I bought a motorcraft 2100 stamped 1.21 on the side number D4 AE GA, to replace my broke 2150. Anyway I bought a kit from adavance and it idles great now, way better than with my 2150, anyway problem now is after I rev it up it wants to die when it comes back to idle if I hurry and tap the gas one time it won't die. Also I noticed that my glass fuel filter had hardly any gas in it. Shouldn't the fuel pump be keeping it close to full?? Do you think my pump is going out?? Would that cause it stall when coming back to idle. Thanks for all the help.

 

When it wants to die after coming back down from a high-rev, that means the fuel bowl level is too low. There could be two reasons. The first reason could be your float height is off. The other reason could be the fuel pump is too weak. The fact that you aren't seeing much gas in the filter backs this guess up.

You will probably also find your truck stalling when you try to pass someone on the highway or if you take really, really sharp turns. Also, you might want to check your oil and see if you smell any gas in it, or if the oil looks runny or if the crankcase is suspiciously overfull. Gas in the oil is a tell-tale sign of a dying fuel pump.

 

I haven't measured the float level wet with the top off the carb. I just set it to the correct dry level of 7/16. My fuel pump is the same one that has been on the truck since 1989. I'll smell the oil when I get home, I checked the oil level saturday and the consistancy looked normal but I didn't smell it.

 

I checked last night and the oil does smell like gas, but it looked fine. I guess I know what my next little project is. Thanks for the tip.

 

If you need carb parts, the one you bought: D4AE-GA is from a 1974 Ford LTD, prolly with either a 351C or 400 engine. Make sure to take that carb number with you, then the parts person can give you the correct parts. That carb (by the part number) was never used on trucks.

 

Thanks, I did go get a kit for it and I made sure I had the number. I didn't know what it was from because I bought it from a guy on the south side of town that rebuilds carbs and he had this one just laying around waiting to be rebuilt. I gave him $10 for it and paid 20 for the kit at napa.

 

Pretty much any shop you go to will require the numbers before they can sell you a kit. I've never heard of a shop that sells carb kits simply by model and year alone. Any two identical vehicles could have completely different carb numbers because of factors like elevation and emissions. As a side note, just because the carb numbers don't trace to the vehicle doesn't mean the carb isn't original, as Ford mixed and matched carbs from time to time.

Before you spend the money on a new pump, I would pull the air horn off the carb with the engine idling and do a wet-check just to make sure it's really the pump and not the float height. The little ruler in the kit can be used for that as well.

Just a couple helpful tips when/if you change that pump; the pump will be a lot easier to get off if you make sure the engine is on TDC before you start working. Also, anytime a mechanical fuel pump fails, it's good measure to change the oil afterwards (especially if you smell gas in it). I had a fuel pump fail on a 351W last year and it pumped over a quart of gasoline into the crankcase before quitting completely.

 

There is no D3AE or D4AE-anything in the 1973/79 Ford truck parts books~I know because I checked, and I have the books.

 

Okay one quick question that just hit me. When I set the dry float level, it was to the specs for my truck and engine combo 77 with a 302 on the spec sheet 7/16" dry. Since apparently this carb came from an LTD with a 351m or 400 should I have set the float level to those specs??? I didn't even think about this till right now. They may be same I didn't even look at the LTD specs because I didn't know it was from an LTD, but just in case they are different.

This may also help someone else out that has changed to a different carb from a different model.

 

LTD specs are 7/16" as well. I know because I own a '73 with a 400 in it and it's 7/16". My '77 has a 351W and it's 7/16" too. You should set the float based on the vehicle the carb is currently on, so you did the right thing, as long as the venturi sizes are the same. The only other difference would be the jet sizes. You really need to take the air horn off the carb and see how much fuel you have in the bowl.

Also, NumberDummy - I wasn't saying his carb came off a truck; it's obvious it didn't. It would have been D4TE if it did. I was just saying that whether he says his carb is from an LTD or a Ford Truck makes no difference to the parts guy because he's going to ignore what model name you give him and he'll just ask for the numbers off the tag.

 

Well the venturi's are different, I guess because this one has 1.21 stamped on the side and my original has 1.08.

 

It's a larger CFM. You now have 351CFM vs 287CFM on the old one.

 

Okay, I know its been a month since I posted to this. But I got the dying when revved problem fixed. NOW!!! After the truck warms up and the fast idle kicks off and the choke is open when I put it in gear it DIES!. I have turned the curb idle screw to where when its in park it seems like it is idling too fast to try to keep it from dying when I put it in gear, but no matter how fast it idles in park when I drop it into gear it dies. Any ideas on this problem???????????
Thanks

 

Sounds like your fast idle is coming off too quick or your choke is opening up too early. Are you using both steps of the fast idle cam? Remember - when you first pump the gas in the morning to snap the choke shut, the fast idle screw is on the highest notch of the cam. The next time you tap the gas, the fast idle screw should drop to the middle step of the cam. After the choke is all the way open and you tap the gas, the fast idle screw will drop completely off of the cam and you will drop back to curb idle.

Here is the best way to properly set up fast idle on a 2100. With the truck cold, go out and pump the gas so that the choke snaps shut. Then depress the choke pull-down diaphragm all the way so that the choke is in the pull-down position. Hold the pull-down diaphragm down like that with one hand, then use your other hand to tap the throttle open. The fast idle cam will fall. Close the throttle, then let go of the pull-down diaphragm, then look under the choke at the fast idle cam. The end of the fast idle screw (it might be a tab, depending on what type of 2100 you have) should be on the middle step of the fast idle cam, lined up with a V mark on the cam. Finally, open the choke plate all the way up with your one hand, then open the throttle with your other hand, close it back up and let go of the choke plate. The fast idle cam should be completely clear this time around.

If these don't line up, you need to adjust what is called the fast idle index. There is a little hex screw in the choke linkage that controls this. Once you get the index dialed in, you can dial in the fast idle speed (this is the screw on the back of the carb at the bottom of the choke linkage). Then you can bring your curb idle back down to normal.

 

Sounds like the mixture screws are too far in and it is running lean or you have a vacuum leak.