Restarting My '70 Nova Project

[BravoXray]

In your shoes I’d change out the fuel line not because of pulsation but to eliminate any problem with blockage. I’d even take down the pump for inspection.
Secondly, you’ve built yourself a fine car and sunk a lot of time and money in it.
I think both the car and you deserve only the best so do it up with a new fuel delivery system if you need to.

There isn't and blockage, I pulled the line at the EFI unit a while back, turned the ignition on and it had a lot of flow, filled a coffee can in several seconds. The pump is rated at around 75 gallons per hour. I never had a problem with fuel pressure under a load, it bounced around mostly at an idle.
I got the hard lines pulled out this afternoon and put one end on the new line. Needed a AN-6 union to connect the short line going to the EFI unit to the line going to the tank, so I ran in to the local speed shop and picked up a couple of them. I'm going to measure the hard lines and connector hoses to get the length for the new hose. I don't want to thread it into place secure it with the loom clamps and then have to pull it back out to cut it to length and put the other fitting on the end.

 

[BravoXray]

OP: how long has this project been going on?

I tore the car down for restoration in 2012. Took it to the body man in late 2013, he had it until early 2017, sat in the back of my shop until 2021 when I started working on it again. Got it painted in January of 2023 and finally had it on the road in spring of 2024. I only have a couple of things left to do on it until I could call it finished. But it will never be done, these things never are unless you sell it.

 

[arrow]

A project like this is never finished.

What I discovered with my vehicles was to find a culmination with a result.
For me, a project was done when I reached the result I formulated at the beginning.
At first, it was the shear beautification of the vehicle and unless I sold the thing, projects like that never ended otherwise.
I then concocted to the performance end and set my goals that way.
I applied track times as the end note but the trick to that is to adhere to the initial criteria which in itself can be an addiction if one is not careful.
I set 12.2 thru the quarter for my Dakota. It is at 12.34 at its 4300 lb weight so I have just a bit more to do with it suspension wise. When it reaches 12.2, I am done with this 9 yr build.

 

[big bubba]

I tore the car down for restoration in 2012. Took it to the body man in late 2013, he had it until early 2017, sat in the back of my shop until 2021 when I started working on it again. Got it painted in January of 2023 and finally had it on the road in spring of 2024. I only have a couple of things left to do on it until I could call it finished. But it will never be done, these things never are unless you sell it.

View attachment 4049626View attachment 4049627

outstanding job requiring patience & attn to detail. a centerpiece when finished. doubt you'd sell, but what is projected market value?
maybe the Pebble Beach car show

 

[Alan46]

What I discovered with my vehicles was to find a culmination with a result.
For me, a project was done when I reached the result I formulated at the beginning.
At first, it was the shear beautification of the vehicle and unless I sold the thing, projects like that never ended otherwise.
I then concocted to the performance end and set my goals that way.
I applied track times as the end note but the trick to that is to adhere to the initial criteria which in itself can be an addiction if one is not careful.
I set 12.2 thru the quarter for my Dakota. It is at 12.34 at its 4300 lb weight so I have just a bit more to do with it suspension wise. When it reaches 12.2, I am done with this 9 yr build.

With my experience in drag racing (30 years) at 3,000 lbs that would be almost a 10 second et.

 

[BravoXray]

outstanding job requiring patience & attn to detail. a centerpiece when finished. doubt you'd sell, but what is projected market value?
maybe the Pebble Beach car show

Thanks for the compliment, it's been a great project for me since I retired.
I have no idea on what a market value would be for it, these types of cars are valued at what someone is willing to pay for it, and thus varies widely.
I doubt I'll sell it, as it is willed to my son, unless he decides he doesn't want it.
Although I put the 434 SBC and a Tremec TKX transmission in it, I have the numbers matching 350 and Muncie 4 speed overhauled, preserved and stored. I also have a LOT of original parts that came off the car but were replaced with new parts.

 

[civilian]

Sounds like you might be able to build another one from the left over parts. I never was a car nut, but always appreciated the work done on them. And yours is great. I also had a 73 Olds Omega as my first car. Bright factory yellow hatch back. Jon

 

[MossRoad]

I knew a guy that had a Ventura with a custom license plate...

NONOVA

 

[arrow]

With my experience in drag racing (30 years) at 3,000 lbs that would be almost a 10 second et.

That’s the adage: 100 lbs equals a tenth.
Years ago Hot Rod magazine stripped down a 500 cu in Cadillac Deville to just the chassis and went 12’s with it.

 

[MossRoad]

My little Yamaha RD400 with a 25 cubic inch engine and my little 135# body would pull 11.92 pretty consistently. It only weighed about 450# with me on it.

I recall some car magazine article back in the 80s that focused on weight and wind, where they took a stock engine out of a car of that year and put it in a dragster frame and it ran pretty close to 10s.

