Project Christine slightly-less-slo Hackensteinberg

[theholycow]

Edit 2011-08-15: See my photo albums, videos, and other links about the car:
https://sites.google.com/site/hackensteinberg

Original post:
This is to be the thread for the Buick's fuel system.

Review/history:
- Car: 1980 Buick LeSabre Limited with Quadrajet-carbureted 4.1L V6
- Previous project: Replaced TH350 slushbox with Borg Warner/Tremec T5 5 speed manual

I really love driving it but the driveability symptoms are killing me. My plan all along has been to convert it to fuel injection. Last autumn and winter I spent many months researching the transmission project...this winter it's February and I've only gotten started on the fuel injection project research. I think it's going to be an easier and smaller project, at least.

Our resident automotive engineer Rope-Pusher was kind enough to PM me, and I figured that instead it is worth starting a thread so we can share with everybody.

The PMs are very long but we're being very thorough (I hope). I'll post them in the next two posts (unless someone posts in this thread while I'm copypasting them!).

[theholycow]

I know you are having driveability issues with your car, but switching to fuel injection is a serious proposition. What exactly is your car doing / not doing that is pushing you to consider making this change? Are the issues only when cold, or also when warm? Are your spark plugs normal, or do they show signs of fouling out? Have you ruled out ignition issues? Do you know if your float is sticking or leaking? In your religious conversion to the Amish faith, were there any extra wiring connectors that might have been supplying input toward control of the carb or ignition? Can you use the ignition switch to get number codes to show? If so, what do those codes suggest?

What is the history of the vehicle - has it sat around for months or more unused? Did it exhibit any of the current symptoms when it was a slushie? Was it driven as a slushie recently before the conversion?

Before they all die off, it might be a good idea to find a cave man veterinarian who still remembers working on dinosaurs and who can throw it on some ancient apparatus that could show if it's ignition, carburetion, a collapsing lifter, low compression, etc. that is causing the issues.

Thanks for the PM! I really appreciate your input and thoughts on matters like this, you are truly a great resource.

Do you mind if I put these PMs in a thread so that everybody can benefit from them? I won't do it until you approve.

My plan all along is to convert to fool infection, partly for its advantages (easy starting, adaptability, lack of maintenance, computerized data display and logging) but mainly because I'm just more comfortable with it and it is part of my ideal car.

There's also the issue of servicing it; I am pretty confident at my ability to troubleshoot fuel injection, but I'm terrible with carburetors and there are few people who are any good with them.

Finally, there's also the learning experience of doing it...I learned so much on the Amish transmixer project and I'd like to learn more! Granted, GM already did all of the engineering (unlike the T5 project) so it seems most of what I'll have to do is just bolt stuff on, but for what it lacks in learning experience, at least it'll be inexpensive.

If I don't switch to FI then I'll need to rebuild the carburetor (or get one that's already rebuilt). To do that right is going to cost most of what I think the FI project will cost.

Addressing some of your points...

Issues with the car (what it's doing/not doing):
1. I can never get the idle to behave. Cold, warm, doesn't matter. It's somewhat unpredictable but always high...sometimes a little, sometimes a lot.

2. Skipping/misfiring that I'm pretty sure is a fuel supply issue, which I may have to invest in whether or not I convert. Cold or warm engine doesn't matter and we haven't had warm weather since it got worse.
2a: I'm going to replace the fuel filter soon and see if it helps (as well as reducing cranking time when cold).
2b: I think this could also be the mechanical fuel pump...can a mechanical fuel pump get weak, or do they work fine until they totally die?

3. I'm pretty sure it's not making even the meager amount of power it should.

4. I can't get the fuel economy I want, but I'm pretty confident that FI will allow me to get there. All my hypermiling tricks are counterproductive on a carburetor and I don't enjoy saving fuel with the carburetor...I enjoy it with FI.

I have at least made peace with starting the car. It is pretty predictable now; I can operate it the proper way (pedal to the floor once then ignore it) and all I have to do is crank it for 30-60 seconds and it fires right up and stays running. At least now it's starting reasonably and not stalling.

Spark plugs: I ought to check them.

Ignition issues: Have not rules out but that's another system that will be mostly replaced as part of the FI project. I put on a new cheap distributor cap and rotor, wires, and plugs a few months before starting the T5 project.

Float: Have not investigated but based on my research, my year should have a pretty decently bulletproof float...it certainly could be at fault though!

Extra wiring connectors: Definitely not. I found a few while doing the project but I wasn't the one who disconnected them and I think they go to other systems. The carb doesn't have any wiring (well, there's the air conditioning throttle solenoid) and the ignition doesn't have any disconnected connectors.

Codes: No computer. Mine is all old-school. The computer showed up in 1981.

