I swapped in a Vortec 355 into my trans am....well i have finally floored it and it seems like the timing is NOT advancing when the RPM's get over 3000-3500....it starts to misfire and run like crap...well i have the stock CC Q-jet and distributor in there but i dont have the o2 sensor,EGR,map, or basically anything else hooked up....i just have my temp sensors and such that were connected to the block

one of my questions is that i was curious as to which of the sensors i would have to hook back up in order for my computer controlled distributor to advance the timing as the RPM's increase.....or would i be able to swap in a non-CC distributor and what kind of problems would i run into with that? ....right now it seems like my car is running just a little rich...but if i do plan on sticking with the CC Q-jet then i DO plan on getting an O2 sensor bung put into the headers....but if not then i plan on just going for a 650 Holley with the non CC distributor....but then the other question arises...... what sensors control the lock up of my Torque converter and by having all of these things unplugged mess up the computer and make it so it does not lock up the torque converter anymore? right now it runs about 2200-2300 rpms at 60 and it has 3.73's and .70 4th gear....so i think its locking up because those rpm's are basically all it has ran even when it had the old motor in there......


any help would be greatly appreciated because i would really like to drive this car a lot more now that i have a new motor in it!!

thanks!

 

In order for the computer to know what to do, it needs the input that it was designed to have. That means O2 sensor, coolant temperature sensor, manifold absolute pressure sensor, barometric pressure sensor, throttle position sensor, and the distributor connector connected. Without the proper sensor inputs, it will not go to closed loop control and will operate in "limp home" mode - no power mode. It will also go to a default rich mode.

The EGR is an "output", and unless the computer senses the presence of the EGR solenoid coil load when it commands it to operate, it will set a trouble code.

Most likely you are getting to 4th gear (overdrive), but the torque converter is not locking up. The TCC will only lower RPMs under load (such as up-hill). If you're cruising and give it a little more gas and the tach jump up, the TCC is not locking.

Either set it up as it was intended to operate, or go to an old-school open loop mechanical system.

 

thanks for all the input on the sensors....im gonna see what else i can hook up and see if it will help...if not then i will just do old school option.....

with the torque converter though.....how much RPM increase do you mean...cuz if i give it just a little bit more gas, the RPM's do not go up too much...just a little bit....in either case the worst thing i would have to do is just get the little lockup kit from jegs or summitracing....so i may end up doing that anyway....