OK I've been fighting this issue since I installed my 80E.
Had the Sonnax line to lube installed then sent converter back to be loosened up.
Some back round info. When I 1st installed it I used the stock rubber mount from my Th 350.
I also used a GForce xmember . These 2 things made the trans lean too far back and when I 1st fired it up, it was making a knocking sound.
Upon further inspection, I found the rotor was hitting the cap which I later found out why.
The cap was knocked off from the dizzy hitting the fire wall.
I shimmed the trans up enough so the cap would go back on and bent the rotor back inline and took it for a spin.
Back up u few.
When I went to take it out for it's 1st ride it would stall putting it in reverse.
Especially when it was cold.
OK, back to the "test" ride.
I get it on the road and a mile from my house it starts backfiring really bad then dies.
I get home and found out why..
1st pic happened on 1st start, 2nd is when it died.
I wonder why?
DUH!
So the converter went back as I mentioned after the LTL install and it was still a little funky when cold but fine when warm.
So still wanting it perfect , I took the fitech off this weekend to see if I screwed it up with the backfiring from the 1st test ride.
Well it stalls the carb right out when the engine temp is 180* unless I footbrake it but will die when I lift it.

I guess My question is....is there anything internally or in the programming in my compushift that could be doing this?
When the converter went back they said it look perfect and when the trans guy put the LTL valve in, he said the fluid look good too and nothing was in the pan.
Could it be the converter is still too tight for my cam? it was a 5C now a 6F.
I have a trans PSI gauge I can put on it also to see if "maybe" the pressure is too high or something.
Maybe the banjo fitting for the center support is too long and blocking flow from the cooler?
The trans has never run hot.
Sitting behind school bus it went to 175 once but once moving again goes down to the 145/150's
MY next step after putting the gauge on it is to yank my intake off to see if there's a huge vacuum leak from the valley area that happened from the backfiring.
Any help would be REALLY appreciated!
This is really pissing me off as I love the OD!
Sorry for the long post!

Thanks,

Chris

 

Well I'll post my psi readings.
Looks like 60psi at idle and a tap of the throttle it whips up to 175+
I still have the carb on but it won't stay running with it on. The tb FI learned it's way around it. Well almost.
I'm going to rip the intake off and replace the gaskets.
It's not leaking from the outside. It has to be from the valley area.
That's the only thing I can think of that "could" be pulling it down and stall.
Maybe the distributor got messed up too.
It's either that or the converter it still too tight for my 262/269 dur @ .050" SR

 

Remove & Plug the PCV valve if equipped, With the engine idling....Spray some carb cleaner down into the pcv gromment or oil fill hole.....If RPM changes a lot, The intake does have a vacuum leak in the lifter valley.

 

I tried that but I think the girdle blocked most of it.
I can set the Idle at 1500+ and it still will die with the carb.
This is really pissing me off.
Even with the FI, The IAC will keep it running "most" of the time but occasionally stall.
Never had these issues with the 8" treemaster....but like I said as you can see from the pictures, It was backfiring pretty bad before it died.
Idle is my only issue. WOT and part throttle are fine.

 

Ok, took the carb back off and while it was off I used my bore scope and checked the runners of the intake.
Before I did that using my led flashlight So I could see down the rear 4 runners without it too.
They appear to havel what looks like little bumps being pulled up into the runners from the bottom and some from the sides too.
Maybe my buddy put some RTV there prior to intake install OR the gaskets breaking down and being pulled into the runners.
Only 1 way to find out!

 

That's a huge cam @ .050, needs a lot of stall-sometimes you can fatten up the carb to help @ idle, maybe try a little smaller idle air bleeds, or if you have idle screw control, rich it up-of course it will stink with fuel, lol
What is your idle vac, prob low

 

9/10" at best.
I already sent the converter back once I'm hoping it's my intake gaskets that are causing all the issues.
If I change them and it still persists, It will have to come out AGAIN!
That would really suck tho!
It is better with the FITECH TB FI on it as the IAC try's too compensate for it but it's still will stall every once and a while.

 

I don't know much about Fitech, can you speed up the IAC ability, I know on the Holley HP you can adjust the speed
Have you tried diff. timing at idle, if you can adjust to get a little more torq. at idle it might help. I cant remember if the CS controller can adjust the pressure down at idle, been a while, I know in the CS 2 there were advanced tables. On one of my 80E's I was getting converter drain back, you didn't go anywhere until it filled, was like a really high stall conv. I replaced the valve with one of the Sonnax ones.

 

Yeah, I'm waiting to see If there is an update for the FI.
I think it needs to respond quicker and maybe a little higher in the steps.
Sometimes it will just sit at 140/150's (steps) when it "could" go as high as 255 steps and it's well below the target rpm.
I'm waiting to hear back from FITECH to see if there is an update for it or not.
Another member is trying to give me files to load on it to adjust the gain.
He says this may help with it in how quick it responds.
I still feel that it should be able to run with the carb too tho.
It still may be it's STILL just too tight at idle....but before I condemn the converter I want to rule out a vacuum leak from the lower valley area 1st.

 

Well I was able to drop my car down today. Been REAL busy with side work and my sons 406 is going to the dyno tomorrow.
I raised the LD2 boost back to 10% (stock setting for compushift) and the pressure goes right to 125psi in reverse.
Unfortunately that's all I had time to do.
Maybe tomorrow after the dyno...