v6 weak

[martin]

It sounds like the ignition is not advancing. try pulling codes to give you a starting point. I'm running 33's with 4:10 gears and it performs just fine. I am durasparked though but it performed reasonably well with the factory setup.

 

[Forcus]

The emissions equipment in and of itself will not likely cause you to not be able to maintain 55. I'd first check to make sure your compression is up to specs. My truck runs decent but spews oil smoke out of the dipstick hole. Minimum spec is around 100 PSI, mine is 75-85 PSI. This is enough to cause low power, hard starting, etc.

If you are not using oil, and you have no obvious mechanical problems (also remember the valves are manually adjusted, and also a check of the timing chain, by using the distributor), I'd look to fuel and timing. This is where many people toss the emissions equipment and I can't blame them as the system is hard to diagnose and relatively complicated, and parts are not readily available (new). Not saying you can't make it work perfectly, but if its a driver you have very little time to diagnose.

Most people in this boat convert to a 70's electronic distributor and a same-era Duraspark box, as well as a Motorcraft non-feedback carburetor. Please note that you can take the feedback carb out of the loop and convert it to non-feedback or keep the EEC IV ignition and use a standard carb. This will eliminate some wiring and hoses.

Personally, the very best setup for a carb'd 2.8L would be a remanufactured (a GOOD one... not a junk piece) Motorcraft carb tuned with a wideband and using a modern high flow catalytic converter that does not require air injection. For ignition I would use a brand new Duraspark and new 2.8L aftermarket distributor, and possibly replace the Duraspark with an MSD / Crane / Mallory ignition box.

 

[85_Ranger4x4]

If you are not using oil, and you have no obvious mechanical problems (also remember the valves are manually adjusted, and also a check of the timing chain, by using the distributor), I'd look to fuel and timing.

The 2.8 has timing gears, no chain involved.

 

[Forcus]

The 2.8 has timing gears, no chain involved.

My fault, and thanks for the correction!

 

[josh-the-ranger]

Hi all thanks for all the helpful comments.

I changed my exhaust to a cherry bomb and rebuilt the carburetor put an new oversized air filter(other one plugged solid), new plugs, runs awesome. one problem though the electronic choke doent work so i turned it all the way back, so i have no choke.Now in the colder weather it likes to stutter in lower rpms, i have a manual carb im gonna be putting on for this winter. Another thing i noticed is that in third gear i can go up to 70mph, why in the world did they put a five speed in my truck when i dont even need fifth? i always cruise at 55, 60 in fourth gear and im getting 18.5 mpg on 31's.

 

[85_Ranger4x4]

Because the truck came with tiny tires stock, like 205's or 215's, it should say on the sticker on the drivers side door what it came with originally. My 235's are even oversized, but filled the wheelwells nicely before I lifted it.

 

[josh-the-ranger]

Oh i see, thanks for clearing that up.

 

[Forcus]

For the gearing your truck had, and the tire size stock, and the power range, the factory trans was probably the most efficient setup.

With your bigger tires and low power (age, wear, etc), 4th gear is evidentally what works the best. The bigger tires serve to lower the RPM for a given speed, which can take you out of your power range. A gear swap would likely bring you back to having a usable 5th gear, but, it sounds like you have other engine issues to work out right now.

I'd advise either getting a new Weber carb conversion kit (~$450 from an online supplier) or an Offenhauser intake and a Holley or Edelbrock carb. From what I've read, the Weber is a bit more tractable in daily driving. But if you have other issues, or the wrong gearing for your setup, you may not see any advantage.