Sansveni

I have an 1983 Oldsmobile 88 with a CCC Quadrajet and an Olds 307 engine that I recently replaced the timing chain on.

I should mention that I only have about a year's experience with working on cars, and this is my first carbureted car.

When I start the engine, it idles very high. I noticed that the choke does open up, although not all the way (perhaps 50-70% of the way?).

I got some online help and adjusted the choke thermostatic coil by turning it clockwise until the the choke opened completely, and then turning it counterclockwise and until it shuts, and then turning it back another 5 degrees or so. I then gradually turned the choke idle screw back (counterclockwise), racked the throttle, and then started the engine. I ended up loosening it all the way. No luck.

At one time it seemed like I was making progress, but part of the advice I got included unplugging the electric choke. Being new to this, I assumed it was the closest wire next to the choke. I unplugged it, and the engine idled much slower, but after a few engine starts, it stopped starting. I pulled a Code 23, after which I realized I had unplugged the mixture control solenoid. I plugged it back in, and I went back to square one with the original problem. I then looked up pictures of an electric choke. I don't have one. Whoops.

It has a code 41 stored in the ECM. Apparently it's related to the EST System and means: "no distributor reference pulses to the ECM at specified engine vacuum."

The car came with the distributor cap off, and I initially forgot to plug in some wires in the distributor (causing the car not to start), so maybe this is code was tripped then?

Pictures of my carburetor: http://imgur.com/a/GrGM4

I noticed that the rear choke pulloff (circled here: http://imgur.com/9mUYmPI ) has two vacuum ports leading out of it. One of them is connected, but the other is open and I can't find where that is supposed to be plugged in. The rear choke does seem to pull back and move the choke a like it's supposed to, just not completely open.

The throttle return spring is old and I am going to replace it, but in the meantime, I have made sure that the throttle is pushed all the way closed each time I start the car.

Since the engine sounds so noisy and fast-rev'd, I am scared to run the engine for more than a few seconds each time.

Any help will be greatly appreciated.

olds 307 and 403

If your choke isn't opening all the way, buy a replacement hot air choke coil. They do wear out, just make sure the new one is set correctly. Plug the open port till you find where it goes.

joe_padavano

Unfortunately, the CCC system is far more complex than a normal carb. Frankly, it is not a good "first time" carb for the inexperienced to work on. You MUST get the factory Chassis Service Manual and follow the CCC adjustment process EXACTLY. If you don't, you'll never get this car to run right. The stock choke coil has an indexing notch that only allows it to fit into the choke housing in one orientation. It isn't designed to allow adjustment and if your carb doesn't have this tab on the choke housing, someone has changed it.

Fast idle speed is controlled by the choke. If the carb is stuck on fast idle, either the choke isn't functioning properly, the linkage is jammed, or the fast idle screw is turned too far in. You should be able to move the fast idle cam with your finger to lower the idle speed. If not, there is something jammed.

Curb idle is set using the Idle Load Compensator adjusting screw, NOT the idle speed screw. The ILC is vacuum operated and controlled by the ECU to set idle speed based on load (like A/C on or not). The system is designed so that when you shut the engine off, the ILC retracts and the throttle blades close further to prevent dieseling.

rustbukt307

Don't mean to hijack the thread here, but I was having a similar problem with my 307 powered 1989 Cadillac. In my case the fast idle cam did physically go down and none of the linkages by the choke seemed jammed at all. It took me playing with the linkages on the driver's side before the idle dropped. I didn't feel anything free-up or come back but I'm not sure what I may or may not have done to help that idle drop.

joe_padavano

There is a wire harness bundle that runs behind the carb. This is the harness that connects the engine harness to the HVAC harness. On my car this harness got moved and wedged under the secondary throttle arm on the carb, causing idle to be high. Took me a little while to find this. Fortunately yanking it out "fixed" the problem.

And if you didn't mean to hijack the thread, why did you?

rustbukt307

Desperate times call for desperate measures! I can check to see if anything might have gotten in the way, thanks for the suggestion.

Sansveni

Thanks for your replies. I've been caught up at work this week and haven't had a chance to reply. I did order a Chassis Service Manual and its on its way. I honestly thought they went under a different name so I was having trouble finding it. Thanks for the suggestion.

I didn't see any notch or tab that caused the choke thermostat coil to only fit in one direction so I suspect someone changed it. I think that I'll go ahead and get a new one.

I was surprised though when I learned that the car has a nonelectric choke -- I thought '80s Olds 88s were designed to run with electric chokes? If I am replacing the coil anyway, should I buy an electric choke?

Thanks.

olds 307 and 403

Good call, I have seen them go bad and not open all the way. Make sure the tubes in the intake aren't rotted through and they are all connected. Lubing the linkages is another good idea as they can stick and leave the idle high.

sailinghudson25

A few things....


-check all your hose are in good shape, a major leak could be causing you problems. Finding out what vacuum you have at idle may be helpful here too.


-play with your choke a bit. Close it all the way. See how the linkage raises the idle speed up. See how it locks out the secondaries. This might be helpful to you.


-check that your butterfly valves are actual close as said before.


-make sure the PCV valve and hose is in good shape. Remove the PCV valve and clean it with some card cleaner and rattle it clean. Sometimes just replacing a PCV messes with idle speed, when the wrong pcv valve is used.


-somewhat large changes in timing advance change the idle speed. Investigate that error code. Could be a bad Manifold air pressure sensor, or a bad hose to it. Knowing your actual igniton advance and actual idle speed would be helpful here.


-spraying a bit of carb cleaner in various spots ontop of the engine reveals vacuum leaks if you have one


Having a significant leakage of air without going through the carb results in a lean mixture, does it run high and rough, or just seems high.....

Sansveni

UPDATE: I've been really busy with school and work, so I haven't had a chance to work on my car till last week. I do want to update you all so people know whether what you suggested works or not (confession: I was on another car forum where someone was saying "I wish all these people with car problems would come back and tell us whether what we suggested ended up working or not." Guilty).

I did end up changing the choke thermostat coil, and now I can see that the old one was definitely faulty. After about 8-10 seconds, the engine noticeably "kicks" down to a lower idle. However, the coil apparently was not the only problem.

It now dies whenever I put it into drive (the first time I did this, it actually stayed running, just barely, and I slowly started inching down the driveway, at the end of which I put it back into park and it died). I figured it was because I'd adjusted the base idle too low (I was later told not to mess around with the idle screws like that since my problem was probably the choke, but it was too late).

I screwed the base idle screw in a bit, and it does seem to idle higher now:


Yeah, it does sound rough! Maybe I have air leaking in. I took the carburetor off when I first bought the car to clean it, but did not replace the base gasket.

During these adjustments, I have not bothered putting the car in drive anymore, and have just let the engine run a bit. Well, I discovered that it dies after about 30 seconds, and if I let that happen, it will be very hard to start again for at least a day. I should probably start a new thread on this, but the research I've done suggests leaky fuel bowl or some other fuel problem.

I'm considering doing a carb rebuild.