1962 Fuel Injection Misfire/Surge

[Rob Howell]

Hello everyone,

I am having an issue with my 1962 fuelie, which I purchased a few months ago. I did not rebuild the engine so I am unaware of the exact configuration, but it appears stock. It has the correct 360 FI unit, the correct 1111010 distributor, with 36* total timing that comes all in at around 2800 rpm. The block is a numbers matching 870, and the heads are correct as well. I am unsure of the compression and cam but think they are probably factory spec. The vavle lash is set to factory. The engine idles around 1000. If I go lower, the car will start to float on and off the economy stop.

The problem I am experiencing is that the car misses between 2000 and 3000 during light accelleration (it feels like the car is starving for fuel). I assume the car is on the economy stop during this time but have no way of knowing for sure. If I accelerate hard I do not notice it as much. I do not hear any detonation and run 93 with Octane Supreme 130 (.5 qt per 10 gallons 93).

I suspect the car is running lean. I replaced the plugs when I bought the car and after a few hundred miles the porcelin is pretty close to white. There is no fouling at all and the ground strap and electrode are pretty clean. The plugs I took out originally looked pretty much the same way, and all 8 plugs were consistent. I am just about positive this is fuel delivery related.

Can an FI guru chime in please? This is my first fuelie.

Thanks.
Rob

[Kevin M.]

Re: 1962 Fuel Injection Misfire/Surge

Rob,

Check out this site might have the answer to your questions.

http://www.jerrybramlett.net

Kevin

[Kevin M.]

Re: 1962 Fuel Injection Misfire/Surge

Rob,

Check out this site might have the answer to your questions.

http://www.jerrybramlett.net

Kevin

[Rob Howell]

Re: 1962 Fuel Injection Misfire/Surge

Thank you Kevin, that is a very interesting site.

A couple of details I negelected to mention--adjusting the idle mixture screw has no effect immediate effect. I currently have it adjusted to about 2 turns out, but turning it either way does not have an effect.

After driving the car, I always smell strongly of gasoline, which to my knowledge can indicate a very lean condition. The previous owner replaced the gas tank. I'm not sure if he replaced the filler neck and drain, but immediately after driving, there is never any wetness in the filler area so I do not think it is fuel sloshing out of the tank.

[Rob Howell]

Re: 1962 Fuel Injection Misfire/Surge

Thank you Kevin, that is a very interesting site.

A couple of details I negelected to mention--adjusting the idle mixture screw has no effect immediate effect. I currently have it adjusted to about 2 turns out, but turning it either way does not have an effect.

After driving the car, I always smell strongly of gasoline, which to my knowledge can indicate a very lean condition. The previous owner replaced the gas tank. I'm not sure if he replaced the filler neck and drain, but immediately after driving, there is never any wetness in the filler area so I do not think it is fuel sloshing out of the tank.

[John D.]

Re: 1962 Fuel Injection Misfire/Surge

Rob, Sounds like a simple fix to me if you are lucky. Sounds like you may have blown a cranking signal valve. I assume you have the shop manual for your car. If so it's called Corvette Servicing Guide of the St-12 manual or both. Anyhow to trouble shoot the problem yourself go to the FI section and read the last couple of pages. Check those individual components and you have the answer. Meanwhile check out the CSV to see if it's blown. Many posts on the DB here on that subject for sure. Don't waste your money though on an expensive NOS one on the auctions. Get a good original one that has been rebuilt. Stay away from the new repros also as they are questionable at best. John

[John D.]

Re: 1962 Fuel Injection Misfire/Surge

Rob, Sounds like a simple fix to me if you are lucky. Sounds like you may have blown a cranking signal valve. I assume you have the shop manual for your car. If so it's called Corvette Servicing Guide of the St-12 manual or both. Anyhow to trouble shoot the problem yourself go to the FI section and read the last couple of pages. Check those individual components and you have the answer. Meanwhile check out the CSV to see if it's blown. Many posts on the DB here on that subject for sure. Don't waste your money though on an expensive NOS one on the auctions. Get a good original one that has been rebuilt. Stay away from the new repros also as they are questionable at best. John