Parts list for converting '78 Seville to carb?

[David Randall]

All,

I found a '76 Seville parts car that has been converted to carburettor. Exactly what do I strip off this car for a future conversion of my own? I've been told I may need the fuel tank, is this true?

List as I understand:

- Olds 350 intake manifold
- carb
- fuel pump
- EGR if wanted

Any more?

Thanks,
'78 Seville - pewter w/ red leather

[TommyO]

In 1978 My parents gifted me their 76 Seville  lemon (with throttle body fuel inection)  I remember it well!  It would sometimes drive for 500 miles w/o a glitch and then would stop dead!  AAA would tow it in, and call a day later and ask what the problem was...By then it was running fine.  Local Caddy dealer asked us not to bring it back as it was such a problem.  I gave the car to a friend and he took a manifold and carb off a Pontiac grand prix that he had and ran that beautiful car for almost 200 thousand trouble free miles.  I will get in touch with him and find out what he did in addition to keep it going~

Ironically, they purchased a new Seville diesel in 79, because my dad liked what he called the Rolls Royce style trunk look. which gave up the ghost at 42k miles!!

tommyO

[TJ Hopland]

75-79 Cadillacs with fuel injection (standard seville, option on other cars) were multiport.  The TBI (originally known as DEFI) came out in 80.  I think there were still a few multiports in 80, seems like the CA cars?  If someone could not tell the difference that would explain why they were not able to keep it running.  If this all happened in the 70's I guess you could give them some slack since FI was pretty rare (like carbs now). 

If you are a do it yourself sort of person something to consider would be converting to a more modern EFI system.  Changing it ECU is not a problem, there are a few choices out there.  I have been told that modern injectors are easily modified to fit.  Slightly more work is things like the TPS and IAC.  The TPS (throttle position sensor) on these cars is more of of a switch that can tell wide open, closed, or movement.   Modern systems use a constant variable signal.  I have read that there is a jeep one that is not too hard to modify to fit.  That leaves you with the IAC (idle air control) which I have read is a common problem with these engines and are really hard to find because they have not been made for a long time.   I have seen people modify them but it looks like a lot of work.  An easier solution is a solenoid that kicks open the throttle for high idle much like the anti dieseling or ac solenoids that many of the 70's carbs had on them.    If you want to know more about this option email me and I will get you some more info to research and make your own decision.

As for the carb option the intake and everything on it is needed.   The rest of the fuel system is up to you on how much work you want to go through.  If it was me I would consider keeping the electric fuel pump.  You will just need to get a adjustable fuel pressure regulator that will knock it down to what the carb wants. I dont remember if those had in tank pumps or if those were still external.  If they are external I dont see why you would have to change the tank going to a mechanical pump.  The EFI tanks would have included extra baffles to lessen the chances of the pickup getting uncovered when the level was low.   If its an in tank pump you have to remove it to draw fuel through it.   If its like other GM's the pickup assy is pretty much the same for efi and not its just the efi one has a pump hanging on it.  I have seen where people just remove the pump and insert a piece of hose in its place so a mechanical or external pump can be used.  If your distributor has the vacuum advance sticking out of it it will work with the carb.  The EFI trigger part was down in the stalk so it wont hurt to not have it hooked up.  In 78 there was an electronic timing option listed for the seville, not sure how common it was, I have never looked close at a 78 seville (most of these systems I worked on were in 76 eldo's).  The electronic ones would not have the vacuum advance can, just a harness going to some sort of a module / control box. If you are going for no computer stuff you might as well get rid of it and grab the dizzy out of the donor motor.  You may be better off swapping the dizzy anyway that way you can keep the EFI system complete and sell it all together to someone that wants the original stuff for an original car or maybe a guy that wants to put multiport efi on an olds motor.   

Dont forget to check what the emissions/ inspections laws are in your area or any area you may find yourself moving to in the near future.  Im fairly certain that in most if not all US states any modifications would not be considered legal.  Most states any swaps or mods have to have been a factory option for that model.  If the setup was for a later year of the same model the car then has to meet all the specs for that later model.  For many people this is a deal breaker, 'they' dont make it easy to own and enjoy a classic car.   Do your research before you start the project.

[Otto Skorzeny]

Dont forget to check what the emissions/ inspections laws are in your area or any area you may find yourself moving to in the near future.  Im fairly certain that in most if not all US states any modifications would not be considered legal.  Most states any swaps or mods have to have been a factory option for that model. 

I think you're mistaken.

Most states don't have emission requirements for 30 year old cars . Georgia only tests emissions on cars 25 years old and newer and that's only in certain metropolitan counties (generally surrounding Atlanta). If you have a 1930 Ford and want to put a brand new engine of any type in it, there are no emission requirements whatsoever. The car is registered as a 1930 Ford.

California is the main exception to the rest of the country.

[David Randall]

I dont remember if those had in tank pumps or if those were still external.  If they are external I dont see why you would have to change the tank going to a mechanical pump.  The EFI tanks would have included extra baffles to lessen the chances of the pickup getting uncovered when the level was low.   If its an in tank pump you have to remove it to draw fuel through it.   

The '77 - '79 Sevilles at leats have two fuel pumps; one in the tank and one on the chassis.

Thank you for the info.

[TJ Hopland]

I think the key word is 'test emissions'.   I suspect since the 60's when the Feds got into the auto emissions game they have put laws on the books and I doubt those have changed.  If your car is registered as a 69 and there were rules for a 69 they would still apply.  Are most states going to ever look or care?  Doubt it but just tossing it out there so someone does not go through a lot of work only to find out they cant get it registered and enjoy it.   I have talked to and read about a lot of  people that have been forced to sell nice (slightly modified) cars because of where they live. We had inspections in my area for a while and it was quite a hassle with lots of loopholes.  Luckily #1 priority was to collect the money, meeting some sort of standard was sort of a secondary concern that was hit and miss depending on the staff that was on duty the day you were there.

If anyone knows for sure feel free to post links to the actual laws but I suspect like most government stuff the info we are after is buried deep in pages and pages of stuff that even many people that work in those departments dont understand...  which is why there is so much bad info out there on the subject(s)....  and I admit I could be right in there passing bad info....

[David Randall]

Are most states going to ever look or care?  Doubt it but just tossing it out there so someone does not go through a lot of work only to find out they cant get it registered and enjoy it. 

I have read that California enforces that he car has the original equipment emissions or at least the stock carb. Is this correct?

David