93dxeg

Hey everyone, wish my first post was more exciting but it is what it is! I just bought a 86 cutlass supreme with a stock 307, car runs and drives great but the problem is when im using the ac if i come to a stop in gear the car will start to stumble (die) and shut off! I am new to having a carb always had fuel injected cars in the past! So please bear with me! A few things that may help are the voltage drops to around 10 when ac is on, im goin to get a cs-144 alt. Soon! And also alot of the emmission equipment was removed from the car before i got it, vacuum ball was removed also! I know this pic doesnt help, but it doesnt hurt! Thanks, Ron
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Nasty455

Usually there is an electrical connection at the carb with a plunger.it raises the idle slightly when the A/C is switched on.
Probably the wire is disconnected or the plunger is adjusted incorrectly.

henryk8398

Nice car! If that's a VIN Y 307, there is no electrical idle solenoid to boost the idle. It's vacuum and is called an Idle Load Compensator (ILC). It's likely either missing or not adjusted properly. It is a diaphragm that senses a drop in vacuum at idle (from the ac turning on or turning the steering wheel against a stop) and pushes out a plunger. It's long since discontinued. Take a picture of your engine, specifically near the carburetor and post it here.

This is what an ILC looks like:

http://forums.aaca.org/f177/85-84-83...le-281042.html

93dxeg

Thanks the only two sensors i see on carb are what i believe are the TPS and MC solenoid. a few more things to add the car idles a little rough wether ac is on or not, very small fluctuation, but only cuts off with ac on. It also idles high about 1200, i checked for vacuum leaks and didnt find any and replaced vacuum hoses and caps at that time.

93dxeg

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Im assuming the ilc needs a vacuum line connected to either carb or intake manifold somewhere? And possibly adjusted?

Lady72nRob71

Nice looking car. I have a stock 86 with 307 and the A/C always worked fine even at 700RPM idle. Much of the issues stem from the emission stuff being removed. If the computer isnt happy, then the ILC will not function, as it controls a solenoid, supplying vacuum to the ILC. In fact, this engine practically NEEDS all the emission stuff working in order for it to run correctly. Other owners have removed emission stuff in hopes to increase power, ending up only making things worse. The 307 is a finicky beast. Only way to really get more power from it is to replace it with an older 350. They will even work happy with the computer!

The vacuum ball is needed to keep the AC controls from going wonky when vacuum is low.

The low voltage at idle could be from a multitude of issues. The stock alternator will do fine with it, IF it is not bad and you are not running electric fans or fuel pumps.

The high idle speed could be from the ILC being engaged (no vac). I once had an O2 issue tht kept the computer in open loop mode. During that time, the ILC would never engage and lower the idle. Once the computer closes loop and is happy the idle went down. So see what is holding the throttle open - the ILC or the little adjusting screw. on the carb body / linkage.

EDIT - just saw your pics. The ILC is no longer being used, holding your idle high. It normally connects to a computer controlled solenoid. You might need to replace it with an electric ILC and wire it to the AC clutch. However, you need to get it to idle happily at 700RPM in drive.
--You could hook that thing right to manifold vacuum and see what happens. Your idle might go down but may not increase the speed correctly... Does not hurt to try and find out!

93dxeg

Just hooked it up to the manifold, idle went down, i tried adjusting ilc and got it where car didnt want to start, then went in other direction and got car running and idling not great though! I looked at vacuum diagram under the hood and realized they took of almost everything! And guess what the cars still slow haha! And about the 350 i picked up a 70 olds 350 motor, saving for parts the goals to have motor machined and assembled by september but thats a whole diff. Can of worms!

Lady72nRob71

Id figure it went down but not surprised it starts hard. Normally the car starts on a faster idle and as soon as it does start, the computer energizes the solenoide and pulls the ILC down low. It does this in about 3 seconds and allows the engine to start up effortlessly up even after sitting 9-10 hours without a pedal pump.

I know they took of most everything cause you can see the valve covers.
Here is how it would normally look:

No surprise it is still slow. Now it is slow and tempermental.

Good score on the 350 - great year, too. Get it ready and you will have a fun Olds!

I love this body style, just never liked the 307.

93dxeg

How would i do an electric ilc, parts, do you think this would help? Or how about a non cc carb and hei distributor this would get rid of computer? I dont mind buying parts and it would be great if i could transfer them to my 350 when its ready!

Lady72nRob71

A non-ccc carb and disty will be helpful and can be used on your 350 when you are ready. Carb might need rejetting, but thats an easy mod (I think). I bet these will help your drivability issues a lot.

Rickman48

X 2!!

