I have a 1984 camaro coupe. Just a standard car. it has however a computer controlled quadrajet, O2 sensor and what not. Originally it was a 5.0 with a 700r4 auto trans. Now it's a 350 bored .40 over with an rv cam new pistons etc... ever since i put this motor in, my temperature light and my service engine soon light were both on. I put a newer type of sender with the two pig tails on it and that turned the light off and it stays off now. i unhooked the battery for 30+ seconds. It only called for 30 in book but i left her unhooked for a couple of minutes anyways. i started it back up ran down the road a couple miles and the service engine light was back on. i get around 10 miles to the gallon. it even smells like it's running rich. anyone any ideas?

 

You sure everything with the engine swap was hooked back up correctly? You may have missed something and I would go back through everything with a comb to see if maybe something is off. Maybe the SES light is faulty? What kind of gas mileage did you get before the swap too? Getting 10mpg wouldn't be surprising if your gas mileage was about the same before.

I'm just making some educated guesses as to what your issue maybe.

How is the car driving overall? Is it stalling, making weird sounds, weird smells besides the possible running rich smell? There's a ton of possibilities.

 

Oh, and welcome to TGO. I hope your stay here is pleasant.

 

well i originally got 14 but before the motor swap i noticed the O2 sensor was broke off so i figured that was the reason why it only got fourteen. no funny smells or funny noises car overall when you put premium in it runs excellent. no unnecessary drag good pull idk but i do know that the temp light does not come on when i turn my key on. not until the motor is started do i see it blink

 

This seems to come up a lot,
When swapping from a 305-350 you will need a 350 prom and a 350 EST.
GMPP's 350 swap for F-bodies came with a these items. (also the dual snorkel air cleaner!)
From an old GM Performance Parts catalog the PROM part number is 24502457 for the 82-84 LG4
EST P/N 16128261
Now those GM part numbers are from a 1999 parts catalog but I would think a AC Delco dealer could say what numbers they changed to if any.

Oh and I forgot, code 15 is for the Coolant Temp Sensor and that is located in the intake manifold, not the one in the head. That one is for the gauge or light only.
The CTS in the manifold comunicate with the computer only. If it has never been changed it will have a single yellow wire. The new sensors for it will be a two wire kind and one wire need to be grounded.

 

Ok when it comes to computers on vehicles i'm not exactly the "go to guy" lol so the CTS is? And does What exactly? I think i have an idea but just to make sure. and what is a 350 prom and 350 est?
And i do have that coolant temperature sensor. The newer one and it is in the thermostat housing. that was where it was when i bought the car so i figured i'd best put it back. but i did buy the newer sensor and pigtail just recently but it didn't help any.

 

CTS= Coolant Temp Sensor
It send the engines temp signal to the computer.
You stated you had a service engine light and a temp light and when you replaced the sender the light turned off. I assumed you replaced the temp sender located in the cylinder head for the temp light and that light went off.
Many people confuse the sensor and sender.

The CTS is located in the intake manifold. If its bad it will trigger a service engine light. The temp light sender does not.

The PROM is the chip in the computer. You went from a 305 to a 350 you will need on calibrated for a 350.

EST= Electronic Spark Timing
This too needs to be replaced with one made for a 350. On a bracket on your firewall you will see a square, somewhat flat module. That should be the EST.
You can look up the parts and see pictures on the web. Try autozone.com for pics

 

I recently talked to a man that worked at GM dealership for 30 years. Unfortunately he is now a FORD fan lol, but still knows his GM's like the back of his hand. i told him the problem i was having and he said to unscrew the CTS on the thermostat housing while the car is running until you start to see antifreeze run out. Said sometimes they develop an air pocket there and the sensor can't read anything causing the beloved CODE 15. Then to leave the battery unhooked for 1 hour. So i'm going to try that and i will post the results in a bit.