I am going to be putting a kit and remaned injectors in my throttle bodies in a week or so.

I really want to pull both bodies from the plate and replace those gaskets. My fear is when I separate the bodies from the plate, they will lose synchronization. I don’t want to have to start drilling and filing welds. The car is running okay now, it just stumbles a little.

If I pull the entire top plate, put the plate with bodies on my workbench, then, without disturbing the connecting linkage or fuel line, I slightly lift each body and replace the gasket, will the dowels inserted in the plate kept the synchronization?

Or, once the bolts have been loosened, the bodies shift enough to throw it off?

Advice from someone who has done this before, please.

 

Not sure what you mean by synchronization? The injector pulse is controlled by the ecm. Rebuilding the throttle body won't affect that.

 

Throttle plate sync....L and R throttle body...like a bike.

Jebby

 

So unless he touches the throttle linkage, he shouldn't have an issue.

 

Not true.....each throttle body can move slightly when removed and re-installed. It is important that both blades are shut at idle completely.....

Jebby

 

i don't think eyeballing them to open together is rocket science. and it is really most important in the first little bit of travel.

 

Any second now BUCCY IS GOING TO CHIME IN! LOL.........tick tick.

 

Thanks for the responses.
I have read how to synchronize and I am sure I I could do it given time, but just really don’t have the time right now. I think one of my injectors is spraying a messy pattern, so I want to change them both. However, I would rather not get into the entire balancing act.

For now, I will just rebuild the TB’s while they are attached to the top plate and just check the torque on the TB bolts. Maybe the injectors with new accumulator-regulators will fix my little stumble. Got a new fuel filter in now and will also check my fuel pressure while I am at it.

She’s running pretty damn close to perfect right now, so I will keep my carport tinkering to a minimum.

 

Last weekend I rebuilt my T/Bs without removing them. The T/Bs-to-intake manifold gaskets are the only gaskets that remain original, but tight/non-leaking. It was all pretty straightforward, though not without requiring full concentration. Here were a few of my observations:

The crossover fuel line between the T/Bs was a bit** to remove from the rear (driver side) T/B because it is under a lip, until I bought a crowsfoot (brake lune) wrench as someone here had recommended. My stubbornness to stop and go buy the proper 5/8 wrench caused me to twist the fuel line, and had to order a new one. PM me if the same happens to you, and where I ordered it from.
. Keep firm thumb pressure on the fuel regulator and compensator barrel covers when removing them as they are under a little bit of pressure and you want to see exactly how the diaphragm plates are positioned soas to duplicate their positioning. The diaphragm plates are different between the two barrels.
. Apply a thin layer of gasket-compound on each of the several gaskets. I needed a razor blade to clean off the old gaskets.
. Replace the two rubber bullet plugs. My Holley ket came with them.
. I noticed that the spray pattern of the new A/C Delco fuel injectors is wider and tighter than the originals which were running perfectly fine at 45,000 miles and I often used good fuel injector cleaner. So, mine were either degraded or the new ones (unique part # for front and rear injectors) have improved the atomization dispersal pattern. I do not necessarily notice a difference in drivability characteristics or performance but it looks better - and, now idles smoother.
. After I put everything together I noticed a slight hesitation in tip-in throttle response when I first drove it, and it was idling way too high. I discovered two issues:
1.) both of my newer idle speed control motors somehow became loose (less than 1/4 turn) during the procedures which was causing a slight vacuum leak. The leak was minuscule which underscored how unforgiving our crossfires are with vacuum leaks.
2.) I had to readjust my newer throttle position sensor. It seemed fully torqued and tight, but when I adjusted it the tip-in hesitation was gone. I had lubed all of the linkages, or perhaps something in the regulator/compensator system had to reseat or whatever, but it is really running great again -just as it was before I rebuilt and sprayed cleaner throughout the T/B's, although, it has never idled this nice and smooth, as now. That alone was worth the 3-4 hr. investment (including cross-town reluctant wrench-fetching).

Good luck and hope this helps someone else to approach it confidently.

 

While you have the throttle bodies off remove the intake top and reseal it. Have yet to see one that was not leaking to some degree. Pull the throttle bodies off the intake just leave the linkage intact. Check the throttle shafts for excessive wear, you may need to have them repaired. You'll have to reset the base idle and TPS when you get it back together. Vacuum leaks, exhaust leaks and low fuel pressure are the root of most CFI issues.

 

one correction because a similar post sent me on a wild goose chase. There is no such thing or option for “base idle setting”. The IAC motor and ECM control 100% of the idle function. I just double checked the ‘82 shop manusl.