ThePackRat

If you go the non-CCC feedback route with an older distributor & carb .....

You might want to invest in a kit that will retain the lockup torque converter clutch function.

Been there done exactly this & while the car ran the best it EVER did being 100% off the CCC system .....

Looking back I think this contributed to me killing the already rebuilt trans that was in it.
(course' one could simply look at one of those POS the wrong way & kill it)

FWIW ... I was also using an electric idle compensator wired into the a/c wire.

I replaced the junk TH200 with a rebuilt TH350 I already had.

I really wish I would have built up a 2004R w/a good converter & 3.73's out back. (still had the stock 2.14's)

I think it really would have been pretty snappy for a 307 ... as in my case going off all the CCC stuff made my particular motor very happy.

93dxeg

So what off the shelve carb would work for the 307 and could be modded to work for the 350 OLDS down the road, if it matters the 350 will have flat-tops ported #7 heads and as much cam as possible while retaining ac! And also are there any distributors i should stay away from, where would i find that lock up kit? Id like a carb thats pretty common so it wont be a headache finding a decent carb guy when i bave to get it tuned.

ThePackRat

Carb wise I'd look for a 1977-1979 350/403 carb.

A 1980 307/350 carb should work as well (last year before CCC).

I used to think the older ones were generally the better ones ... but I've since learned the later castings were better. I believe all the later ones were 800 CFM units as well. Perhaps it might be more appropriate to say "they HAVE the potential to be 800 CFM" ... since most were crippled from the factory.

The 1977-1980 stuff also has the same style linkage as the later 307 stuff IIRC ... vs some of the older stuff.

Nothing special about these carbs - there were a ton of them made & Oldsmobile sales were super strong in these years. Adding even more carbs out there to choose from ... a lot of 403's went into Buick's & Pontiac's (B&P) in 1977-1979 as well. Additionally ... I believe an Olds 350 or a 403 may have even been mandatory in bigger motor B&P stuff sold in California in that era. Bottom line ... there was definitely no shortage of these carbs out there.

There are a few lockup kits out there ... Summit - Jegs - trans builders etc etc ... but I don't have a lot of knowledge in regards to them.

There was a builder (with a good rep IIRC) that had a webpage describing the different type of lockup kits out there & the pro's & con's of each.

Unfortunately that's on a non-working PC at the moment & a quick search isn't finding it.

IIRC, the best kit was one that worked similar to non CCC equipped OEM applications. It may have even used an OEM component or two ... can't recall 100%. You may even be able to use _ALL_ OEM parts to accomplish this. Again ... my memory is a bit fuzzy on it.

Distributor wise ...

Any standard Olds HEI from 1975-1980 should be fine.

Do avoid 1977-1978 Toro ones tho ... as one of those if not both of those years had some sort of unique to the Toro ignition system.

Pretty much any HEI could use some improvement for the best performance.

Below is a link that links to some tech articles that have made their way around the internet.

http://forums.corvetteforum.com/c3-t...long-post.html

Anyone that has ever pondered & researched .....

"Ported or manifold vacuum advance" has stumbled upon this stuff many times & the countless never-ending debates over it.

Regardless of your preferred poison (ported/manifold) ... there is some good info on advance curves - weights - vacuum advance cans etc etc etc.

My 307 loved being off the computer.

And this was doing pretty much ZERO tweaks to the carb or distributor.

Only downfall I experienced as I previously mentioned .....

Was not having the lockup working.

This drives up trans temps ...

Which may have very well helped kill my trans later on.

Knowing what I know now vs what I didn't know then .....

Is why I mentioned it so you don't make the same mistake.

A trans cooler might not be a bad idea either.

93dxeg

Thanks for all the information, will the 75-80 hei work with a 72" 350? I love the idea of losing the computer, sounds like it will make things simpler! Im still wondering how this will keep car from stalling with ac on in gear, what do the non ccc cars use to control idle when accessories are being used? I will def. Consider a trans-cooler especially knowing when the 350/350 setup is done i will be driving like i stole it! Thanks again!

Lady72nRob71

If you go to a non CCC carb and disty, the engine will probably be happy enough to not need an idle bumper. My 72 350 ran fine with AC and no idle bumper.
The CCC carb and disty are designed to be told what to do by the computer - carb mixture and ignition timing. They do have a limp mode in case the CCC fails, but then it is drivable - just not very well. Replace the carb and disty with non CCC parts and the engine should run much better.

93dxeg

Ok will order dist. This weekend and on the lookout for a non cc quadrajet! Thanks everyone for the help, im sure i'll be back with questions once parts arrive.