Expert: Paul Wilczynski - 5/30/2009

Question
QUESTION: I have a 1969 Nova.  The accelerator takes off without me.  If I apply firm pressure to the accelerator when coming out of a turn the engine immediately revs and I lose control of the acceleration.  I can only stop the car by turning it off.  HELP!!!! Any ideas?

ANSWER: Sure! You need to check the entire throttle linkage including the accelerator pedal pivot. Also make sure the throttle return spring is in place--the carb has a weak spring, but you need a spring on the linkage, too. If it's a cable from the pedal to the carb bracket, the cable should slide freely.

Automatics will have a cable or rod-type kickdown linkage, this needs to move freely, too, so check that it's not causing the carb to stick open.

Fix this immediately--it's a major safety problem. Don't drive until it's been corrected!

--Paul

---------- FOLLOW-UP ----------

QUESTION: Thanks for your prompt response.  Here is what we have done so far: the accelerator linkage is not a cable type - so we have lubricated and checked all joints for any sign of binding.  It appears clear.  The accelerator spring is new and in good shape, it is not dragging.  We have temporarily disconnected the kickback linkage on the automatic but the problem continued.  The problem is when we accelerate, as if you were merging onto a highway, the accelerator feels like it is being sucked out from under your foot.  The car rapidly accelerates up to 4000 rpms before I can turn the key off.  Seconds later when I turn the key back on it resumes normal rpms.  It does not happen if you accelerate very slowly as if you were driving in a school zone.  The engine is a 350 bored .060" over, large hydraulic lunati cam, 750 cfm Holley carb & Holley high pressure electric fuel pump.  This is a followup question to try and explain what we have tried and what is failing.  We appreciate your help as we try to restore our toy to its normal safe operating status.  Thanks again for your help.  We are really stumped and very anxious about repairing our Nova.

Answer
OK, have you checked choke operation, carb floats and the accelerator pump? Sounds like gas in pouring into your motor, and my next guess is that something in your carb's metering system is sticking open instead of properly vaporizing the smaller amounts of gas.

Tough to diagnose at a distance, but I'm giving you my best shot!

--Paul