alright this car is working perfectly except for this issue...ive tried everything i can think of so if anyone has an idea please help. its a TBI 92 rs camaro, was a 305 now its a 350. its completely stock 350 except for the headers and exhaust. for some reason the car when driving and idoling will have dipps in the RPM's and also in the voltage and eventually the car will stall out. i supected a loose ground somewhere but cant seem to find one. im getting a number of codes from the computer but if they were all really problems this car wouldnt be running. i have list of the codes but they arent with me ill post them and what they stand for shortly...im at the end of my rope here. please help. thanks in advance!

 

Hey Pandemic, I just did a 305 to 350 swap myself... I kept my TBI, I changed the knock sensor, computer, prom chip, and injectors, and I am STILL having a problem with my RPM gauge bouncing! It like drops and jumps alot when I get on it hard, and sometimes, right after startup, when it's idling, it jumps pretty bad and othertimes not as bad... But I do notice it really does it when I floor it... Any ideas??? Someone please help us both! We seem to be having the same problems! Thanks

 

Let's be clear and see if I have this right:
Pandemic: having problems with actual engine rpm going up and down (surging)?
Brodband: having problems with the indicated rpm on the tach going up and down different than the actual engine rpm?
Pandemic, are you using the original 305 ECM?
Brodband, check the connection where the tach wire connects to the coil for loose connection.

 

ok update...did a complete tune up. yes i still have the 305 ecm but i just came across somthing interesting. the plug that goes into my voltage regulator is kind of loose. its in all the way but if i so much as touch it while the engine is running it stops charging! im gonna change the plug and see if it helps. but the stock ecm is in the car...should i try using a different chip?