have. Have you tried bolting it on to see how it runs? You don't have to hook up the throttle. Just bolt it up and see if it idles better. Can't hurt at this point.

 

[cfmustang]

I will.

It is going to take some work, thats all. It is a mirror image (reverse) of mine so I will hae to fab up some fuel line to reach the inlet and take a closer look at one of the ported vacuum ports. It is slightly bent and appears to have a small crack. Perhaps UPS was too rough with the package...

Sorry to be so salty. Lousy day at work and then finding ou that I am probably at square one really has me annoyed...

 

[Anonymous]

Install the carb that he sent you!!

You have a bad carb as I said in the 1st part of this discussion.

Was the PCV valve just a generic one you grabbed off the shelf or was it specifically for a 200 6? They are all different and can not be interchanged.

You will never get the 272 cam to idle at anything under 900-1000 rpms....Thats the same cam I was running in mine for the past 4 years until I switched to a even bigger one this past winter. It does have the tendency to make the car shake when it is in gear at idle unless you install a stall converter as I did.

Doug

 

[Anonymous]

The new one was some generic aluminum valve from autozone. Is is common to get bad pvc valves out of the package?

It is VERY common to get all kinds of worthless crap......BRAND NEW......from autozone!

 

[69.5Mav]

cfmustang

That would mean I have been chasing my tail for over a year now with NO IMPROVEMENT WHATSOEVER. I do not have the time or the patients left to fully recap everything I have tried.

1) Relax. There can't be that much wrong with this car. At least you don't have a rod sticking out the side of the block.

However, the carb was doing this before and after its rebuild.

2) My son and his frends rebuilt his carb and spent all day trying to make it run right. turns out they put a new power valve on it that for what ever reason leaked even when sitting on the garrage floor. The next day after finding this I re-installed the old one and the car ran fine. So what wrong, I don't know but you will find it.

The carb and been taken off the adapter repeatedly and I am willing to guarentee that there is NO air leaking at that point. People keep telling me that it must be a vacuum leak causing the rich condition but I have been over every inch of the engine and while I have found and corrected some, there are no more.

3) A vacuum leak will not in general make a car run rich. A vacuum leak in the manifold will add air to the mixture downstream from the venturi. This will tend to lean out the mixture.

The carb was purchased from Clifford going on 15 years ago. It was rebuilt by a member of this forum a few months ago.

4) Who knows.

Milage? Can't say. My gas gauge is broken (bad sender) and I have been spending too much money on the stinking engine to fix anything else.

5) You don't need a gas gage to calculate gas mileage just a good odometer. I don't want to insult you by giving step by step on how. You might just be punchy from work. Sory if this seems personal.

I can tell you that looking down the throat of the carb at idle, the carb is bone dry (as it should be) so it should not be a incorrectly set float or leaky needle valve. Also, now with the old pcv valve, if I cover up part of the throat of the carb (to richen up the mixture), it runs terribly, so it is not lean

however unplugging that vac tee makes it run rougher too so it is not too rich.

6) In an earlier post you said that opening a vacuum line made it run better. If that is still true and you still have fouled plugs it is either to much gas or an oil fouling but since youre compression was reasonable I would tend to eliminate oil fouling as the culprit, does youre engine emit smoke out the tail pipe when cold or hot, if blue than you are getting oil into the combustion chamber if it is black as I suspect is very well might be than you are to rich.

Good Luck
69.5mav

 

[cfmustang]

Sorry. I really was having a bad day further complicated by the realization that a years worth of troubleshooting has gotten me nowhere.

Actually, I wish it was a rod sticking out the side of the engine. At least I would know what the problem is.

The engine did not have any of these problems before the rebuild a year and a half ago. However, it did sit in my parents garage for over 10 years. Once I got it back, all this started. I finally had a forum member rebuild the carb and it has been the exact same leading me to believe all this time that is was not the carb. Especially after the timing issues I discovered.

Actually, whenever someone has similar problems to mine everyone says vacuum leak. I just don't get that. That should lean out an engine, not make it richer just like you said...

Good point about the milage. I wasn't thinking. It will take a while to get a reading though since this car is not my daily driver. I am also reluctant to drive it too far since the gauge is not working. I have already run out of gas once...

I wasn't clear about the vacuum leak issues. When I have the old pcv valve in that is runnung fine, pulling the cap off of the tee causes it to run rough and not faster. Once I put the new pcv valve in, pulling off the tee speeds up the idle and smooths out the idle. So, with the older pcv valve, the mixture is closer on but with the new one, it is running rich (the vac lean leans out the mixture).

