about 2 weeks ago i posted what timing light should buy. got several replies and i thank you. i ended up purchasing a innova 3551.. so i taped the ignation switch to get the timing mark so i could see it. took white out and marked the line, turned the car on could not see white line so loosened the hold down on the dist. turned the dist clockwise walla it appeared got the mark to 10 to 12 degrees had my wife shut car off and tightened down the dist hold down bolt. wow no more pumping the gas pedal. let car set over night got up this am got in the vette taped the gas pedal to set the choke than taped the pedal again slightly turned on the key and wow it fired up. so i go for my morning coffee now in the past when i got back into the vette and turned the kay i had to pump the gas pedal and it sounded like the battery was dead it tried to start . this morning got back into the vette never touched anything turned the key on and it fired up. I know there have been a lot of postings on vette owners having to pump there gas pedal in order to get there car started maybe this is there problem. in closing iam 82 years old farily handie with a wrench. but this forum has saved me several thousand dollars in repair costs if i were to take it to a mechanic some where. every morning i get up go for coffee and after reading the obits to see if i had died i than go to corvette forum. so once again thanks to all of the great people who post here ED

 

Do you still have the original computer CCC system? If so try setting the timing to 6 degrees factor and start there. I’ve been there and it’s best to start at the original basic settings and then customize. I rebuilt my engine and carb with, bumped up the cam a little with new, increased compression from 8:1 to 9:5. I played with the timing up to 14 degrees, but mine likes to be between 8 to 10 max. Also check for vacuum leaks, they wreak havoc on the 81. As far as pressing down the gas, these cars always rely on pumping the gas when cold first thing in the morning at least 3 pumps. After warmed up though I use none or it will have too much gas delivered and cause a possible flood condition.

 

If you have the original computer system you first have to disconnect the electronic spark control connection at the distributor before setting the timing.

 

I do not have the computer, every thing was removed prior to me purchasing this mess. they had the wrong carb in it lars fixed that for me put a new HEI ignition in it. new spark plug wires the whole 9 yards, havent started it for 2 days now i bet if i went to the garage now tap the pedal to set the choke, a lite touch to the gas and it will fire right off, now let me tell you it took me a year to figure this out, with the elect. choke it does take aprox 2 min for it to warm up properly.

 

Ed -
Glad to hear that '78 carb with the electric choke conversion is working out well for you -sounds like it's doing exactly what it should do - good job nailing down the timing!

Lars

 

thanks lars

 

Hopefully you disconnected the distributor vacuum advance before setting the initial timing?

 

there is no vaccum on a HEI system.

 

Ed -
If you have a non-computer-controlled HEI, it has vacuum advance, and you need to hook it up and use it. If someone has installed a "racing" distributor without vacuum advance, you need to ditch it and get a stock HEI distributor with vacuum advance.

Lars

 

The other troubling possibility is he still has the computer controlled HEI distributor that did not have a vacuum advance even though he states the computer control is gone.

 

That would not be good, but he did indicate he put a "new HEI system" in it... Hopefully he installed a non-ECM HEI distributor, which does, in fact, have vacuum advance, and it needs to be hooked up.

 

lars this does not have a vaccum advance on it

 

so lets talk vacuum or no vacuum advance. last week after setting the timing between 10 and 12 degrees i could not believe how well the car run the 10 to 12 degrees was at about 700 RPM when i drop it into gear the RPMs drop to 600. back in parl rev engine up to between 2500 and 3000 RPMz the timing mark moves guessing on this 16 to 18 degrees BTDC as my timing guage only goes to 12 degrees . let car set over night and in the morning the engine was cold lightly taped gas pedal to set choke pushes on gas pedal to give it a little gas turned on key fired up to around 1200 RPMs let it warm up taped on gas pedal droped down to 700 to 800 RPMs perfect in my eyes told the wife lets take a ride went to a country road near my house going down it behind 2 cars at 50 MPH than came a long stretch of road i hit the gas pedal that car did not even get a hic up shot up to 85 MPH, I backed off pushed on the pedal to speed up and let it slow down several times than found a hill no cars behind me or in front told the wife hold on and floored it it was over 75 in seconds. ( and iam 82 yrs old) so now tell me why i need a vacuum advance, noow lars if your reading this i have the upmost respect for your comments we have talked about a year ago several times

 

which hei? this one? https://www.ebay.com/itm/For-Chevy-V...Cclp%3A2334524 or this one? https://www.ebay.com/itm/For-Chevy-g...EAAOSwNSRgAqok if the first and no vacuum can it may have had this vac eliminator added. https://www.ebay.com/itm/HEI-Distrib...AAAOSw9vlacJa6 if the second one, you need either a new distributor or an efi setup to go with that distributor. it is designed to be run by an ecm. although it has about 10 degrees of limp home "centrifugal" advance built in. there is also an aftermarket small "HEI" distributor but i believe they are all vacuum. and edward you need vacuum advance for gas mileage when you aren't flooring it. most of a car's life is spent at 10 to 15 percent throttle and 45 degrees or so burns that light charge more effeciently.

 

Ed -
First, if you are running a distributor with no vacuum advance in your near-stock, street driven Vette, you are giving up a lot of performance, fuel mileage, and throttle response. Get rid of it and get a correct distributor with vacuum advance.

Secondly, you are not setting up your timing correctly, and your distributor is not working right: If you are setting your timing to 12 initial, and it goes to 16 or 18 when you rev it to 2500, your distributor does not have centrifugal advance in it, which indicates that you have an ECM-controlled 1981 distributor (which does not have vacuum advance or centrifugal advance) that is not hooked up to the ECM. This is seriously messed up, and needs to be fixed. Your timing should go to 36 degrees when you rev it to 2500-3000 rpm, so you are running grossly retarded.

If you are not going to run the ECM system, you need to replace your distributor with a correct, non-ECM HEI with vacuum advance. You cannot use that thing you're running - it's really messed up.

Lars

 

o.k. you guys i will take your advice and order from summit one with vacuum advance

 

Don't go cheap Chinese on it... consider ordering one from D.U.I.
Lars