 

Here read this article it explains it in detail

http://www.superchevy.com/how-to/468...-system-tuning

 

False statement. You may need to re-read that manual or get a correct one.

 

Your interesting article reinforces my point, though thanks for sharing it. If you hold "control-F" you will see that there are (6) references to "idle". There are ZERO options for manually setting the idle. You have an `82 and should know this if you have ever rebuilt your T/B's. Your article specifically says `don't be alarmed if the idle is off, the ECM will relearn the proper idle RPM" which is consistent with the official GM, 1982 Corvette Shop Manual. Your article is correct. Your interpretation respectfully needs to be revisited. I just went through it. There is no, nada, zero option for manual idle adjustment. The idle logic is 100%, entirely between the IAC motors and the ECM which adjusts the injector pulses accordingly.
Btw, you also falsely mention that most CFI issues are related to vacuum (and, "exhaust"?) leaks and such. I agree they are a huge issue from experience (tightening intake manifold was a major improvement). But, my `82's drivability irregularities were equally related to the need to replace the several stock/original ECM input sensors, starting with the O2, and ECT (engine coolant temp.) sensors, followed by IAC's, TPS, MAP replacements (and, coil/ignition module) which collectively made my crossfire seem to run start and run like a new `82.
Stick by your story, but, unfortunately you won't find an idle adjustment on your `82 no matter how hard you look or hope for it, sir.

 

You must have skipped over "setting the engine speed to 475 rpm in drive, and setting the TPS," sometimes when the IAC reset you will have a high RPM Idle. Sometimes 1500 rpm or more. A search of the forum will show you how often that happens. That is what the `don't be alarmed if the idle is off, the ECM will relearn the proper idle RPM" is in reference to. When it happens you drive the car over 30 mph for a few minutes and the IAC reset. Sometimes you can just re-park the IAC and they will reset. Sounds like you just replaced parts until yours ran right. I guess your just another parts installer trying to act big to someone who builds corvettes for a living. Maybe your just a democrat, don't know what the truth is when you see it in black and white. Wait You work for FORD.....no wonder

 

exactly - you let the IAC and ECM do their thing. You are entirely hands off. You have zero role in adjusting “baseline idle”. You are entirely reliant on the system to properly idle. There are no manual idle adjustments whatsoever.
go trump 2020 (seriously).

 

 

How much play, if any should be in the air flap shafts?

 

LOL! Buc, you're the best.
By chance, I was too close to it. When my idle jumped up to 1000 RPM after rebuilding my T/B's, including new Delco injectors last weekend (a surprisingly satisfying and worthwhile `82 maintenance exercise), before finding out that my (2) screw-in IAC's had without my knowledge loosened in the process, I was hoping upon hope that there was an idle set-screw or some hack to manually "adjust base idle". But, based on another long-ago mis-informed legacy forum poster's reference to `properly adjusting the [Crossfire's] idle', and maybe reinforced by the forum's distinguished senator ("Gunfighter") from Texas whose admirable, but heavily modified Crossfire's updates/upgrades have significantly changed from stock - there was no such luck in finding a manual adjustment. Very misleading to someone with an original Crossfire with an idle issue as it's idle performance is 100%, entirely unrelated to it's carbureted or heavily modified CFI brethren. The `82 shop manual explains that it relies entirely on it's - then breakthrough technology - "command control" IAC-ECM electronics. Certain, well documented (on this forum/stickies) things may inhibit the readings (mostly vacuum leaks as I learned with the loose IACs and mis-adjusted TPS which were my fault), but, manual/human "baseline" adjustments of any kind whatsoever are non-existent with our magnificent `82/`84 Crossfire engines. A very high percentage of our pre-`82 Forum brethren poster's insights are extremely helpful/often interchangeable as there are basically more similarities than differences (per C3 parts catalogs) from the `68, and especially 69-82 cars - but, when discussing an entirely original `82''s unique fuelie technology (and integrated `new' O/D transmission) there are major differences to consider relative to drivability and maintenance... such as traditional `baseline' idle "adjustments" that have mostly been replaced by a, then breakthrough, advanced onboard ECM computer.

 

I also have an unmolested CFI system as stock as the day it was built. After reading my shop manual, I was having confusion about the discussion on setting the idle. Thank you for the clarification. I don’t intend to do anything to the linkage as I plan to remove the entire top plate, leave the TB’s in place, and reinstall with a new plate gasket.

With the kit, I will be installing remanufactured injectors from a company recommended on this forum plus brand new AC Delco IAC’s when I do this maintenance. I hope to leave the TPS alone.

I expect I will get a high idle for a period until I drive over 30 mph for a few miles?