Stalling issue I can't diagnose

[BigMeatyClaws]

1985 2.8 with the 2150A motorcraft. I had a hesitation/stalling issue when I accelerated. The engine would die if I hammered down, but it was driveable and it would idle, albeit rough. I pulled the accelerator pump diaphragm and the rubber part was shot so I replaced that. I also replaced the PCV hose as it had a leak. Now if I hit the gas at all it immediately dies. Still idles the same. I checked the carb with the air cleaner off and gas was only squirting out one side. I cleaned out the other and it comes out of both now. So I have fuel at acceleration. Brand new plugs and wires, and coil. And it dies with any acceleration now. Any help appreciated

 

[RonD]

Did you plug the Vacuum advance back in?

You need two changes to accelerate, extra fuel(accelerator pump) and a change in spark advance
The stalling can indicate an issue in both or either

Engine could be flooding out if there is too much fuel added


Yes, the bits of rubber from deteriorating diaphragm clog the passages

 

[BigMeatyClaws]

It seems to be flooding out. I didn't think I removed the vacuum advance when I was working on the diaphragm, but I will put that at the top of my list to check. Thanks.

 

[RonD]

Good read here on your 2150 carb: http://grantorinosport.org/bubbaf250/carb/carb02.html

Click in the "Next" link at the bottom of each page

Is the Choke plate working?
If its not then that could cause stalling and flooding if its not opening all the way

 

[BigMeatyClaws]

The plumbing and wiring to the choke was removed by the last "mechanic" who owned it. So I need to find that next. I've got it set wide open since it won't adjust on its own now. If it's too cold I use a wrench to hold it down until it warms up.

 

[RonD]

Just add a manual cable for the choke

But if its set as open now then that OK, but it will be finicky for the first few minutes after cold start, longer on colder days
Thats just the nature of gasoline, the colder the temp the less vapor it has, so the more choke you need until intake and carb heat up and warm up the gasoline

 

[BigMeatyClaws]

I can't find a port that's open. Hoses look "wrong" I think because of the emissions delete done by previous owner. Where should the port be? Also, can't find any hose running to the distributor? Although I admit I'm new to carburetors and vacuum systems. Attached comes out of carb and goes back to the same area? Today I can accelerate but it still hesitates and backfires, just doesn't die.

 

[RonD]

Look here: https://www.therangerstation.com/tech_library/images/2_8Durasparkdistributor.jpg

If you don't see that gold part with the vacuum port on your distributor then you have a TFI spark system, no vacuum advance, its computer controlled "load advance"


Looks like your PCV Valve hose is not connected to intake/carb base plate???

 

[BigMeatyClaws]

Is that supposed to be underneath the cap? It's hooked to a port on the back driver's side.

 

[BigMeatyClaws]

This is where it is attached. All of this is as I got it, no idea if any is right.

 

[BigMeatyClaws]

Could the TFI failing cause this? I thought that was more of a engine gets hot and then it won't run type of deal.

 

[Man]

On my 2.8, the vacuum advance is hooked to a different place, passenger side right under the choke. It could be the port its in now only supplies constant vacuum, but you need vacuum to increase with throttle. I might also be running a different carb, check your schematic.
This doesn't seem like TFI from my limited experience. Shows how much I know.

 

[BigMeatyClaws]

It is tfi. I'm gonna try a carb rebuild tomorrow. Then I guess I'll hunt for vacuum leaks.

 

[BigMeatyClaws]

Rebuilt the carb and plugged some ports that were open. Now my fuel bowl is overflowing. Gotta love working on vehicles. I think I put the fuel filter in too tight so I'll try fixing that.

 

[franklin2]

Fuel overflowing could be caused by a small piece of dirt under the float needle. I have had them overflow on me, and it was because of a small chunk of rubber coming off a new fuel line I installed. If you are careful and have a magnetic screwdriver, you can pull the top off the carb while it's still on the engine and have a look.

Sounds like your engine is still original, but messed with. The 2.8 was originally computer controlled, which is why you have all those wires and the TFI distributor. There is a special procedure to set the timing. If you do not follow this, the timing could be retarded and give you a stalling, no power problem. If you really want to straighten this thing out and get it running good, you need to go buy a rebuilt distributor for a 79 pinto or mustang with a 2.8, and install a duraspark II module or a HEI module to go along with it. You will not believe the difference it makes in how it runs.

The 2.8 is just like the 80's 300 six in the big trucks. Ford put a computer controlled carb system on it, and that is ok as long as everything works. When something goes wrong, it can ruin a otherwise good engine. You first have to do a lot of studying to figure out how it all works, and then you have to be a detective and find all the parts to work on it, some are not available new anymore. I took the path of least resistance, and converted mine to a conventional ignition system.