2.8 not running right.

[bonedoc]

Okay, here's an update, checked all grounds around the distributor, vacuum lines and vacuum modulator on trans. all seems good.

The issue is again the truck bogs and hesitates. There are times we
here it will run fine. Then others where you step on the pedal and it bogs and hesitates. Then usually if I mash the pedal to the floor it will down shift hard and accelerate then when it upshifts it bogs again. I've tried driving with it in drive instead of overdrive and it doesn't change it. It seems like ytou press the pedal and it will hesitate, bog and then slowly accelerate, other times it seems like it surges. Also when on the pedal if I back off a little on the pedal it will all of a sudden surge with power....kind of like a sweet spot in the pedal. The only thing that hasn't been replaced on this truck is the carb. Could the carb just be shot? Any suggestions? I'm looking at the holley 350cfm 2 barrel, you can get the auto choke conversion for it and they also make a throttle position senso for it that can be wired in. Has anyone tried this? It is driving me crazy...tired of the truck not having enough power and get up and go to get out of its own way. I mean it never was a race car but it still could move along okay.

Thanks...
Happy Holidays to all

 

[NMB2]

duraspark it.

 

[Bronco_Chuck]

sounds like carb issues to me. the first thing that came to mind when i read it is it sounds like your electric choke is set wrong. the only other thing that comes to mind at the moment is the acellerator pump being bad, and as for having power to get out of its own way, ive never owned a 2.8 that could do that.

 

[bonedoc]

To me it seemed like the carb too and I'm considering the duraspark conversion. The vehicle has the A4LD trans so I know that could be a problem. Believe it or not when it runs right it gets up and goes. It has headers and a open 2 1/2 inch exhaust. Figure opening the intake will improve alot of things. Any suggestions for swapping the carb...which one and for the duraspark, are the parts easily accessible and available.

Thanks

 

[skippy]

To me it seemed like the carb too and I'm considering the duraspark conversion. The vehicle has the A4LD trans so I know that could be a problem. Believe it or not when it runs right it gets up and goes. It has headers and a open 2 1/2 inch exhaust. Figure opening the intake will improve alot of things. Any suggestions for swapping the carb...which one and for the duraspark, are the parts easily accessible and available.

Thanks

http://www.therangerstation.com/tech_library/2_8Duraspark.html

 

[cammeddrz]

what is your compression? low compression will do funny things that look like your symptoms

 

[NMB2]

To me it seemed like the carb too and I'm considering the duraspark conversion. The vehicle has the A4LD trans so I know that could be a problem. Believe it or not when it runs right it gets up and goes. It has headers and a open 2 1/2 inch exhaust. Figure opening the intake will improve alot of things. Any suggestions for swapping the carb...which one and for the duraspark, are the parts easily accessible and available.

Thanks

mine pulls my truck on 40's. I use the motorcraft 2150 and yes the parts are easily accessible and available. I will be selling mine soon as I am going to do a 4.0 swap.

 

[bonedoc]

Compression is fine, motor is a jasper rebuild with omly about 20,000 on it. How do I find out what carb is on mine? Where can I find a 2150? Will it work with an A4LD trans? Do I have to duraspark the truck to do that swap? Sounds to me like the carb and a duraspark conversion is the best way to go.

Thanks

 

[bonedoc]

Hey guys...looking for the all the parts to do a duraspark...anyone know where to get them? I was searching out all the part number from the conversion page and kept hitting dead ends. Also...probaly going to just use the holley carb since it says that one is good also..as well as readily available.

 

[cammeddrz]

Compression is fine
Thanks

without a test? man i wish i was psychic like that when i needed to do a comp test on my '97 camaro (the book quotes out 10 hours for a spark plug change) that one's engine was less than 3,000 miles old when you are stumped after checking the conventional/predictable things sometimes you need to start checking unconventional and unpredictable things. on a bII a comp test is pretty easy, (a half-hour at the most) and ruling it out won't hurt, and it will give you a chance to look at each and every spark plug for signs of too, rich/too lean codition, presence of oil etc.

as far as carbs go a pinto carb (i don't know the model #) is the way to go. i have one for sale too. ($30 I did a v8 swap)

another thing to check is to start up the truck and spray carb cleaner all over the intake manifold (avoiding getting it in the intake) you're checking for vacuum leaks.what you are looking for is as you spray it if you hear the engine idle change there is a leak. there is a lot of vacuum hoses/ports on those things, the one vacuum port behind the carb has 6 hoses coming off of it. thats a lot of opportunities to have a hair-line crack in a hose or something . i just went down and got a pack of assorted vacuum caps, and a 3/8" male pipe-thread plug and pretty much capped all the vacuum hoses except the brake booster and i think the dist, it was a loooooong time ago that i did it. and it didn't seem to affect my passing of emmissions tests

 

[bonedoc]

Sorry, I should of clarified but we did a compression test and all was good. Looking at what I'm reading and seeing.. it looks as the best to do is carb and duraspark conversion. While I'm at it, though we found no obvious vacuum leaks just going to replace all lines while there. Just want to get all parts and be sure of the procedure because I need the truck pretty much every day so I need to be able to do the swap and get it finished and running.

 

[martin]

Did you check the vacuum hose that connect to the powr valve?, it might be cracked.

 

[NMB2]

I want to start by correcting myself, its been years since i did the DS swap. I currently use a motorcraft 2100, You can tell a 2150 from it's 2100 ancestor by the little rods that rise and fall in the venturis as you work the throttle. all the parts can be purchased new. Distributor for a 78 Pinto w/ 2.8, the duraspark igniton box, a new coil and a 2100 carb. the carb you have now is probably the 2150, which i replaced because I personally think they are troublesome from my exp, but you will find alot of people that love them, mainly street people though, not offroad. My carb came from a 78 mustang 302. the motorcraft carbs are known for being the best usually, and i can attest to them, I havent had any problems with mine for the coming up on 4yrs ive run mine. I also use an electric fuel pump.

Incase you have any issues finding parts, I have an extra DS dizzy iirc and duraspark box that you could rebuild. I dont need them so i would let them go really cheap if you're interested. the parts currently on my truck though i purchased brand new, and thats what i would do as well if i were you.