My New-to-me 1987 CE Wagon

That is nice, congrats!

 

That is sharp, congrats

 

Great news! That is a very nice looking Chevy

 

Very nice! I second the factory service manual. It's super thick on the CCC system and details exactly how to make it work. Once I followed all of the steps and found the bad metering solenoid in the carb, it ran like a brand new car. Never would have thought to check it without the book (car just bogged above 45MPH).

Seeing all of these 80's wagons lately makes me miss my old 1990 Custom Cruiser with 307...

 

Those solenoids, and the TPS sensors, were those carbs' Achilles Heel. And, if you knocked off the idle mix screw caps, it made it easier to get your idle mix set, then set the solenoid at idle for 30% dwell. My old boss could get a Q-Jet down to less than 20 ppm HC and under 1/2% CO at idle after rebuilding. It used to blow away the emission testers and the inspector that came around to the shops.

 

Thanks for the comments everyone!

Service manuals arrived in the mail last week. I think elB and Silvertwinkiehobo are onto something (thanks for the suggestions!). When starting off from a red light, she hesitates (wants to stall but doesn't) for several seconds; and then off we go.

My mind is still on the possibility of another vacuum leak somewhere. A couple of days ago I was on the highway (~60 mph) with the AC on; fan speed one notch above "off". Upon climbing a steep hill, I found it necessary to nearly floor it to maintain speed (is this normal for the 307's of the '80's era? This is my first and I've heard they are a bit sluggish compared to the 350's of the '70's). Anyway, while climbing this hill, the fan suddenly quit. I held my hand to the dash vent and noticed that as I crested the top of the hill and was letting off on the accelerator, the fan gradually came back on.

Despite this, she's still fun to drive. Yesterday on my way home she broke 25,000.

Matt

 

Are you saying you didn't feel air at the vents? What you described is the problem that your one-way valve on the HVAC vacuum line is bad, so instead of having constant vacuum from the reservoir (the black plastic ball with the vacuum lines), the engine vacuum is constantly drawing until you open the throttle. At that point, the vacuum goes low, so the vacuum doors revert to the fail position, which is defrost. Once the throttle is back to idle, the vacuum rises again, and the doors go back to the vent position.

 

Does anyone have a pic of that one-way valve? I can't seem to find one online. I think GM calls it a vacuum isolation valve.

 

Flooring it to maintain speed up a hill isn't normal. It's sluggish a bit compared to a 350 or 403, but mine could still get out of its own way unless you're climbing Grapevine or something serious and trying to maintain 75+ MPH.

And the dash vents falling off sounds exactly like the check valve is bad or missing - when you open the throttle more and more the vacuum signal drops more and more. The check valve is a small plastic cylinder that has full manifold vacuum on one end and the other end going into the firewall, unless these cars had it on the inside of the firewall like some other GM cars did over the years (I can't remember and unfortunately do not have any pictures handy).

 

The Eighties ones had full vac at one port, reserved vac at the second port leading to the reservoir, and the third leads to the HVAC controls. When they go bad or the reservoir leaks, you get the effect I described.

 

Dorman P/N 47150, called a Two Way Check Valve. The large port goes to manifold vacuum. The smaller straight port goes to the vacuum storage ball. The right angle port goes to the HVAC control head. This ensures that the storage ball maintains enough vacuum to operate the HVAC system doors when the engine is at wide open throttle and manifold vacuum drops to zero. When vacuum drops, a failed check valve causes the HVAC doors to close, diverting airflow to the default positions of defroster vents and floor vents. You might want to see if that's your problem.

By the way, my 84 and 86 both required me to nearly floor the throttle going up hills, along with trans downshifting to third.

Of course, I'm used to big block cars...

 

That's the one.

 

Absolutely beautiful wagon, Matt.
Your stumbling / hesitation issue sounds similar to what the Way Back Machine was doing, when cold. Fixed now, with the new carb.

 

That is possible, if the carb was untouched. Fark it. Yank out the CCC junk, and pop on a late Seventies Q-Jet.












Just kidding. But if the carb is untouched, perhaps just freshening the main gaskets, accel pump plunger or gasket, a new filter and a dial-in could be just the ticket to what ails it.

 

Catching up, here. Thanks EVERYONE for the advice and info. I hope this check valve is still readily available.

Yes Andrew, that's exactly what I was trying to describe; all air flow (regardless of whether the AC is running) diverts to the windshield and floor vents simultaneously while I am under heavy throttle. I typically leave the control setting at "vent", then switch it to "off" when I get home and park the car. It was hot enough yesterday to run the AC, which still blows cold thank goodness, just not always in the direction I prefer lol.

Now, my cruise control quit working. It was working fine when I first got the wagon, but yesterday it would not catch. I thought initially my cruise control was also vacuum controlled, which could explain it suddenly quitting on me. But then I read somewhere that by '87 the cruise control was electronically controlled. Does anyone know the answer to this?

Anyway, the sluggishness and hesitation has improved notably since I started this thread. The carb has essentially been rebuilt and it was discovered my catalytic converter was shot. I also had it "smoked" to check for vacuum leaks and none were found, but I suspect this only tested the lines under the hood and not under the dash. Reading up on the CCC system is also still on my to-do list. If only I was independently wealthy and didn't have to work, I'd have more time to devote to this lol.

 

The picture and P/N I posted is straight from RockAuto.

 

Thought I'd offer an update here, if there's anyone still in the audience.

I'm driving the wagon nearly every day now, to-and-from work and to the grocery store. The former is a nice mix of around-town and highway driving. It's such a fun car to drive!

Temperature gauge is fixed! Turns out it was the gauge at the dashboard itself that was bad. Found another dash cluster, got the gauge swapped out and bingo it works!

I've not yet investigated the check valve issue, so I still experience changes in "wind direction" regarding the AC air flow when under heavy throttle versus coasting/idling. (Question: Is that check valve located up under the dash somewhere?).

Slight hesitation when accelerating from a stand-still prevails, but not as bad as when it first passed smog. One new disappointment is that the cruise control is starting to fail. It worked great the first couple of times I used it, but lately it's not holding at all. I thought it was still of the vacuum era, but I think I translated my options codes to find that it may be "electronic". I'd love to get this fixed before November when I'm hoping to drive it up to L.A. That would be the furthest I've taken it so far. I'm at 25,7xx miles as of today. The last two tanks have averaged 13.5 mpg in mixed city/highway driving, usually with the AC running.