2023 State of CIS

[cmovic]

I'm curious what others think about the current and future state of CIS induction.

I've been driving my '78 SC with no troubles for almost 30 years (eek) until this summer. I was more than a little shocked to find out the Aux Air Valve that failed was a $1300 part ($1100 on Pelican). Browsing the catalog I see a lot of darned expensive and NLA parts, making me wonder if I should count on CIS going forward or start thinking about alternatives. My particular application is a track car so I don't have have smog/inspection concerns.

Thanks for any input.
-Vic

[fanaudical]

I was asking the same question 12 years ago when I rebuilt my 2.7. I am still running CIS today. There are reconditioned used parts available. You can get new injectors and airboxes. If I had to rebuild my engine today or was looking at a major CIS rebuild, I think I would be chasing an EFI refit on a common plenum intake (or ITB's). There are many more affordable options today versus 12 years ago.

[Reiver]

I am amazed at how well they run and hold up with little to no adjustment. My 40 year old CIS runs perfectly (knock wood) and efficiently with good gas mileage and when I put my foot in it.

I could go with carbs for less mileage and a miniscule take off boost and then have to play the balancing/adjusting game...no.

EFI, yes, if everything went south seriously but I'd be more inclined to repair whatever needed doing as it works so well as is.

[Jeff Alton]

Good reliable system, as long as someone has not tried to "fix" it in the past with a work around...


Cheers

[Dpmulvan]

I imagine there’s still a bunch of cis systems out there sitting on shelves as spares. Think I have 3 or 4 laying around.

[boyt911sc]

Originally Posted by cmovic

I'm curious what others think about the current and future state of CIS induction.

I've been driving my '78 SC with no troubles for almost 30 years (eek) until this summer. I was more than a little shocked to find out the Aux Air Valve that failed was a $1300 part ($1100 on Pelican). Browsing the catalog I see a lot of darned expensive and NLA parts, making me wonder if I should count on CIS going forward or start thinking about alternatives. My particular application is a track car so I don't have have smog/inspection concerns.

Thanks for any input.
-Vic

Vic,

How did you test the AAV? I got several AAV that were tested and confirmed good in case you still need one.





Tony

[cmovic]

Originally Posted by boyt911sc

Vic,

How did you test the AAV? I got several AAV that were tested and confirmed good in case you still need one.

Tony

I misspoke - it was the aux air regulator that went bad. Symptoms were high idle but ultimately a local shop diagnosed and repaired it.

-Vic

[cmovic]

Originally Posted by Dpmulvan

I imagine there’s still a bunch of cis systems out there sitting on shelves as spares. Think I have 3 or 4 laying around.

Yeah I've thought about that too. Still kicking myself for selling a complete '78 SC engine for $1k back in '04. But the downside to used parts and keeping spares is that the car is more likely to be a project than a fun toy.

-Vic

[cmovic]

Thanks all for the input to date. I'm leaning toward keeping the CIS for now. That makes several of my rebuild decisions simpler. If it does go south, the full EFI seems like a good plan. This thread was interesting: rhd-itb-megasquirt-install

-Vic

[shoooo32]

I've got over 50k miles on my rebuilt '78 targa 3.2ss with stock CIS. It's easy to tune the mixture with a wideband O2 and makes plenty of power for my taste. It's been dead reliable, 20mpg, and the only reason I need my laptop on road trips is to answer emails

[safe]

Originally Posted by cmovic

My particular application is a track car so I don't have have smog/inspection concerns.

Thanks for any input.
-Vic

If you go EFI you will just be kicking yourself screaming "WHY DIDN'T I DO THIS 10 YEARS AGO!!!".

Forget about Megascrap, get a good commercial alternative, they aren't expensive anymore. They have support and tuners willing to work on them.

[john walker's workshop]

When your efi takes a dump in the boonies, you better know how to deal with it, because most shops won't know jack about it.

[safe]

Originally Posted by john walker's workshop

When your efi takes a dump in the boonies, you better know how to deal with it, because most shops won't know jack about it.

I would be a lot more worried about finding someone who has even the remotest idea of how a k-jet works.
At least over here every kid in the boonies who has a modified car can hook up a laptop and fiddle with their boost maps...

These days EFIs has bluetooth and with an app on your phone you can easily connect and get error messages and see faulty signal.
I've ran an aftermarket EFI on my first car for 15 years (no fancy bluetooth) and it has let me down once and that was due to corrosion on the old ceramic fuses panel in the engine bay.
As long as there an crank shaft signal its incredibly resilient.

[targa72e]

I did my first Programable EFI set up over 20 years ago. I used a 3.2 intake on a 3.0 SC. Used in my track and street car. I eventually sold the whole system to my friend. He is still running it today. It has not been touched since it was installed on his car 12 years ago. If the ECU died today there are tons of options that could replace it.

john

[cmovic]

Originally Posted by safe

I would be a lot more worried about finding someone who has even the remotest idea of how a k-jet works.
At least over here every kid in the boonies who has a modified car can hook up a laptop and fiddle with their boost maps...

These days EFIs has bluetooth and with an app on your phone you can easily connect and get error messages and see faulty signal.
I've ran an aftermarket EFI on my first car for 15 years (no fancy bluetooth) and it has let me down once and that was due to corrosion on the old ceramic fuses panel in the engine bay.
As long as there an crank shaft signal its incredibly resilient.

+1 on this. My local CIS guru is retired. I know people who have sold their CIS based cars because shops can't diagnose and fix issues. With enough time I could probably figure it out and get good at troubleshooting it, but I'd rather be driving than debugging.

[930cabman]

Originally Posted by john walker's workshop

When your efi takes a dump in the boonies, you better know how to deal with it, because most shops won't know jack about it.

Nobody will be able to work on any of them. Time to flatbed her

[ahh911]

Since I've owned, 81sc cis stock, 20000 miles, not a hiccup. Don't know what others are going through, but I am sure this has been an easier ride for me than any other conversion.

[47silver]

75 cis no problems (after air box leak found) many years ago.

[safe]

Well, if your CSI works good, maybe you will be fine, until you aren't.
But if you want to extract all the horsetorque in the engine, you do that with EFI.

Another thing is the ease of adjustment when you get more and more ethanol in the fuel. So instead of whining about the ethanol fuel you realize that the more ethanol there is the better the car goes!

[cmovic]

Originally Posted by safe

Well, if your CSI works good, maybe you will be fine, until you aren't.
But if you want to extract all the horsetorque in the engine, you do that with EFI.

Another thing is the ease of adjustment when you get more and more ethanol in the fuel. So instead of whining about the ethanol fuel you realize that the more ethanol there is the better the car goes!

OK, I’ll bite. What are the recommended EFI setups for say a 3.2SS engine? Or pointers to threads where this subject has been addressed.