Project Dumpster Fire - A hole into which one throws money [UPDATED]

[AkioOhtori]

So it has been a while since I've done a Project Dumpster Fire, my 1984 Saab 900 that I've owned, on and off, for 19 years, update. I guess technically I've never done one, now that Kinja Oppo is ded.

Anyway, when we last left my Dumpster Fire it was actually running pretty well following the installation of a freshly cleaned gas tank and a new secondary fuel pump. After that, I finally bit the (financial) bullet and installed a wide-band AF meter so I could begin to quantify the issues the car was having on the road.

Good news is the AF meter works great. Even better news is the car sits at 14.7 AFR (normal) most of the time. Even better news is every time I feel like it is performing like crap, this is now being confirmed by the AF Meter. When I do a sudden throttle change the AF raito spikes into the 18-19 range (lean) and hangs there until I get a surge and it settles back in at 14.7. While this means there is a problem, which sucks, it also means I now have data to support what the butt dyno was telling me: I have a fueling problem.

The bad news is there is pretty much only one component that could be at fault: The CIS fuel distributor. Specifically I suspect the fuel plunger, which is the device specifically responsible for metering fuel based on air entering the system. My suspicion is it is hanging due to wear or being gunked up.

Worst news? Yeah... those ain't cheap to fix or replace

Rebuild kits cost around $90 and I have a low degree of confidence I'd be able to repair it.

A professional rebuild runs around $600 and takes about two months.

An already rebuilt one goes for around $800.

Great....

So the way I see it I have three options:

• Take my existing one apart and try and get the plunger actuation smoother
• Send in one of my spares for a rebuild
• Roll the dice on another used unit

Of the three, I'm thinking of going with option four: Cry.

Ugh I know I should spend the money and just be done with it. This is pretty much literally the last running item this vehicle is lacking. A professionally rebuilt fuel distributor means this car should be at 100% mechanically again and can maybe start being reliable.

Or as reliable as a Saab can be anyway.

The nice thing about the rebuild is they take 8 weeks and they charge you when the item ships. So basically I could send it in now and pay for it in January, when maybe I'll be feeling a little more spendy. (Just paid an obscene amount to have the house pained so I'm poor AF.)

[UPDATE] Took a punt on an allegedly rebuilt one for $50. Seems like just a dude that had one in his spare parts bin, rather than a professional reseller. At $50 it is worth it just for the core and is cheaper than a rebuild kit. If it doesn't work, I'll add it to the pile. If it does, hooray!

[dieseldub]

@akioohtori Kind of makes me miss my old GTI 16V.... kind of.

CIS fuel systems can be a pain, but when they're working right, they're super, super responsive to your throttle inputs. Makes it a lot of fun.

Sadly my experience with the fuel distributors is very limited, so I'm of no help as far as what the difficulty level is on rebuilding the distributor. Still find them to be pretty fascinating. Maybe sometime I'll pickup another CIS project car and force myself to really get deep into one of these.

The mechanics of the thing appear to be simple on the surface.

[calzonegolem]

If you have spares then there is no reason to not try and get one of them working well by taking it apart and cleaning it, right?

[2 Jeeps and a Mustang wants a Fiata]

Yay! You made it over here! I really enjoy your articles and determination to make yourself go insane with your projects.

[dieseldub]

I may also add the intermittent lean issue can be a vacuum problem as well. CIS really, really hates vacuum leaks. And it can be something stupid like, say, the pipe to the brake booster. Maybe it has a crack that remains somewhat well sealed until the engine rocks on the mounts as you transition the throttle, then it leaks worse as things move. You never know. I've seen weirder things happen.

[AkioOhtori]

@dieseldub That is fair and I'll double check. I ran a leak check (pressurized smoke) on the system a while back but it wouldn't hurt to do again. Also since the problem always seems to clear up around the same RPM I'd believe a minor leak that higher vacuum causes to go away? Then again since I have the correct AF ratio in boost that doesn't really work.... Anyway. Good point and I'll do that before I pull the trigger.

[AkioOhtori]

@calzonegolem Yes and no. Probably worth pulling the existing one to see if I can clean it at all. Problem with most disassembly is exposure to air will cause the seals to swell, at which point they need to be replaced before reassembly. Seal kit runs $90.

