ok..so I'm still having odd top speed issues.. and so after pulling the EFI fuse yesterday it still has the same symptoms...

ECT : off
O/D : on
89 octain

even on flat roads I get up to 69-75 but I can't hold it.. the overdrive kicks in and lowers my RPMs to ~2800 and then I loose speed... I can gun it and the tranny kicks down and my RPMs go to about 4000, I gain speed again... but once I back off the gas a bit, the RPMs go back down and I loose speed. it seems like the speed it likes to be at without downshifting is ~64.. I don't have the egg smell so I don't think the cat is bad...

anybody have any ideas? please?

 

Have the rear brakes been changed or adjusted recently?

 

nope, why?

 

Shouldn't the ECT be "on" and the overdrive "off"?

 

Do you have a mechanical fan? If so check your fan clutch, could be frozen.

 

the shop guys just repacked the fan clutch like a 2 months ago so I hope it's not that..

 

Do a tune-up:

Plugs
Wires
Rotor
Cap
Fuel Filter
Air Filter
Redline S1 Fuel system cleaner
Check your timing - if it's too retarded (haha) you will definitely be losing power.

Do that stuff first then get back to us.

:bounce2:

 

Sounds like the problem is that once you get to that speed your throttle position is at the 'kick-down' point - it thinks you want to go faster (you do!) and you don't have the "oomph" to do it without a lower gear. Same way a Vette with a six speed can attain it's top speed only in 5th, not in 6th - need the rpms for more power. On older vehicles I would think adjusting the kickdown rod is in order... Is your Throttle Position Sensor adjustable? Or do you just need a tune up as AgRunner suggests?