RE: Idle problems
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RE: Idle problems - 7/13/2007 9:46:38 AM
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cwb
Posts: 1508
Joined: 5/13/2007
From: eastern NC
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quote:
ORIGINAL: RRT vette
You can usually hear vac leaks....like a hissing sound.
That's a negatory there, rrt.
My '87 had a ton of leaks, and the only one I ever heard was the one from the incorrectly seated cold start injector, AFTER top end re-assembly.
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RE: Idle problems - 7/13/2007 7:24:56 PM
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lbelew
Posts: 54
Joined: 7/10/2007
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Thanks for all of the good info. Cleaned the throttle body and still have the idle problem. No indication of vacuum leaks using the propane method. The erratic idle only occurs after initial warmup and once again if I set my idle at 700rpm the car runs great. I think I'll check the power and burnoff relays next.
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RE: Idle problems - 7/13/2007 7:49:41 PM
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cwb
Posts: 1508
Joined: 5/13/2007
From: eastern NC
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quote:
ORIGINAL: lbelew
I currently do not have any codes stored or a service light.
I missed that you got no codes. Confirms vacuum leaks. Nothing else will cause your symptom. Nothing.
Any motor gettin' air that's not mixing with the gas (or not getting 'registered' to mix with the gas), will rev when the air mix leans out.
THEN...
The carb'ed motor pulls more gas (no throttle change), and it revs down.
The TPI revs as the leaner mix passes (no throttle change), the computer gives gas for the revs, and it slows back down - cause no acceleration.
Tunin your carb, you increase the fuel from the jets, the revs go down.
My neighbor's lawn mower did it.
Ya gotta' get a torque-on. The bolts, that is... Either that, or pull the plenum TB, runners, and intake. If you don't, you will get carbon fouling.
Gas is not what burns. It's the oxygen. Rocket fuel is liquid oxygen.
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RE: Idle problems - 7/20/2007 6:20:28 AM
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lbelew
Posts: 54
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Once again thanks for the info. Thought I had it fixed when I pulled and cleaned the Idle air control, but it started acting up again at idle. One thing to note is that my air plenum was pretty sooted up when I pulled it to clean the throttle body. I am picking up a lower and upper intake gasket set today. Any suggestions of what else to check while I have it apart. Thanks.
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RE: Idle problems - 7/20/2007 8:11:35 AM
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cwb
Posts: 1508
Joined: 5/13/2007
From: eastern NC
Status: offline
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quote:
ORIGINAL: lbelew
Once again thanks for the info. Thought I had it fixed when I pulled and cleaned the Idle air control, but it started acting up again at idle. One thing to note is that my air plenum was pretty sooted up when I pulled it to clean the throttle body. I am picking up a lower and upper intake gasket set today. Any suggestions of what else to check while I have it apart. Thanks.
Get some parts cleaner. The gallon size, with the basket in it. Get a couple of paint brushes, for paintin' on the parts cleaner. Get a low-rise plastic tub that the intake will fit in. That catches the cleaner fluid as you brush it on. Get a bottle brush for the plenum and the runners - they got a ton of carbon.
Get some Trans-X for the injectorO-rings. If they're not visibly cracked, they'll re-seat just fine if they've been allowed to sit in the Trans-X for 6 hours. AND KEEP A FINGER ON THE INJECTOR CONNECTOR CLIPS WHEN REMOVING, TO PREVENT BALLISTIC DISAPPEARANCE. Someone else called 'em Jesus clips, but don't use his name unless it's from the heart .
You might need an 8" long x 1/4" drive ratchet extension, with a 1/4" x 3/8" adapter on the end, to get the passenger side, rearmost intake runner-to-intake manifold bolt. And possibly the forward-most passenger side bolt also. THEY ARE TOUGH!
Put all bolts back in the original holes as soon as possible, until ready to clean the bolt and hole itself. Penetrating lube with the spray tube works pretty well for the hole. You do NOT want to mix up bolts. I don't think there are two alike, except the distributor cover (maybe...).
Do a total dry (trial) fit at re-assembly, without gaskets. Trust me.
