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Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

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Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

OK so it's been a while that I've provided a update, but this one comes with more questions.

1. Is 7-turns too much to have the mixture screws out? (rhetorical)
2. Is the spacer under the carburetor need to be there? (EGR? PCV?)
4. Has anyone had trouble with the Vacuum operated diaphragm connected to the spacer?
3. Any recommendations for Gaskets when servicing the spacer?

I've considered removing the spacer to replace it with a simple "spacer" without any PCV/EGR plumbing.

The 7-Turn out was working pretty well, but It wouldn't allow for any idle adjustment below 1100 RPM, and the throttle plates were completely closed, was an indication to me that something was wrong, and it seem I found a decent leak in the EGR/PCV Spacer gasket.

Thanks,
Alex

1984 F-250 Std Cab (a.k.a. Harrison), Dana 60 Rear, Dana 44HD Front, Ratio 3.54:1, 351W, 2bbl Motorcraft 2150, 4WD NP208 Transfer Case, 4-Speed Warner T-18..
Med Desert Tan Metallic ("Tan? ..not brown?" <= from CT DMV worker upon registering)

-Teach your Kids to Fish, Hunt, or get them into Cars, and they'll never have the time or money for drugs.

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

Alex - I think you have a vacuum leak. I'm surprised that the idle mix screws didn't fall out at 7 turns, but you shouldn't need them out more than maybe 2 1/2 turns. So you have air coming in somewhere that you are compensating for by running the screws out. And that is why it won't idle below 1100.

And that spacer is a prime candidate for leaks. I don't know for sure which spacer you have, but it is probably an EGR spacer, and the "vacuum diaphragm" is probably the EGR valve.

This is a complex area. If you don't want to run EGR then you will need to change the ignition curve to compensate for the lack of exhaust gas in the mix. So I'd suggest you run EGR. But you absolutely have to make sure there's no leak of air in, and it is easy to have one there. In fact, some of the EGR spacers warped due to the heat and are very hard to seal.

Brand of gaskets. Not Mr Gasket, for sure. Holley or Motorcraft would be my pick.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Thanks Gary,

Now that I think about it, the diaphragm I'm seeing cannot be an EGR, since there is no connection to the exhaust. However it does have another hose coming from the Valve cover which I would imagine addresses PCV. That causes me to what to simplify, and disconnect that system even more. In my first call to the autoparts store, they were frustrated in their attempts to the correct gasket for it. in the meantime I found a Felpro Part number in my search of the web (FelPro 60528), any thoughts about this company? I'm all about OEM but, I hate working with the stealership guys.

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

If your spacer looks like the one below, it is EGR. And the exhaust comes through ports in the intake manifold to a slot below the spacer. The valve opens to let exhaust gas into the intake below the carb and dilute the air/fuel mix with inert gas.

As for gaskets, Felpro is a very good brand and I should have mentioned them.

Gary, AKA "Gary fellow": Profile

FuzzFace2

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Gary Lewis wrote

If your spacer looks like the one below, it is EGR. And the exhaust comes through ports in the intake manifold to a slot below the spacer. The valve opens to let exhaust gas into the intake below the carb and dilute the air/fuel mix with inert gas.

As for gaskets, Felpro is a very good brand and I should have mentioned them.

Gary did you forget the picture

Alex, any way to post up a picture or 2 of this plate?
if this plate is ALUM they have been known to get holes in them from the gases and cause a vacuum leak / poor running motor.
Dave ----

Dave G.
81 F100 flare side 300 six / AA OD / NP435 / 2.75 gear
http://cars.grantskingdom1.com/index.php/1980-Ford-F100?page=1
81 F100 style side 300 six/SROD parts truck -RIP
http://cars.grantskingdom1.com/index.php/1981-Ford-F100

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

Yes, I did.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

In reply to this post by Gary Lewis

Gee, what did I say quite a while ago on the damn EGR plate. I used to stock them at Preston in a Motorcraft source box, both 2 barrel and 4 barrel versions. The highly corrosive exhaust gases will eat right through the inside of the spacer into the throttle bores.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

This post was updated on .

Thanks for the info. I thought i had the fix, a Felpro 60528. Looked great but as I took it out of the package and matched it up the the spacer, I noticed that window dimensions are different. the window of the gasket seems about 1/4'" more towards the bores in the manifold. This does look possible to seal the window from the outside, but it's not great it would have 1/8" actually compressed to make the seal, and restricts the rest of the flow.

Reading what you guys have taken the time and provided, I must note one thing, The valve on the back of the spacer, looks like the "EGR Valve" you guys speak of and show, however the piping goes to a tube that connects directly the the PCV Valve.

If you guys are familiar with the correct gasket, I'm open to go to the stealership even.

The bottom looks like this one:

https://www.ford-trucks.com/forums/attachment.php?attachmentid=188735&stc=1&d=1499378204

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

The thing I've circled is for sure an EGR valve. It should not be plumbed to the PCV valve, but for now you should disconnect it and plug the end of the hose as well as where it was connected. I say that because if you put vacuum to a good EGR valve it will introduce exhaust gas at idle, and it is not supposed to do that. So we need to figure out if the gasket is bad or if someone mis-connected it and that's the problem.

