Hello Folks! 93 ford e150 4.9l 6 cylinder with e4od trans. Runs good when in park or neutral. Even runs good for first 20 minutes of driving. Then, when in gear, it dogs. I can put pedal to floor and will accelerate very slowly. Also it feels like quick slips or something in tranny ( I don't know how else to describe it). When at a stop with half brake on it lurches, like it's being pushed.
Fluid is full. No check engine lights. I have recently replaced all the major sensors ( before this problem started), like tps, iac, rear abs in rear diff, egr valve, coolant temp sensor.

I looked at this control module (I don't know what it is) that is under drivers dashboard. I was thinking it is the PCM. The board is a little corroded. It's NOT the cruise control module. That is there too but its fine. I even removed just to make sure it has nothing to do with it.

That's about it. I figure must be a known issue. Just not by me. Willing to pay for expert help. Thanks!

 

Did this happen one day or developed over time? Clogged fuel filter or catalytic converter?

Sixto
07 E350 5.4 175K miles

 

I've seen a plugged cat totally shut an engine off after a few minutes of running, I can't recall if there was a check engine light tho.

 

Well, I think it has to do with the fluid getting too hot. I have never experienced "limp mode" (lol) but maybe that's what is happening after it runs for a bit. Because when its cool it runs like a dream. Driving for 20 minutes it starts doing that ******* when in gear. So is that like a blocked passage or something making the trans hot??

 

Even if the check engine light isn't on you need to read the codes.

 

Indeed. I will check those asap and see what they say. Thanks!

 

So, got a 111-System Pass, and a 334-EGR closed voltage higher than expected. If the EGR is the problem, wouldn't the RPM in Neutral be affected as well? This is only ******* while in gear. Put it in Neutral and revs just fine. And when the system is cold it starts and drives perfect.

 

So I tested the EGR and it opens just fine when blocking off the solenoid even while driving. When idle it kills the engine immediately.
And btw this is a new EGR I replace last year about 1,000 miles ago along with most if not all the other sensors. I did all that because there was some idle issues but I have cleared all that up. Thing ran fine for a bit and now it's doing something that it didn't do before.

So it runs fine with hot engine but cold trans but runs like crap with hot transmission. What would make it behave that way? Just completely stumped.

 

I've never seen the trans fluid getting too hot and causing a performance problem. I've tested transmissions as hot as 320°F and didn't run into this problem. I also programmed the "limp mode" as you call it, and it doesn't cause performance problems when the trans is hot. Your problem is in the engine, not the transmission.

 

What if the trans fluid was too full? When it gets hot would it cause that kind of problem. I believe I added a bit too much (didn't read it right on the stick). It was low and I put 2 quarts in. So, could have been that it was low and having issues and then I put too much and it had the same symptoms? I will correct that and see how it works. Cheers!

 

No, that won't cause it, either. This is an engine problem.

 

Ok. It must be the EGR. This what happens though. Drove it for 40 minutes, 55 MPH for 20 of it. Ran fine. Stopped at the dog park and shut it off. Walked dog for 20 minutes. Start it up and it's doing it!
I did notice that it is idling rough as well, don't know why I didn't notice it before and thought it idled fine.
I pulled the vac line off the EGR and there was no change. Meaning it still ran like crap.
But why??
Is it the EGR itself (which is brand new) or is something else? Because the EGR opens when I cover the solenoid. So maybe it is partially clogged? And why does it act up when it's been shutoff but can drive it for at least 40 minutes and not have a problem? Very strange to me but I am not an EGR expert.
It's all very repeatable.
Any feedback is welcome. Thanks!

 

Ok, fixed it! Mainly the Fuel Pressure Regulator. Combined with the heat shield for the EGR tube being displaced and too much heat on the incoming fuel line. I corrected the heat shield and the running rough after driving was fixed mostly. Still had weird performance issues though. Replaced the FPR and it runs like a dream!!!! Thanks for helping me work through it! Cheers!