on my 78 400 engine i replaced the carb gaskets a few weeks ago still did not run worth a darn give it full throttle and it will bog sputter no power. so i took off the carb. stock 2 bbl.motorcraft 2150? any way when i took off the carb it was very wet with gas between the carb and the thick insulater gasket. the other gaskets were all dry. so is there a thin gasket that goes over the top of the thick gasket and carb base? yes the side stamped this side up was correct. i just checked the carb base with a srtight edge. it looks to have been over tightened the ears are a tiny bit lower. but it did not leak the last time i had it off . other than replace the carb base what tricks if any will help seal it up? two thin gaskets on top of the thick one?

 

Possible defective EGR valve. Have you removed the EGR valve and checked the ports for carbon build up? Remove the valve from the spacer plate, then look inside where it mounts.

 

i took off the EGR valve i did clean it out. it did have a lot of carbon on the valve. the EGR plate has a ton of carbon build up. but the EGR is not connected to any vacuume source . i did apply vacuum to the valve and the diafram dose work. thats the way i bought it. the vacuum advance is hooked up direct to the carb. to a tap on the choke side of carb. no spark delay valve. this thing is a nightmare so far. but i'm making progress with it.

 

For the carburetor to spacer gasket, use the thick kind. They are somewhere between 1/8 and 1/4 inch thick. They must be bought on their own. The paper-thin gaskets that come with rebuild kits are crap. If you have a lot of gas under the carburetor, you might have a leaking power valve, or a crack in the throttle body, although less likely. For the spacer to manifold gasket, use the thick steel-woven gasket. It is very important to use this kind because of the extreme temperatures that the EGR spacer plate sees. Again, the paper-thin gaskets that come in a rebuild kit are completely useless. I always use Fel Pro gaskets.

Carbon buildup in the EGR spacer plate is quite normal; try to clean it out if you can. The EGR valve should run off ported vacuum at the very least. Some setups have a coolant temperature sensor to shut off vacuum to the valve; there are even some setups that run a speed sensor to a vacuum solenoid to shut off vacuum to the valve. If you don't run EGR, you need to install an adjustable vacuum advance to adjust the engine's timing curve. Engines with EGR are set up by the factory to provide more advance than non-EGR engines, so if you simply remove the EGR valve, you'll get pinging on acceleration. You also might need to re-jet the carburetor since engines with EGR run a bit lean by design.

If you are getting sputtering or bogging down on acceleration, you need to check the base timing with a light. You also need to check out the carburetor. With the engine off, look down the throat of the carb and open the throttle. You should see two nice streams of gas shoot at the venturi. Are your problems happening when the engine is warm, cold, or both? There could be choke-related issues as well. Those tests will get you started.

 

i just got done rebuilding the carb. still on my table. i an going to put it in now. the kit came with two gray thin gaskets and one black 1/4 inch thick one with plastic? inserts on it for the carb studs. looks like two pices press together have a woven type pattern on it. that it or is it something else you are talking about ?
thanks for the help to all

 

D8AZ-9A589-B .. EGR Spacer Plate (Motorcraft CM-2831)

D7FZ-9C477-A .. Gasket, Carburetor to EGR Spacer Plate ~ Thick Gasket (Motorcraft CG-473)

D7AZ-9447-A .. Gasket, EGR Spacer to Manifold ~ Thin Gasket (Motorcraft CG-488)

D7AZ-9E464-E .. Gasket-EGR Valve to Spacer (Motorcraft CG-528 or CG-528-A)

D5OZ-9A565-A .. Fuel Enrichment (power) Valve (Motorcraft CE-109)

or

D5TZ-9A565-A .. Fuel Enrichment Valve (Motorcraft CE-117)

 

The thick woven one with the plastic inserts is what you want to use for the carb to spacer gasket. For the spacer to manifold gasket, you will need to purchase it separately. Throw those thin ones away.

 

ok thanks i will get to parts for them. took it for a test ride today. it is a whole lot better than it was but still not right. i hooked up the EGR valve to the vacuum port on the choke side of carb. and have the dist. with no vacuum line to it . ran out of hose . will get some. do i need the vacuum delays for the dist. etc? there are none at all on the engine. it will still bog when i put my foot into it. but if i give it 3/4 gas its ok. i have not put a timming light in it yet. i will in the next day or two.

 

You shouldn't need any vacuum delays for the distributor. Some older emissions setups have them but you probably won't need them. If it's still bogging when you get on the gas, take a look at the accelerator pump on the carb like I mentioned earlier (truck off, look down the throat of the carb and open the throttle). Also check the timing like you mentioned.

 

D5AZ-9B559-A .. Accelerator Pump Diaphram (Motorcraft CM-2092)

C4AZ-9576-A .. Accelerator Pump Diaphram Check Valve (Motorcraft CM-825)

Installation: Cover = Diaphram = Coil Spring = Check Valve = Carburetor

Take care that the coil spring doesn't fly out when you remove the diaphram.

The check valve has a tiny tit on it that wears or breaks off. Most ppl never change it, and it might be the root of your problem. Some of the carb kits don't include it.

 

about every thing has been replaced with new parts . power valve, check valve thing. needle and seat. acc. pump it was soaked in a bucket of new carb cleaner back flushed all passages you name it . the choke is not hooked up the plastic arm on the choke was broken off of it. trying to find a new one with out much luck so far. the dist. vacuum advance does that go to direct vacuum or ported vacuum?

 

You need the choke hooked up. The plastic arm is part of the fast idle linkage; you need it for fast idle but not the choke (however, you need both for the engine to run properly when cold). I found one of those plastic arms off eBay; I think some carb rebuild sites sell them too. However like I said, you can still get the choke plate to function properly without the plastic arm; you just won't have fast idle so you will have some issues. But it's summertime now so maybe you'll have decent luck.

The vacuum advance typically goes to ported vacuum; it depends if you need vacuum at idle or not. I have an old Galaxie that has the advanced hooked to ported vacuum, but it calls for the base timing to be set at 12 (high enough). However on my LTD, the timing is all the way down at 4, but the advance runs off manifold vacuum, so the timing at idle is actually much higher. After the throttle is open a ways, which vacuum source won't matter. I would hook your advance up to ported vacuum at first.

 

thanks i will try the advance ported and non ported and see what happens. i have two choke assy's laying around and each had the broken arms. i will throw on one from a old 85 ford i had with all electric choke.

 

yahoo i got it nailed. well i fixed the problems well 95% any way some of the problem was the PVC hose it had thin tubing on it when engine created normal vacuum the the hose collapsed the other problem other than the carb rebuild was the a past owner put in a fuel filter for a lawn mower no lie had a inside diamiter if 1/8 " gee's why would some one put one of them on a 400 cu in engine ?

 

That's hilarious! Glad to know it's running better.