Hello Guys, Well here is one that i need some help with.
If i am going down the highway and i put the gas pedel all the to the floor, the 4 barrels will kick in and the car will start to take off.
Then it will disconnect from the transmission and revs way up. If i only put the pedel maybe 75 to 80% down it will stay connected and take off. I don't think that it doe's it from a stand still.Only when i am going above say 25 or so. Is it the linkage from the carb to the trans, or maybe something else. any help would be nice. Thanks Neal

85 Z28
R4700 Auto Trans.
305 ,carb, no ECM

 

this belongs in tranny section, BUT...

If it's an auto then you might have a pressure issue. If the pressures in 4th gear are not what they need to be, then you are overpowering your clutches and they are slipping appearing to have "disconnected". If you let off the pedal a bit, does it catch again?

You need 2 things,

1) A pressure gauge ont he tranny
2) A temp gauge in the tranny pan

You need to see what the tranny is doing. Check your fluid level (while the car is warm and running, not cold and off like oil) and see where it is.

You really need to see the temps and the pressures. Your converter might be broken or worn out so it isnt creating a fluid coupler and not giving the power to the tranny.

If you have a lockup switch then you are in 4th the tranny should lockup automatically, if you are in 3rd then you need to provide a 12v source to the tranny to lockup the converter.

If the same problem happens when the converter is locked up, then its the clutches in the tranny. If it doesnt doo it when the converter is locked up, then its the converter.

To see if the converter is locking in the first place when in 4th gear, keep your foot on the pedal and maintain speed, with the other foot, LIGHTLY press on the brake, just enough to have the brake lights turn on. If the RPM's go up a few hundred, then back down when you release the brake then it's locked up. If the RPM's dont move at all,t hen it isnt locking up and you have a SERIOUS problem.

 

Thanks for Info. Doe'e not having the ECM hooked up, have anything to do with not locking up in 4th gear. Thanks again
Neal

 

YES! It does! BUT, not in the way that everyone likes to think. The only thing the ECM does is provide a 12v power to the tranny. Thats it, that simple. Nothing else involved!!! No special sensors, nothing, just a simple 12v wire.

You need to provide it a 12v source that breaks when you hit the brake pedal.

How long has it been like that dude? You've probably smoked your tranny.