[383tpimachine]

Does anyone have a 4L80e behind a carbs motor?

I am using an optishift controller and am having a serious bog down issue in reverse. Idle can be set to anything from 600-1200 and when put in reverse it bogs down to 450-500rpm and slowly dies.

Drive does the same if the idle is set around 700 but is completely fine at 1100.

Any idea? To much trans line pressure maybe?

 

[TrannyMike]

What's the motor like. Do you have a big cam in it? :beer:

 

[383tpimachine]

What's the motor like. Do you have a big cam in it? :beer:

baby RV cam for good gas mileage. Ran really bad then found I had a dead plug wire. New wires and it runs great. Good compression across all 8.

I can have the engine idle at 500 with no issues as long as it is in park or neutral. The extra mass in D kills it but reverse is the worst.

 

[woody31]

i would say you need more stall :beer:

 

[TrannyMike]

The idle is too low. I don't have any specs in front of me, but the idle should be around 600-650 in gear I believe. Other motor guys on here will know exactly though. :beer:

 

[woody31]

should be a lil more stall there about 2200 then you can enjoy your cam and combo
but hey i just run a wore out truck motor -what do i knowoke:

 

[TrannyMike]

An RV cam really doesn't lope. That's not the problem. You don't require a high stall converter for that motor. Raise the idle and see what happens. :beer:

 

[383tpimachine]

I have raised the idle. At 1100 in Drive it drops down to 600-700 which is perfect. However in Reverse is drops to 450-500 and surges and keeps trying to die.

I can only think that the trans controller is commanding to much pressure in R versus D. That or since the engine is still fresh hone and new rings hasnt fully seated.

 

[383tpimachine]

An RV cam really doesn't lope. That's not the problem. You don't require a high stall converter for that motor. Raise the idle and see what happens. :beer:

no lope at all. I cant even hear the exhaust with long tube headers true duals and the mufflers exiting in front of the rear tires. VERY QUIET.

Stock stall which is about 14-1600

 

[woody31]

A fresh engine with new rings wont affect your trans issues. Seems your mind is made up. Change your stall converter trust me i have seen this issue before.:texas: