A problem developing?

[Guest wally888]

Tis time to attend to several minor problems that have developed this past year.

I have a very slight rough idle. Not as rough as a complete mis-fire of a plug but enough to feel. I have peered under the hood in complete darkness, no sign of spark jump. Thought I would 1st. clean throttle body and IAC. I have searched here for IAC and Throttle Body to no avail re. what to use? Seems I read in a past post not to use Carb. Cleaner , to use Throttle Body cleaner while engine running? Hope I didn't make that up? Perhaps I should use Techtron in gas tank 1st however did that, less than 10k since ?

What could be the other causes of slight rough idle?

[Roadster90]

Wally,

Ditto on the slight rough idle....

I am experienceing probably the same symptoms. At idle/stop lights it seems the engine just misses a heartbeat intermittantly. The miss is definitely felt and is noticable as a slight drop on the tach as well. Last year I replaced darn near EVERYthing for another problem??????????

Lets hope someone can assist both of us......

[Guest wally888]

Previous years may be different, mine a 91, however, I removed IAC and it was a [censored]!

There is no room for anything other than an offset screwdriver. The heads of screws are combo but x point is marginal, common works best. My screws were coated w/ lock tight or?, was orange and very tight all the way out. Could muster less than 1/8 turn at a time. Took over 30 minutes.

The pintel was very dirty, cleaned w/ throttle body cleaner and lightly w/ fine steel wool.

Be sure to put cloth or something underneath as I dropped one screw twice while reinstalling.

I used a gun bore brush to clean screw threads, oiled, used cue tip shaft to place a little oil in holes( also to align holes) and at the moment they are in 2 threads. (taking a break). Starting w/ 2nd thread I have to use offset-still tight going back in, not , nor were they previously crossthreaded.

Will report on idle improvement.

Wish someone would comment on spraying throttle body cleaner through body w/ engine running? I once did w/ previous 89 but would like advice?

[Roadster90]

Wally,

Bore brush <img src="http://www.aaca.org/ubbthreads/images/graemlins/smile.gif" alt="" /> great idea, suggestion !

[Guest EDBS0]

<span style="font-weight: bold"> <span style="font-style: italic">I have no personal experience with this product! $3.18 from GM Direct.</span> </span>

Culled from another posting ...

"Carbon buildup can hurt performance, from the knock retard it can induce to the restriction in airflow and improper valve sealing in the combustion chamber. It is a good idea to go through this process as part of your tune up procedure.

Buy a can for top engine cleaner from your GM DEALER (other decarbon

fluids dont work as good). You want the liquid, not the spray. This is to be done outdoors ( a lot of smoke will occure). Part # should be 1050002

1.Start motor and let it reach normal operating temp.

2.Find a vaccum hose which has vaccum at all times (with engine running)

3.Open can

4.Stick vaccum hose in top engine cleaner

5.Hold the idle up as the car will try to stall

6.Let the car suck the fluid into the engine

7.Dont let the vaccum hose come out of the fluid,as if it does NO DECARBONIZING WILL OCCURE

8.Let about 90% of the can go into the car and then let it stall

9.Reconnect vaccum hose to vehicle.

10.let it sit for 10 minutes

11.Start car, car will smoke a lot

12.Drive around till smoke discontinues (better to try and use 30%, then 40% and then 50% and all the way up to 100% throttle)(meaning that you dont use one set gas pedal pressure)

I loved it."

<span style="font-style: italic">Dissenting opinion.</span>

"No, You suck the [censored] in the engine via a small vac line you pull off the car. You only suck in like 2/3 of it slowly, then you suck the rest in by sticking the tube in all the way stalling the car out. You then let it sit for like 30~45 minutes then start the car up (with ur vac line put back on) and it'll sputter out crud for like 15 minutes and you may need to rev the motor to keep it going. I advise changing the oil afterwards, and I fouled a plug doing it too, so if ur plugs are old they may go too."

