How many of you still get the misfire like stumble during lite throttle and cruise situations?

I am beginning to think that either I am the only one with this problem or someone found a fix and didnt share thier information or has been dealing with it for so many years now, that it is just excepted as a natural ford thing.


I have been pulling my hair out and flushing money down the crapper for many years now (almost countless). Buying parts i didnt need, each and every time with fingers crossed. Mechanics throwing guess work into it. Match sticks saying burn it up!

I did my truck homework and searched other forums till I finally landed some helpful information.
Decided I have nothing to loose, gave it a try and am at day three without a noticable stumble. Still trial period sofar, will be taking it to get my Maryland Emission testing done on friday and if I pass it will put the icing on the cake of why the hell didnt I think of this earlier.

 

You probably covered it, but did you replace the vacuum lines with rubber hoses? How about replacing the distributor? My truck ran substantially better after changing these two items.

 

I made a restrictor plate to lesson the egr exhaust flow which caused the stumble at cruise. There was to much exhaust gas entering the combustion chamber at low rpms causing it to run lean. This not only corrected my stumbles but also made a difference in over all running condition. Plus being able to keep my egr vps connected and still functioning, my computer reprogramed the new change and did not throw a Cel. Pulled codes koeo and running and still came clean across the board.

 

That's what the EGR does, makes it run lean. It's supposed to make it run as lean as possible but maybe yours is pushing the limits. Mine does stumble, and my EGR isn't working properly, but I just don't care enough to mess with it.

 

So tell me more. This is exactly what i am facing right now in my 91

 

I learned this through another forum so not to steel the credit;

Inorder to make a restrictor plate you will need a thin piece of metal or aluminum atleast 2"x3".
I cut a piece out of the back of a old 6" rain gutter but any flat piece of metal or aluminun will do that laying around the house.

You need to remove the two egr to intake bolts: No need to undo the egr tube to do this. the egr can just be pushed back out from the intake enough to install the gaskets and restrictor plate.

Unplug the vacuum tube to the evp so not to break it. I also removed my evp just to have it out of the way, plus its only three bolts. Thats your choice. If you do just make sure the evp o'ring is seated correctly.


You need to purchase 2 egr valve gaskets, the restictor plate will be sandwiched between them.

Place one of the gaskets over the piece of metal and trace the gasket outer side and the inner side of the bolt holes and just 1 egr port hole.

You can reverse the next two steps if you like; Using a pair of metal snips cut the gasket pattern out of the metal (but not the holes).
You will need two metal drill bits; 3/8 and 1/8.
Using the 3/8 to drill out the bolt holes maked on the metal
and then use the 1/8 to drill a hole in the (center of the port hole) marked on the metal. A small punch will help keep the drill from sliding off mark.

Using a thin layer of gasket sealer on each gasket, sandwich the restrictor plate between the gaskets. I then also thin coated the outer sides of the gaskets inorder to make sure I had a good seal to the intake and egr.

While pushing back on the egr valve to open the gap between it and the intake, slide the top egr bolt into the hole and through the restrictor plate. then do the same with the lower bolt. ((Be sure that the 1/8 hole in the restrictor plate is at the intake opening port)). finger thread them in alittle then tighten them up.

Reinstall the evp and vacuum hose if disconnected.

(Most important step is to remove the positive battery cable for afew seconds then hook it back up so that the computer resets itself and learns the changes).

Time to fire it up and watch what doesnt happen . You have to give the computer about 10 miles or so to relearn everything again.

I wish I would have known to do this years ago!

Check back in and let us know how its going!!!
　

 

Gonna work on this one this weekend

 

Let me know how it goes! I go in for my emission test tomarrow, cant wait to see the results.