The past few days ive had this issue. In the morning i go and let my truck warm up all the way and leave for school, it runs fine all the way out of my neighborhood but once i turn onto the road and try to accelerate, the rpms drop and it almost dies. It will die unless i throw it into neutral and hold the gas all the way in witch case the revs will climb very very slowly, it take around 15-20 seconds to climb all the way up. then it idles fine and if i hold it at 2000 rpm and put it in drive it will take off and run fine to school. The only other thing i notice when this happens is when the rmps drop the brake gets really stiff like i have no vacuum to the brake booster, when they finally climb back up the brakes return to normal. I cant figure why it only does it in the morning, but not after school or befor or after work even though the temperature is the same, 30-40 degrees morning and night. If anyone has some input or any ideas please let me know,
Thanks.

 

Don't know what carb/engine you have but it sounds like an accelerator pump issue.

With the engine OFF and the air filter off, blip the throttle whilst peeking down the carb's throat. You should see two squirts of fuel when you do this.

Are the floats set correctly?

Brake booster going .....when the RPMs drop the engine isn't turning over fast enough to create a good, healthy vacuum. Tha't's why your brakes feel like a lead balloon. RPMs increase, so does the vacuum and you have brakes again.

Results on the squirter test?

 

This sounds a little bit like the egr is sticking, and not closing when idling. Maybe a bad vacuum valve or maybe a bad egr valve, is the egr still functioning?

 

Maybe it just doesn't cool down all the way during the day, like it does overnight.
Could you get a whiff of the exhaust when it does this, and see if it's rich or lean?
And the problem just popped up one day, but it was fine before?

Does your choke have the wire connected to it? Does it have the hot air tube which leads from the choke to the manifold?
How about the heat riser which runs from the exhaust manifold to the bottom of the air filter housing?


Nice looking truck though.

 

I will try to answer all your questions at once, its a 360 with an almost new 600 cfm edlbrock carb, the choke is connected and works fine, i havnt looked down the carb to see myself but when i blip the pedal it seems fine, i will look at that when i get home from school today, is the egr valve the brass vacuum deal with 4 ports on it, behind the carb on top of the intake? if so then i have 2 of the ports plugged, but when i remove then the idle goes crazy and i can definitly hear it so i assume its working, all ik about it is that it was for all the new emmissions stuff they started implimenting then. My truck does not have the heat riser, nor the hot air tube to the choke. I put a new to me motor in this truck around 6 months ago and problems like this just pop up one day, i fix them and it runs great for a few weeks, then boom another problem
edit: i have no idea if the floats ar set or not, nor do i know how to set them, i took it too a shop to put the motor in and they put the carb on too, maybe they did maybe not, as for fuel mixture i have been dealing eith trying to get it right but i have symptoms of both lean and rich so i went eith the 1-1/4 turns out standart and that seemed to help

 

Maybe post up pics of the top of the engine, with the air filter removed. Did the problem pop up when the weather was colder than it had been before?

As long as you have the proper electrical connection to the choke, then you should be fine with an aftermarket carb/choke. (And that's 12V DC+ you want going to the Eddy choke - not the AC voltage the original Ford choke might've used.) The OEM Ford chokes do need the hot air tube though.

If you're running the original Ford air filter assembly, it might not be a bad idea to add the heat riser and stove. I think the McParts stores have generic kits for this - at least in Cali, I've read. Of course you would need a Temperature Controlled Vacuum Switch (which threads into the T'stat housing or coolant passage in the intake manifold) to properly control the valve in the air filter snorkel.

 

Here are some pictures, and just checked the accelerator pump seems to be fine

 

Dont think its part of your problem, but are you choosing not to run the vacuum advance off your distributor ? Also your running the PCV hose to the rear, must be in the back of the manifold which should be 'manifold vacuum' anyways, but ive always ran mine to the front port of the Carb ? Just thinking out-loud, i have a very similar setup....

 

Yeah, the lack of vacuum advance could cause it to fall on its face. I'd also check/replace the vacuum hoses. Some of them look original, and rather oxidized/deteriorated.

That MrGasket logo on the oil filler breather looked like a chevy bow tie at first...

 

A bad distributor was my last problem, and boy was that a trip when the oil pump shaft fell down into the oil pan. thats distributor is new and the old vacuum advance was no good so when i put the new one i didnt know wether to run it to the carb or intake, some people say one some say the other. and the pcv valve is running into the rear of the carb, not sure where else i could run it to. let me know where i should run the vacuum advanced to and ill hook it up, thanks.

 

Ported is usually best. There should be a dedicated port on maybe the passenger side of the carb for ported vacuum. A ported vacuum port will typically be higher on the carb body than the 'manifold vacuum' sources.

You can try ported and manifold vacuums and see which one works best. And your vacuum advance servo might well be adjustable with an Allen wrench through its vacuum port.

 

PCV should go to the front middle (larger nipple) Edelbrock says

"Can I run my PCV line to the rear of the carburetor?"
"We do not recommend routing the PCV line to the rear of the carburetor. We recommend that the PCV line go to the front, if you have power brakes, they go to the rear."

Yet I also have my brake booster plugged into a tree on the rear of my intake and it works fine, as long as the rear port on your Brock is plugged.... but your choice there....

I didnt think the vacuum advance could affect your timing/carb tuning enough to cause the symptoms you describe, but im no expert.... If you do run your vacuum advance it will plug into the front left port, left of the PCV hose...... Both easy cheap fixes, that you can test out and see how she runs....

How did you manage to fit an air cleaner over the straight fuel inlet ?? I had to get the 90 degree elbow kit for the fuel inlet which I hate because then my fuel line sits right on top of the intake heat ..... The only thing I dislike about the Edelbrock is the fuel inlet design and location.......

 

If you use an "Edelbrock" air cleaner it has a black spacer that raises the air filter high enough to clear the lines. Mine is just like his here, goes straight into the carb

Definitely plug that Vacuum advance in when you get a chance. AND before you plug it in, test it to make sure it doesn't leak. Just put a hose on the vacuum advance canister, and try to suck air through it, it should not allow you to pull air continously, it should hold a vacuum. To plug it in to the carb, run a vacuum hose from the vacuum advance, to the small vacuum pipe on the front of the carb just to the left of the large pipe on the front. That is the ported vacuum, which is pretty typical to use for advance.

That multi port brass color thing is just a vacuum tree to allow multiple items to all connect to manifold vacuum, it's not your EGR valve. I can't even see an EGR valve in your picture, they are usually on the back side of the engine, if you could get a photo of what's behind the carb that would help.

What kind of intake manifold is that? Is that an Edelbrock intake? Should double check if it's Non-EGR or not.

In one of the pictures it looks like there is a vacuum hose sticking straight up not connected to anything. What hose is that?

Everything else in the pictures look OK.

Two more things to check:

1. Check for possible vacuum leak in the brake booster. That's a huge hose so if it leaks you won't be able to run the engine worth a damn and also your brakes won't work very well
2. Check that your fuel pump is working decent

 

It is an edlebrock intake, and i know my old motor did have and egr not sure about this one. the vacuum hose not connected is the second port on the transmission modulator because i didnt know where to connect it either. but tranny works fine without it. i did the propane check for vacuum leaks but didnt find any. my fuel pump does struggle, works fine for 30mins then starts to fall behind planning to get a new one soon. ill be sure to fix pcv valve and connect vacuum advance when i can

 

Propane test is good but it wont show if the brake booster itself may be leaking internally. Not sure the best way to test that though other than removing the line and plugging it which of course would give you manual brakes...