Put a grease film on all gaskets when you do final re-assembly. And they gotta' be SURGICAL clean. You don't want ANY air leaks. Use metallic thread lube - can't remember the metal. Anybody?
When removing parts, make sure there's NO 'jam' in the bolt heads. YOU HAFTA make sure the socket is well seated in the bolt. Especially in the hard-to reach spots. One 'round-out' in the wrong place is gonna' triple your work time and cost.
Don't drop any bolts in the distributor hole. Make sure the cold start injector is properly seated. If you miss, it won't take long to find out what's up with that. After you get that one right too, you won't believe the difference.
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< Message edited by cwb -- 7/20/2007 8:25:24 AM >
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RE: Idle problems - 7/20/2007 11:39:08 AM
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lbelew
Posts: 54
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Thanks, Ive got a busy night ahead of me.
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RE: Idle problems - 7/20/2007 12:59:24 PM
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cwb
Posts: 1508
Joined: 5/13/2007
From: eastern NC
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quote:
ORIGINAL: lbelew
Thanks, Ive got a busy night ahead of me.
Night, huh? You probably could if ya' really wanted. But don't.
It took me 3 weekends+ ~ 55-60 hours. The dry fit, putting each bolt back in the hole as you go, cleaning out bolt holes with lube, AND A SHOP-VAC (call it over-kill if ya' want), cleaning bolt threads with a toothbrush, and stopping to take pics and write stuff down, really adds alot of time.
But afterwards, you KNOW when you pull the trigger, it's gettin' ready to play SWEET music.
Unless you didn't properly seat the cold start injector. Only took a minute to figure that out tho'... .
EDIT:
Put a piece of tape extending from the distributor rotor to the underneath outside of the rotor housing. THEN, before pulling the distributor out, cut the tape between the two. The rotor will turn as you pull it out, independantly of the shaft, and the tape will 'UN-align. It will 'RE-align', as you re-insert.
Also, mark the shaft in relation to the manifold mount hole, and score it with a screwdriver, along with the shaft. You can also put a piece of tape from the base of the rotor housing, to the firewall top. You want to have as many reference marks as possible. And remember how it turns as you pull it out, because you have to turn it back before going back in. the cam drive gears are helical.
< Message edited by cwb -- 7/20/2007 1:15:03 PM >
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Don''t know nuthin''; ain''t never got paid for wrenchin''...
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RE: Idle problems - 7/28/2007 6:41:28 AM
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lbelew
Posts: 54
Joined: 7/10/2007
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Spent a good twenty hours pulling and cleaning the intake system. Still have the same idle problems and now Ive got a little hesitation when putting the pedal down. Still no codes present. One thing to note, when the car is idling erratic and I remove a vauum hose, any vacuum hose, it smooths right out for a couple of minutes before going back to its erratic idle. Any thoughts. Thanks.
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RE: Idle problems - 7/28/2007 7:03:14 AM
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cwb
Posts: 1508
Joined: 5/13/2007
From: eastern NC
Status: offline
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quote:
ORIGINAL: lbelew
Spent a good twenty hours pulling and cleaning the intake system. Still have the same idle problems and now Ive got a little hesitation when putting the pedal down. Still no codes present. One thing to note, when the car is idling erratic and I remove a vauum hose, any vacuum hose, it smooths right out for a couple of minutes before going back to its erratic idle. Any thoughts. Thanks.
If it smooths out for a moment, that seems to mean the computer is readin' the air well (and unfortunately, the leak too).
Did you see any places during disassembly where the gaskets were compromised? Worn through? I guessin' you got a different leak now, from somethin' not seated right. ESPECIALLY if no diagnostics codes are tripped.
If you can't find it, you're gonna' have to crank the idle speed to get a steady idle speed, and hit it again with a propane torch.
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Don''t know nuthin''; ain''t never got paid for wrenchin''...
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RE: Idle problems - 7/28/2007 8:51:17 AM
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lbelew
Posts: 54
Joined: 7/10/2007
Status: offline
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Old gaskets looked to be in good shape with no areas compromised. I'll hit it with the propane again. How do I troubleshoot the computer if the whole thing has been the computer from the start. thanks.
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