questions and problems about a 2.8

[MillenniuM]

I have a 1988 buick regal with a 2.8 engine in it, the car is great, but it usually starts at 1900-2000 rpm, and it comes down to around 700 in 5 seconds .
I'm wondering if this is normal or the car should start at around 1400rpm only (like it did before i put a new IAC).

Also I try to slow down the idle speed, the car succesfuly stays at low idle (like 650rpm in drive ) but only for a few minutes , then it goes to around 1100rpm when cold, or to 800rpm when hot.. buy sometimes the car stays at 1400rpm in neutral and it won't come down .. i try a lot of things but i don't know what it could be.

I was looking for vacuum leak.. and i found an unplugged vacuum hose, but it's well closed, but not connected where it should be, i think it's some hose that goes to transmission or transaxle but i coudn't find where it plugs!.

well thanks if someone can help me a little!!

[patgizz]

the hose to the transmission should plug in to the plenum on the front side right behind where the throttle body is bolted on

[MillenniuM]

well.. thanks i'm going to try looking there.. but i'm not sure, because the hose now is right behind the battery, and comes from the cruise control and the same throttle body and i don't know if it's long enought to reach that place.... i'm trying to get a photo today.

Do you know if the high starting idle is normal? that is a thing that gets me mad , and makes a lot of noise! everyone looks at the car when it starts!

[patgizz]

every fuel injected GM i have had idles high for a minute or so

[robby1870]

Yeah, my 3.1L, when started cold idles around 1100-1200 for a minute or so. But, did you do an idle re-learn after the new IAC?

[MillenniuM]

Yes. i've done the idle relearn hundreds of times but it's always the same, it doesn't matter if you do or don't do the idle relearn.
The problem is that the car gets higher rpm's but it won't slow down.. if gets 1500rpm you need to shut off the engine and restart to get the normal idle. I think that it could be a vacuum problem (related to the unplugged hose) but i'm not sure.
I've disconnected the canister vacuum hose and now it stays for more time at low rpm's.

[robby1870]

Yeah, the high idle does sound like a vacuum problem. I only mentioned the re-learn, cuz sometimes thats all it needs. Check all your vacuum connections and especially the one to the MAP sensor, since the line snakes back there and I have pinched that line numerous times changing the plugs or wires.

[Rhedalert]

That vacuum line you mention is a broken part of the line that goes to the HVAC controls. Do your dashboard face vents work?

The high idle could very well be a small leak on the lower or upper intake gasket, throttle body gasket, or you forgot to put the O-ring on the IAC. To test for a leaking gasket, spray some carb cleaner between the manifolds where the gasket edge is visible and listen for an rpm change

[Anonymous]

well.. thanks i'm going to try looking there.. but i'm not sure, because the hose now is right behind the battery, and comes from the cruise control and the same throttle body and i don't know if it's long enought to reach that place....

It could be the hose that connects to the vaccuum modulator. If its disconnected from the modulator and plugged your car will shift real hard though.

[MillenniuM]

well thanks! , the vacuum line diagram says something like HVAC, but the dashboard vents works all right , and the vacuum modulator hose is connected, so... i'm very confused about that hose..!, also i found that cruise control only somedays work, and somedays don't.
It is true that the car shifts hard, but only from and to 1st gear. I am trying to fix all this problems since january, when i bought this car, and everyday i found another new problem in it..!!!
Well after all it has around 150.000 miles.

I have another question about this car... (for someone who ever had one similar), Is the standard concert sound II radio as bad as mine?!? the radio has a separate power amplifier, 6 speakers and, It sounds awfuly bad!! even a $20 cassette radio with 2 speakers that i put in my old monte carlo sounds better!!

[Anonymous]

My car is an 88 and had the seperate radio, cassette/eq, pwr amp, and 6 speakers (on the drivers door there was a switch too). It actually didn't sound bad at all. Loud and clear with some bass. Something must be f@cked up with yours.

I think we need some pics of your hose thats disconnected. If you get that I should be able to find it on my car and see where it goes.

[Rhedalert]

well thanks! , the vacuum line diagram says something like HVAC, but the dashboard vents works all right , and the vacuum modulator hose is connected, so... i'm very confused about that hose..!, also i found that cruise control only somedays work, and somedays don't.
It is true that the car shifts hard, but only from and to 1st gear. I am trying to fix all this problems since january, when i bought this car, and everyday i found another new problem in it..!!!
Well after all it has around 150.000 miles.

I have another question about this car... (for someone who ever had one similar), Is the standard concert sound II radio as bad as mine?!? the radio has a separate power amplifier, 6 speakers and, It sounds awfuly bad!! even a $20 cassette radio with 2 speakers that i put in my old monte carlo sounds better!!

ok, then the vacuum line is broken closer to the vacuum resevoir tank (in front and under the battery), explaining the cruise problem and I bet your vents "shut off" while the engine is under heavy acceleration at highway speeds.

[MillenniuM]

Now the problem is that my car doesn't have that vacuum resevoir tank, i think that is why the cruise control works only sometimes.. well someday i will made this vacuum tank.

[Anonymous]

are you sure you don't have one? Its like in front of the driver's side wheel.. under the batt. Looks like a black plastic ball that is hollow (I didn't see if for the longest time and then didn't know what the heck it was!)

[robby1870]

Mine doesnt have one either, I broke it off, by accident, and the car runs flawlessly. I did have to plug the vacuum line going to the canister with a golf tee to make my cruise/HVAC work properly