And I've added arrows showing the flow here:

Gary, AKA "Gary fellow": Profile

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Thanks for the "..circles and arrows..", I wished I had the part in front of me right now, as I'm feeling as though I have vastly overlooked a gaping hole in the EGR Valve where the exhaust tubing connected, since I did not disconnect anything from it except for the vacuum hose that you see in the image there. The front of the spacer is plumbed to the PCV valve right?.

Am I crazy?

...you don't need to answer the last part, but I am narrowing down the correct gasket, A nearby parts store provided me with a closer match which, by their documentation is a fit for a '82 351W configuration. Maybe this last part could be a clue of mis-matched/ replaced engine or carburetor component??

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

There is no "exhaust tubing". The exhaust gases come from the head through the intake manifold to a hole where the arrow is pointing, then up into the spacer, back to the EGR valve, and if it is open forward into the air/fuel mix.

The tube to the EGR valve is vacuum to open it - and it closes by internal spring pressure. Which is why I said plug that tube off as well as any vacuum port to which it was connected. That way we know the valve is not going to open at idle.

Gary, AKA "Gary fellow": Profile

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

In reply to this post by Bulletproof250

Ahhhhhh! it all makes sense now! Yes I'm getting close to blocking it all off, forever!

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

For all of those having difficulty finding the right gasket.... Mine was a Felpro 60244, Carburetor Mounting gasket for 302, 351W Eng, 1975-85.

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

So I blocked it All off, Replaced the brake booster line and ran the vacuum advance line right to the base of the carb. I've gotten all of the leaks sealed up. Adjust the mixture screws, and the curb idle, for hours! I have one issue, every time that I think it seems about right, mixture and curb idle. It starts hard. But If I get the screws backed-out way more than normal (4+ turns) it seems to idle and start much better. Am I missing something here? I've got a timing light that gives me RPM, but if I look for the timing mark on the crank I cant even see it, I will say I'm not sure I'm picking up the RPM from the #1 cylinder. Anything is worth a shot at this time. I'm pretty confident that the Carb-rebuild is solid, as the truck drives pretty well. and will stay running.

85lebaront2

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

First, number one cylinder on Ford V8 engines is the right (passenger side) front cylinder. Second, are you disconnecting and plugging the vacuum advance? Third, you could have a bad balancer, after 36 years they can fail, the outer ring is bonded to the inner with rubber and it will eventually fail.

One note, the scale on the balancer runs from 10° After Top Dead Center to 30° Before Top Dead Center (abbreviated ATDC and BTDC) be sure you are going the correct way from TDC.

Bill AKA "LOBO" Profile

Gary Lewis

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

In reply to this post by Bulletproof250

Four turns out isn't bad, but it may mean there is still a vacuum leak. Try unplugging the brake booster and capping off the port to which it was connected. It is possible it has a leak and is the source of the extra air.

But, does the engine idle down well? If so you may not have a problem.

On the timing, do you have the timing light set to zero? A timing light that shows RPM is usually a roll-back unit. Not always, but usually. And if it isn't on zero it'll not show the correct timing.

As for #1 cylinder, I'm sure you know but it is the front one on the passenger's side. So if your light's pickup is on it you are getting triggered by #1. However, it is possible that your harmonic balancer has slipped and isn't showing the correct timing. Have you tried bringing #1 up by hand to see what the pointer shows at TDC?

Gary, AKA "Gary fellow": Profile

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

In reply to this post by 85lebaront2

Gary,

All good points, I hoe to get sometime outside today but I'll try the brake booster first. and double check that 4 turns is, really where is saw the best performance, one-last-time. I have my concerns about the harmonic balancer because even on my first go round with getting this time fired up, I remember cleaning direct off of the timing mark, and i was able to see it. Now I don't see anything.... which leads me to another question. I notice that the timing pointer has a point and then a small circle lower on the indicator, I assume the I am still watching for the pointer to line up with the mark on the Harmonic balance, not to see the "line" through the circle / "window".....

and again,

85lebaront2

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

Alex, the circle is for a timing probe, used with many engine analyzers. It uses a magnetic pickup on the slot in the balancer and requires you to input the offset, ie how far the slot and window are from TDC. The analyzer uses this and the signal to display the actual timing in degrees either as a digital value or on an analog meter.

You are correct in using the pointer against the numbered scale on the balancer. FWIW, I usually put white paint or similar at TDC and the correct setting so I am not trying to read the numbers through the belts and hoses. If you want real fun, older British cars had the marks on the bottom of the engine, usually on the oil pan, which involves lying on the ground to read them and having a helper adjust, same thing on most GM and Chrysler full size vans where the distributor is in the back.

Bill AKA "LOBO" Profile

Bulletproof250

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Just if anyone is curious about gasket part numbers for a 1984 2bbl, EGR Plate

85lebaront2

Re: Motorcraft 2150 2BBL Carb Rebuild- Welch Plugs?

Administrator

Good find sir! Gaskets can drive a person crazy trying to find the right one.

Bill AKA "LOBO" Profile

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