History:
- The first 12 years it was garaged, then it was outdoors for another 12 years.
- I think generally it sat for a week at a time and then drove less than 5 miles round-trip.
- I got it with 35,000 miles when it was 24 years old.
- I drove it often for the next 2 years and it had a very fast idle and sometimes stalled, but I don't remember if there was anything else.
- Then it sat in my yard for 3 years; at least once a month I'd idle it for a half hour and drive it two miles, getting up to 60mph for a few seconds (except when it couldn't; the additional driveability issues were then improved but not eliminated by replacing the fuel filter).

It's tough finding someone around here who is willing to care about an old, dirty, stick shift project car enough to properly diagnose it. In fact, it's pretty tough finding anyone to diagnose anything around here...mechanics want to let your car rot in their parking lot for weeks, then work on it for a half hour and get it the hell out of their shop. I can at least test compression myself, though, and I can research what it takes to diagnose lifters and valve issues.

[theholycow]

THC - Shirley Yukon posed this FN ewe wand.

Sounds tummy like maybe the high-idling issue has been around for a while before the conversion. I don't know much of anything about your car in particular, but there were times when GM used an idle stop solenoid to hold the throttle plate open further when the car was running, but allow it to close further when de-energized to prevent run-on after shut-down. They also sometimes had a coolant activated switch that disabled distributor vacuum advance when the car was warm (to reduce oxides of nitrogen emissions). I also can't say when they went to feedback carburetion to control the mixture during closed-loop operation, but early examples of this didn't involve the idle circuit or the secondaries. Still, if you've got an O2 sensor there must be some feedback loop to the carb. Also, there may be exposed or hidden idle mixture screw(s). They would be down near the base of the carb, maybe with plastic limiting caps or maybe even hidden behind steel plugs driven into the bore(s).

If the float level is off, fuel metering will be off and maybe even raw fuel can overflow and drip down on top of the throttle plates. You should be able to see if this is happening if you look down on the uncovered carb while the engine is idling.

Back in the day, a guy with a Sun engine analyzer could pinpoint which cylinders were giving problems, what the problems might be (spark, fuel or mechanical), etc. - like a cardiologist reading an EKG. A friend of mine got a job when he graduated from Ferris State's auto school because there was a Sun machine languishing in the corner of a shop that none of the older mechanics wanted to learn to use (goes back to getting paid for fixing things, but not for diagnosing things. My buddy arranged to get paid an hourly rate rather than getting paid based on a rate times the allotted time for a given repair.)

I hear that there are much simplified fool ingestion systems available now, that self-teach themselves the particular metering needs of a given engine. That would make things a lot easier for you, but I don't know what the cost premium is for such systems. Without that help, it's a lot of work to get the fuel metering right for the entire operating envelope of an engine, especially if you give a rat's rear about something like emissions or fuel mileage. Extra fuel can cover up a lot of driveability issues that lean mixtures would not be so forgiving about.

Idle stop solenoid: I wish. My car doesn't have it but I've read all about it.

Coolant-activated switch that disabled distributor vacuum advance: I may have this. I have something like that, in that position, but I thought it only had vacuum lines going to it.

O2 sensor: My car doesn't have it.

Idle screws: Yup, hidden behind steel plugs. I may try to get to those. I fear that adjusting them is only going to make things worse; this carb is designed to never need idle speed adjustment, so hacking around with it may clear one symptom and exacerbate another. Still it's worth a try - IF I'm willing to commit to removing and reinstalling the carb. Unfortunately I fear that the base could be warped but still sealed, but after I monkey with it it'll never seal again. It's common for Quadrajets although by my year they were reinforced to prevent it.

If the float level is off and fuel is overflowing into the throttle, wouldn't I get some smoke sometimes? I have been assuming that any float problem causing my symptoms would indicate a lean mixture. I'll have to look into it (literally) to see if there's any fuel dripping.

That Sun engine analyzer sounds interesting...I'll have to try to think of a reasonable way to find out who might be able to do something like that.

I'm pretty confident that the SFI system from a 1986-1988 FWD Buick 3.8 will bolt on and run perfectly, or at worst need bigger injectors and a tune...all I need is a wrecked/dead transmission/rusted out/etc donor, like my transmission donor was. I have looked into aftermarket FI systems but they're $1000+.

[Rope-Pusher]

I'd think that the 3.8L SFI wouldn't be calibrated for your engine. I'd also think it would want a crank position sensor and a half-dozen other sensors and wiring for them, an electric in-tank fuel pump, a fuel tank to fit it, etc.... ...getting your carb, assuming that's all that the problem is, to run correctly should be mucho easiero and cheapero (See, I've picked up some Spanish thru my substitute teaching assignments)

[theholycow]

Yup, it'll definitely need most of those things as well as (I think) all new fuel lines.