 

[arrow]

My little Yamaha RD400 with a 25 cubic inch engine and my little 135# body would pull 11.92 pretty consistently. It only weighed about 450# with me on it.

I recall some car magazine article back in the 80s that focused on weight and wind, where they took a stock engine out of a car of that year and put it in a dragster frame and it ran pretty close to 10s.

The fastest car I owned was a 68 Cobra jet Mustang that ran in SS/E It went 11.28. That car with me in it weighed 3400 lbs and had to be well north of 450 hp.
What would be so comical to me was for your RD400 to pull up to my Mustang and pretty much stick with it through the quarter where I would be playing catch up from the hole.
Now just to put this all in tractor perspective. A tractor with 14 hp weighing 4000 lbs, would outwork my Mustang.

 

[goeduck]

The fastest car I owned was a 68 Cobra jet Mustang that ran in SS/E It went 11.28. That car with me in it weighed 3400 lbs and had to be well north of 450 hp.
What would be so comical to me was for your RD400 to pull up to my Mustang and pretty much stick with it through the quarter where I would be playing catch up from the hole.
Now just to put this all in tractor perspective. A tractor with 14 hp weighing 4000 lbs, would outwork my Mustang.

Reminds me of when I worked road construction. One day the road-grader operator and a flagger got into an argument. The flagger had a ~400 HP corvette and said he could out-pull the road-grader which was about 40 Hp. So one Friday night they hitched up a chain in the equipment yard and went at it. I left after about a half hour of the grader pulling that corvette backwards over the all over the yard. I don't know how long they went at it, but the flagger probably left with an appreciation of weight, gearing and traction over HP.

 

[BravoXray]

I got the hard fuel lines out of the car and the braided hose in on Thursday afternoon. I reset the EFI to factory settings and went through the setup process. Took it for a drive and it's no better than before so that was wasted time and hose.
I spent over an hour on the phone with MSD tech support, including about 45 minutes on Friday with the "MSD EFI guru". Seems like he is stumped too, the only thing he recommended was to change the IAC, the idle air control, which was acting strange sometimes. So I ordered one from NAPA, picked it up yesterday, and installed it this afternoon. It didn't make any difference at all as far as I can tell, so I'm going to call him back on Monday. If you rev it up over 2,000 RPM or more and then let it back to idle, it will almost and sometimes die for a few seconds before it recovers and goes back to idle speed. While at a steady speed with the engine turning 1,800 to 2,000 RPM, sometimes it surges like you are giving it more then less throttle. It has also started backfiring, mostly when shifting from 1st to 2nd and sometimes on the 2nd to 3rd shift. It never did that before, and is a sign of a lean mixture, or possible an exhaust leak. When I had it up in the air, after I got the fuel line installed, I started it up and checked the entire exhaust system for a leak and didn't find one.
If I can't get this sorted out, I'm just going to pull it off and get either a FiTech or Holley unit and put that on. I'm tired of messing around with this unit and want it running right so I can drive it without fighting it all the time.
I guess if I ran a return line to the tank, I could install a pressure regulator and slap on one of the Holley cabs I have setting on the shelf, it couldn't possibly be any worse.

 

[MossRoad]

Leaves are starting to change. Another year passes. But as you know, a car like this is never finished, so something to occupy your time and skills. Keeps your brain sharp, too.

 

[dodge man]

I’m not any kind of an expert on aftermarket Efi systems but it seems you have a limited ability to play with the fuel and ignition curves. I watched the guy tune my Challenger on an dyno and there are three settings for rpm bands for both ignition and fuel curves. He put a wide band 02 sensor in the tail pipe and the fuel curve is amazingly flat, nearly perfect. I think a newer system will let you fix your problem but then I’m spending your money.

 

[George2615]

Have you pulled the distributor lately? A friend of mine had similar problems of bogging and backfiring. I also thought it was too lean. Upon further checking I found he installed the distributor off one tooth. Moving the distributor one tooth eliminated all the problems.

 

[Alan46]

I got the hard fuel lines out of the car and the braided hose in on Thursday afternoon. I reset the EFI to factory settings and went through the setup process. Took it for a drive and it's no better than before so that was wasted time and hose.
I spent over an hour on the phone with MSD tech support, including about 45 minutes on Friday with the "MSD EFI guru". Seems like he is stumped too, the only thing he recommended was to change the IAC, the idle air control, which was acting strange sometimes. So I ordered one from NAPA, picked it up yesterday, and installed it this afternoon. It didn't make any difference at all as far as I can tell, so I'm going to call him back on Monday. If you rev it up over 2,000 RPM or more and then let it back to idle, it will almost and sometimes die for a few seconds before it recovers and goes back to idle speed. While at a steady speed with the engine turning 1,800 to 2,000 RPM, sometimes it surges like you are giving it more then less throttle. It has also started backfiring, mostly when shifting from 1st to 2nd and sometimes on the 2nd to 3rd shift. It never did that before, and is a sign of a lean mixture, or possible an exhaust leak. When I had it up in the air, after I got the fuel line installed, I started it up and checked the entire exhaust system for a leak and didn't find one.
If I can't get this sorted out, I'm just going to pull it off and get either a FiTech or Holley unit and put that on. I'm tired of messing around with this unit and want it running right so I can drive it without fighting it all the time.
I guess if I ran a return line to the tank, I could install a pressure regulator and slap on one of the Holley cabs I have setting on the shelf, it couldn't possibly be any worse.