[HoustonRunner]

@akioohtori So you just need to disassemble and clean it...in space! Aha, I've found a 5th and MUCH more expensive option for you!

[BicycleBuck]

@houstonrunner If he can't afford a trip to space, then he could do it in a bucket of fuel. Yeah! That's not dangerous AT ALL!

[HoustonRunner]

@bicyclebuck Well, that way it may live up to the name "dumpster fire"....

[BicycleBuck]

@houstonrunner It's essentially how my father set fire to and acquired a '65 Mustang. OK, to be fair, the fire started first. The bucket of kerosene was an attempt to put the fire out.

[chan]

@akioohtori I vote the middle choice

[rctothefuture]

@akioohtori I rebuilt a CIS system once. It was not fun, but if you have a clean bench and take your time, it can be done. The reason it's so expensive is that it's a tedious and labor filled task. Honestly, I wouldn't risk a used one as I'm sure it'll go bad shortly after purchase.

I'll agree on the vacuum leaks. I had a Scirocco that had a small hose that was split but you wouldn't know unless you actually had it under vacuum. Made the car run like dog shit. Replaced all the hoses and it ran like a top. I only took it apart as I sold it to a friend that had issues a few months after ownership.

[Qaaaaa]

How much have you spent on CIS stuff at this point? I am plotting to 2.0 16v swap my Cabriolet this winter, and the CIS Lambda that I have is very finicky- I have a manifold with the right injector seats but honestly, I'm probably going to go carbs and 8v ignition to run the car. CIS is cool, but frankly not worth messing with in 2020 when setting up your own EFI is easy and cheap.

Obviously carbs aren't a great option for you, but I've priced out an entire fuel system for under a grand with twin Weber DCOEs.

[HoustonRunner]

@bicyclebuck said in Project Dumpster Fire - A hole into which one throws money:

@houstonrunner It's essentially how my father set fire to and acquired a '65 Mustang. OK, to be fair, the fire started first. The bucket of kerosene was an attempt to put the fire out.

Wait, what? Oppo needs to know more about this story.

[SilentbutnotreallyDeadly]

I've mucked about with mechanical diesel injector pumps before in terms of replacing seals/partial rebuild etc.

Taking it slow, methodical and clean (a challenge on a grimy tractor and an open air workbench) and documenting each step of the removal process helped...as did the YouTube video of someone doing it!!

If I had the time and the reason...I'd give something like your CIS thing a shot...

[BicycleBuck]

@houstonrunner It was one of my last posts on Kinja. Basically, my father was working on a mustang, started an oil fire, then in his panic to put it out, grabbed the bucket which they were using to clean parts and threw the contents onto the fire. I'm not sure which would have been worse on an oil fire - a bucket of water or a bucket of kerosene. I just know what he used: Kerosene. That led to pushing the car into the street so it wouldn't burn the apartments down and a call to the fire department.

The owner wasn't too happy with the shoddy work, so that's how we ended up with a red '65 Mustang convertible. He did manage to put it back together and he drove it for a while. They divorced before he got rid of it, so I have no idea what happened to it. This all happened when we lived just off the southeast loop there in Houston.

[RallyWrench]

@akioohtori Who are you checking with for rebuilds? We use Fuel Injection Corp in Tracy, CA. Usually costs around $400, and have it back in less than 2 weeks. I had my 911s FD done with the cis-jetronic diaphragm & seal kit.

[HoustonRunner]

@bicyclebuck Wow. Sorry I missed that post, I kind of checked out on kinja in the last few days and stuck around here. Great story though.

[Urambo Tauro]

I like the DIY rebuild option. Not just to save money, but for the experience. (I've always loved taking things apart and learning up close how they work.)

[BritsnSwedes was MINIGTI]

Yes!!! I’ve been craving more SAAB content since I bought my 1998 convertible (I’m sure you’ve seen pics before)
It was somewhat neglected but had decent looking brakes and fresh tires and the salesman/owner of the lot said a friend of his had been DDing it, so I figured it had had at least some care.

Just did a few things and had my SAAB mechanic check it over and we took it on a 1500 mile trip. It’s been perfect, that little B204 2.0t is very nice.

[BritsnSwedes was MINIGTI]

@akioohtori
Also have a GORGEOUS 900 I spotted recently.

[pip bip]

@akioohtori grab a repair kit too while you're at it.