I will try to at least bolt on the loaner carb tomorrow. I wont be able to drive with it since it is oriented opposite of mine, but it should at least be able to idle. This should at least tell me if something is wrong inside the carb. If it smooths out, I am carb shopping. If it doen't help...I just don't know.

One thing that does concern me is one of the vac ports in the carb was bent and looks like it may be cracked (happened in shipping? Could be, UPS lost the carb for over a week). I am afraid this may make the test invalid...

 

[Lazy JW]

...... the realization that a years worth of troubleshooting has gotten me nowhere..

Actually, you have made some good progress. Don't give up yet, you are getting closer all the time. All you really need at this point is to get some timing advance into it at idle to compensate for that big cam, then you will be able to sort out the carb problems.

A PCV valve is really just a controlled vacuum leak. You can try a test by simply unhooking it and plugging the pcv port at the carb. In a normal situation this will make it run slightly richer. If it gets better then you know you are running too lean, if it gets worse then it is too rich.
Hang in there,
Joe

 

[69.5Mav]

Cfmustang

I wasn't clear about the vacuum leak issues. When I have the old pcv valve in that is runnung fine, pulling the cap off of the tee causes it to run rough and not faster. Once I put the new pcv valve in, pulling off the tee speeds up the idle and smooths out the idle. So, with the older pcv valve, the mixture is closer on but with the new one, it is running rich (the vac lean leans out the mixture).


I believe you have a compesating problem here. The mixture is too rich which leads to fouled plugs and a rough idle and causing a vacuum leak (pulling the cap off of the tee ) leans out the mixture and corrects the problem. The old PCV valve is leaking too much at idle and is compensating for a too rich mixture. If the mixture were correct then the old PCV valve would be making the mixture too lean and pulling the cap off of the tee would worsen the idle. The new PCV valve does not leak, I am assumming it is good to check you could exchange it for another at no charge and install it ( two bad ones in a row is unlikely) if it acts like the first new one then it is most likely that the old one is bad and is hiding a over rich condition.

So we come back to why is the mixture so rich. Too much gas and not enough air. I have no experience with youre carb but I do know that when attacking a complex interconnecting problem it is best to

1) Take lots of written notes. Start now if you haven't, be verbose.

2) Simplify the problem as much as you can.

3) Do not get distracted by side issues, ie once you've settled questions about compression and or timing, as I believe you have, move on.

What I would do is rebuild youre simple reliable one barrel (and put it on and use a new PCV valve in conjunction with it). Ford designed these to be very easy to use. They may not have a lot of power pottential but it will simplify youre setup. Once you see the engine running right you will be able to narrow youre focus to the two barrel carb and its function. You may be able to give Stovebolt a call 586-739-9601 and discuss youre experieses with them.

When loking down the throat of the carb with the engine running you should never put youre face in line with the carb without protection, if it backfires you could get a face full of fire, a real day ruiner. Use a mirror and a hand lite.

Good luck
69.5mav

 

[cfmustang]

Bah! Suits me right for getting excited. I think something is really wrong with the loaner carb. I got it all hooked up and when I try and start it, gas shoots up out of some port next the the verturis like a guyser.

I am assuming I am connected to the the fuel in port it looked like it, but I can't tell because like I said, the layout is different. Nothing is where it is on my 32/36.

Any ideas?

 

[Anonymous]

Sounds like the float and inlet needle/seat are having some issues....

 

[cfmustang]

I am thinking I do not have it hooked up right. I only had time to hook it up quickly and try to start it before I had to go to a couple ofmy wife's family events, but here is what it looks like hooked up.

I think matv91 may me right and I may be hooked up to the vent, not the inlet...

The yellow is where the carb shot gas out of like Old Faithfull.
The Blue/green is where I have the fuel line hooked up to.
At first I didn't see where else to hook up to, but when I got home, I noticed the plastic plug (red arrow). Is there supposed to be a fuel barb there?

 

[addo]

Now that you mention it! Looks like that may be the issue.

 

[Anonymous]

The fuel line hooks where the red arrow is pointing.....

 

[cfmustang]

There is no place to connect the fuel line to. Do those fuel barbs screw in?

Can I remove the barb from the vent and move it to the inlet? What do I do with the vent, plug it with the plastic plug currently in the inlet spot or do I just leave it open?

 

[wsa111]

Chris, why don't you just put a 2300-7448-350 carb on & see what happens.

It sure can't run worse than the present setup.

If that doesn't fix it sell it or take it to a professional to fix it. Willaim

 

[cfmustang]

I actually have been considering it, except there is now way I'd be able to deal with the throttle linkage issues with a 2300 (linkage to the front of the engine). If I can't even tune a carb, ow would I custom fabricate a linkage?

 

[Anonymous]

You need the right kind of friends to give you the right kind of help....

You don't know anybody??!??