I like your idea of swapping out to a Carburetor, that will tell you if it’s the EFI or not!!! Best of luck bro.

 

[BravoXray]

Have you pulled the distributor lately? A friend of mine had similar problems of bogging and backfiring. I also thought it was too lean. Upon further checking I found he installed the distributor off one tooth. Moving the distributor one tooth eliminated all the problems.

I set the distributor just as I have for the last 50 years, with the pointer on the rotor pointing at #1 cylinder, with #1 at TDC on the compression stroke.
I have checked the timing a couple of times lately wondering if that was the or part of the problem. It's right at 12°BTDC where I set it.
I spent another half hour this afternoon with the tech support guy changing every possible parameter that might contribute to the problem, all to no avail. After I got off the phone, I played around with it some more, and by running the idle up to ~1000 RPM the problem with it nearly dying, then going down to 3-400RPM if you rev it up and let it come back to idle, helped, but that's just a bandaid, not a fix. Somehow the system isn't turning the fuel back on until the RPM drops too low. It doesn't try to recover soon enough. If I can just get it driveable for a couple of months, this winter I'll convert it to another brand of EFI.

 

[BravoXray]

I’m not any kind of an expert on aftermarket Efi systems but it seems you have a limited ability to play with the fuel and ignition curves. I watched the guy tune my Challenger on an dyno and there are three settings for rpm bands for both ignition and fuel curves. He put a wide band 02 sensor in the tail pipe and the fuel curve is amazingly flat, nearly perfect. I think a newer system will let you fix your problem but then I’m spending your money.

Yes, the newer EFI systems give you a lot more ways to tweak the system, unfortunately, mine is an early system that doesn't have that capability.
That said, I don't think that type of tuning would solve my problem. As I said previously, for some reason the unit isn't bringing the fuel delivery back to idle volume until the RPM has fallen well below the desired idle RPM. I don't have an aluminum flywheel, so the RPMs don't fall off all that quickly, certainly no differently that it did previously.

Color me frustrated.

 

[arrow]

Yes, the newer EFI systems give you a lot more ways to tweak the system, unfortunately, mine is an early system that doesn't have that capability.
That said, I don't think that type of tuning would solve my problem. As I said previously, for some reason the unit isn't bringing the fuel delivery back to idle volume until the RPM has fallen well below the desired idle RPM. I don't have an aluminum flywheel, so the RPMs don't fall off all that quickly, certainly no differently that it did

I got the hard fuel lines out of the car and the braided hose in on Thursday afternoon. I reset the EFI to factory settings and went through the setup process. Took it for a drive and it's no better than before so that was wasted time and hose.
I spent over an hour on the phone with MSD tech support, including about 45 minutes on Friday with the "MSD EFI guru". Seems like he is stumped too, the only thing he recommended was to change the IAC, the idle air control, which was acting strange sometimes. So I ordered one from NAPA, picked it up yesterday, and installed it this afternoon. It didn't make any difference at all as far as I can tell, so I'm going to call him back on Monday. If you rev it up over 2,000 RPM or more and then let it back to idle, it will almost and sometimes die for a few seconds before it recovers and goes back to idle speed. While at a steady speed with the engine turning 1,800 to 2,000 RPM, sometimes it surges like you are giving it more then less throttle. It has also started backfiring, mostly when shifting from 1st to 2nd and sometimes on the 2nd to 3rd shift. It never did that before, and is a sign of a lean mixture, or possible an exhaust leak. When I had it up in the air, after I got the fuel line installed, I started it up and checked the entire exhaust system for a leak and didn't find one.
If I can't get this sorted out, I'm just going to pull it off and get either a FiTech or Holley unit and put that on. I'm tired of messing around with this unit and want it running right so I can drive it without fighting it all the time.
I guess if I ran a return line to the tank, I could install a pressure regulator and slap on one of the Holley cabs I have setting on the shelf, it couldn't possibly be any worse.

As long as the Holley is at least 750 cfm you can certainly go that route. Too bad for not having a mechanical pump or else you could have eliminated the return.