So as some of you may have read over the last few months, I have a 1991 ext cab F250 7.3 IDI n/a 4x4 with the E4OD. The trans has seemed weak to me and a bit inconsistent. After FLPS adjustments (1.23-4.18v), all connectors cleaned and greased, oil/filter changed, and MANY posts and questions...
This is where I am;
Ran codes yesterday (3 times) with none showing. Also the trans oil is just as red as it was the day I changed it. But even with the 3.54 gearing, I still feel something, somewhere is weakening the performance.

On a wet day it wont turn the tires, not in gravel or dirt. Put on a slight grade, it will stall at about 1200rpms, no movement. Slight pressure on brakes will hold the truck at a standstill.
When COLD;
*it has a substantial delay before engaging reverse (25 sec) and then only moves slightly, then after about 10 more sec its fully engaged. Forward is delayed too, but not enough to write home about.
*1-2, 2-3, 3-o/d are all smooth and within expected patterns
*stronger feel when cold also
*LU/UL "feels" as I understand it should

When @ Operating temp;
*Delay is nearly gone
*1-2 is very hard most of the time, smooth other
2-3, 3-o/d is still smooth
but patterns are not as consistant
*LU/UL still feels Normal

So at this point I am just very VERY curious. I will mostlikely drive the truck until is gives out bc it does get down the road and do what I need for the time being (also money isnt free). I would just like to know if its a TC, pump, clutches, etc... so I have an idea of cost involved later on.

Thank You as always for reading, and helping.

 

That sound more like a lack of power due to injectors or pump to me.

 

That's possible! I haven't delved into that area yet. It's my next area to look into. I put a new lift pump on it Sunday and it seems a little better. Got a new wireing harness for the right side comming tomorrow, it may be loseing voltage at times causing the inconsistent shifts... I'll hopfully know by this Friday.

 

In relation to the injection, that shouldn't be the problem. IIRC you can completely unplug the FIPL, the trans will go into limp mode, but shifting into R and D will should still be quick. You sir have an issue in your pump end of the transmission. Has is ever been rebuilt? Might just need a trans flush; something is lowering your pump pressure causing the huge delay and other problems. Reason it works better warm is because the liquid is thinner and flows easier.

 

Thats what I wanted to know was trans pressures. But don't have a way to check it here. Also some one suggested a faulty valve in the TC? Could this cause the low pressure also?

The previous owner said the original owner had the tranny rebuilt... But no idea to what extent, by whom, or if it was even ever done.

 

Replaced harness on right side. Old one was in very bad shape, overdrive light had a faint glow and tach quit working. After replacing, nothing's better.

So... Trans shop? In over my head?

 

Ok... Got the issue solved. (Bad relay)

So with that, I am going to take the truck to a buddy's shop to let him see what he thinks. It's either trans or motor performance or just a combination of the two. Either way I'm going to let someone else try.

I'll post what I find out. Thanks guys