Upgrading my EC1 model E to a newer model

Propane, Butane, LPG, GPL, C3H8, C4H10
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Islander
Posts: 4
Joined: Fri May 25, 2018 12:20 am

Upgrading my EC1 model E to a newer model

Post by Islander » Fri May 25, 2018 5:29 pm

Hey guys, first off I just want to thank everyone who's taken the time to share your knowledge on this forum. Since finding this site I've learned a ton about how these propane systems work!

I've got a 1986 Dodge B250 van with a factory propane setup. 318 engine with the CA225 carb and an Impco model E vaporizer.

The original vaporizer was damaged so I ordered a new one. The one that came with my van had the EC1 system installed, whereas the new one just has a little button on the top. It's the C-EB-2 model which I believe is the latest and greatest... supposedly better than the EB2?

I also ordered the AV1-12-2 air gas valve for my carb. So my understanding is that I just need to replace the vaporizer, change the air gas valve, and then plug off all of the extra vacuum lines that were used for the EC1. Is there anything I got wrong there, or will I need to do any other tuning to get everything running smoothly? I also got a tach and a vacuum gauge, so I think I should have everything I need to ensure proper operation.

Sorry if this has been talked about before. I've read several threads, I just want to make sure that there is nothing i'm missing here.

Edit: I just realized that what I ordered was a knockoff model E made by Century. Dealer seems reputable and they've been mentioned in this forum before, and from the images it looks nearly identical so I think i'll just stick with it.


Islander
Posts: 4
Joined: Fri May 25, 2018 12:20 am

Re: Upgrading my EC1 model E to a newer model

Post by Islander » Tue May 29, 2018 1:07 pm

So a little update on this project. I got everything removed and spent some time tracing all the lines. I found that a start assist had been installed, but the plastic screw on fitting that goes into the vaporizer snapped right off. The output was teed off into both the carb and the EC1 cover which seemed odd. I'm going to remove it and try running without it. I live on vancouver island, so we have a pretty warm climate. But if I have problems i'll just replace it with a new one.

Here is another thing I found which I thought was pretty interesting:

Image

This is a pneumatic tank switch system. Manifold vacuum goes to each of these little solenoids. Depending on which solenoid is energized, it will open one of two VFF30s attached to each tank, the outputs of which are teed into the vaporizer.

I do find it a little odd how they are reversed. One has input on the plastic takeoff, while the other has input on the metal one. I am assuming that the vacuum output is always going to be that single perpendicular takeoff on the side, although i'm not 100% sure since one of the vacuum lines did slip off when I wasn't paying attention. My best guess is that it's some kind of a fail system. If the solenoids lose power, then at least one tank will always be open by default. I guess i'll just have to listen to see if I can hear one of those things whistling when I get the van running!

Islander
Posts: 4
Joined: Fri May 25, 2018 12:20 am

Re: Upgrading my EC1 model E to a newer model

Post by Islander » Mon Jun 04, 2018 2:03 am

Welp, repairs were really coming along until today. Got everything taken apart and all the new components in place! I plugged off all the old vacuum lines that I wasn't going to need any more, and got everything pretty much mounted in place for a test run. It started on the first try!

Initially, the first thing I wanted to do was check all of the high pressure fuel lines for leaks. I put soapy water on all of them, and within a minute of starting the van I found one small leak. I took all of those fittings apart, cleaned them, put them back together, and went for round 2!

Check out this video to see what happened:


First, you hear an odd hissing sound. Then there is an awful growling noise. With the engine off, I left it to settle for a minute (in case there was a gas leak.) Upon returning I found the coolant spilling out of the overflow tank. It wasn't a consistent flow, either. It was these big gulps which you can see in the video. Eventually, all you can hear is fluid flowing into the engine through the main hose that comes off the water pump.

I'm a little stuck here so i'm going to do some thinking before I get back to it. My main concern is that propane is leaking into the coolant through the vaporizer somehow. I did tighten the LPG fitting pretty tight.. maybe I bused through a wall of the heat exchanger?

Of course, I think it's more likely that I just have a bunch of air in the lines from when I first broke off the coolant line on the old vaporizer. I did fill it up and prime the lines, but I never ran the engine so there is a lot of places the air could be trapped.

I just can't help but shake the feeling that I smelled gas when the radiator was overflowing. If I am leaking fuel, continuing to work on the van would be pretty dangerous so i'll have to diagnose the problem before I work on it again.

BigBlockMopar
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Re: Upgrading my EC1 model E to a newer model

Post by BigBlockMopar » Mon Jun 04, 2018 5:59 am

Sounds bad. Air in the lines is fairly normal and should normally end up in the radiator or remote canister, without barfing out too much coolant.
Take off the radiator cap and stick your nose in there. Should be easy enough to smell 'raw' LPG.
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Islander
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Re: Upgrading my EC1 model E to a newer model

Post by Islander » Fri Jun 15, 2018 2:26 am

You were right. It wasn't just air, and the problem should have been more obvious. Turns out that the issue was caused by the vaporizer. I must have over-tightened the LPG inlet fitting and cracked the body, which allowed gas into the coolant system. Suppose I was just being wishful that it was something simple! :lol:

Oddly enough, the replacement vaporizer I bought was designed a little differently. The first one had the gas inlet tapped through a welded seam. Whereas this new one has a square cutout around the port, which looks to be welded in. I'm thinking that they either changed the design, or that this is a common problem and the square cutout was a repair.

The rest of the job was a breeze. Slapped the parts in, tweaked the idle mixture, and the engine runs strong now. It could use a bit more tuning, but this will do for now while I flush the coolant and clear up a few electrical gremlins.

In spite of my setbacks, removing the EC1 was a pretty simple process. Just plug off or remove the vacuum lines and replace the gas valve in the mixer. There were also two more lines going from the EC1 cover to a start assist valve, and then from the valve to the throttle body. Had I decided to keep this, it looks like it would just connect directly to the body of the mixer. For anyone else doing the same swap, i'd highly recommend turning the idle mixture screw roughly 50% of the way in before you try to start it for the first time. Otherwise the setting will be way too lean with a regular model E mixer and you'll have trouble starting.

As far as this project is concerned, my next step is going to be to properly adjust the idle mixture. Might pick up an AFR meter. Then i'll check my timing, and upgrade the ignition. I'll update this thread if anything interesting happens.

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