86 2.3L EFI surging under load after 30-45+ driving

[radiojoe]

Hey,

My 86 2.3L EFI 4x4 ranger is surging under load, but only after I've been driving for over 30 minutes or so. For instance, there is a steep hill near my house that I can really only go up in first gear if I start from a stop at the bottom of the hill, it will rev fine all the way up past 4,500rpm before I shift and be just fine. But, after driving for a while, if I do the same hill and drive it the same way, once it hits about 3k rpm the engine starts surging like crazy, making for a very violent ride.

In the last two months or so since I've owned this truck, in troubleshooting this and other issues, I've done cap/rotor/plugs/wires, ignition coil, air filter, O2 sensor, fuel pump (high pressure in line one), and fuel filter.

Any thoughts?

 

[Winger]

Egr

Some one here may disagree with me but I think I had that same problem a few years ago and I believe it was the EGR that caused that. You'd better look into it as far trouble shoot that valve before you change it there not cheap! Just a thought.

 

[St Ranger]

sounds familiar

My 85 is acting the same way, i was told it was a hot fuel delivery problem as it only hasppens during the daytime and when i sit at idle for any length of time, i just started a thread 'hot fuel delivery problem' you might want to keep an eye on it for answers, hope it helps

 

[radiojoe]

Hm I can't find the hot fuel delivery thread. Can someone give me a link?

 

[radiojoe]

Hm I can't find the hot fuel delivery thread. Can someone give me a link?

Nevermind, I found it.

So, turns out there was so much carbon build up in the hole that goes to the EGR valve from the upper intake that really no air could go through at all. I cleaned that all up and have it back together, and now it's just sucking massive amounts of air through the valve right on start up. But I'm not really sure what it should be doing- does that sound right?

 

[phatcap]

this should tell you all you need to know about the egr system...

http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/FordEGRSystem.htm

check it out