I have wanted to try this on my cars. Could it be part of the solution to smoothening out the idle?

Just a thought, I have no personal experience. <span style="font-style: italic">Others???</span>

[Guest Buick Mike]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">

Wish someone would comment on spraying throttle body cleaner through body w/ engine running? I once did w/ previous 89 but would like advice? </div></div>

I have not done this on the Reatta, but did so several times on my old Taurus SHO with no problem. In fact, don't the directions on the can tell you to have the car running?... maybe, not... I can't remember.

Mike

[Guest tempest68]

I've used some brand other than the GM stuff EDB.. listed above on my '92 S-10. Definitely need to do outside, and it did seem to improve idle somewhat. (Taking off the top part of the plenum[spelling?] and manually cleaning the inside helped too, but the Vortec 4.3 Central Port Injected is a different animal.)

I've also used the intake cleaner sprays. They do okay, especially at cleaning any buildup around throttle plates. For any car, if the throttle plate sticks even just alittle bit it can affect how the engine runs at idle. When using, the engine should be running and you'll want to manually work the throttle to keep the engine from stalling.

[Guest wally888]

The screws were easier to reinstall, neither loose enough for fingers but easier. One was quite tight the last 3 threads.

Don't attempt on 91 unless you have both x point and common offset screwdrivers or..stubby too long.

I sprayed throttle body cleaner, Gunk, for 4 ten second intervals alternating throttle settings and periods of no spray. The body and butterfly were clean before I started.

Now idles very smooth!

[Guest EDBS0]

Wally;

Good news.

With long fingers or a shop rag soaked in cleaner and wraped around a screwdriver try and clean the back side of the throttle plate.

[Guest wally888]

How do I get long fingers? Have seen some of those ads but they don't mention fingers!

[Guest]

If you have long fingers, you have no need for the other ads. <img src="http://www.aaca.org/ubbthreads/images/graemlins/grin.gif" alt="" />

curt

[Reatta_Cruzin]

I've used a old tooth brush to clean in throttle-- works great, don't have to worry about rag comming off screwdriver and gouging housing, valve, etc. <img src="http://www.aaca.org/ubbthreads/images/graemlins/grin.gif" alt="" />

[poncho]

When I first picked up my Reatta last summer, it ran really rough when accelerating and a little bit at idle, too. Took it to a friend's house to show the new car to his Dad. I told him it ran a little rough. Now, this was about 8pm in late summer, it was pretty dark out and this guy lives out in the woods. So, he tells me to lift the hood and start the car. We turned off the outdoor garage lights and the yard lights. What I saw was unreal. My plug wires were arcing from the coil to the block, from the wires to the brackets and the head, there were sparks flying EVERYWHERE, up and down EVERY plug wire. It looked like the friggin fourth of July! I promptly replaced the wires and have had no further problems. So, before you start thinking that it's something insanely complicated and that it must be the computer or the sensors just because the car has 'em, try the simple stuff first. There's basically only three areas to diagnose before getting into the computer aspect of an engine: AIR, FUEL, and SPARK. If you can identify which area is causing problems, then at least you're going down the right road to solving your problem.

Sorry, I'll get off the soap box now. <img src="http://www.aaca.org/ubbthreads/images/graemlins/grin.gif" alt="" />

[PAT 90 CONVERTIBLE]

HAD THE SAME PROBLEM AS PONCHO LAST JULY AFTER PURCHASING MY 90 CONVERTIBLE HAD JUST BROUGHT IT HOME FROM DEALER AND HAD 16,750 MILES ON THE CAR.SITTING IN MY DRIVEWAY RUNNING WAITING FOR THE WIFE TO COME OUT TO LOOK AT IT. IT STARTED RUNNING ROUGH AND DIDNT WANT TO IDLE.LIFTED THE HOOD AND THE SPARKS WERE JUMPING.TOOK IT BACK TO THE BUICK DEALER WHERE I BOUGHT IT AND LEFT IT OVER NIGHT THEY ENDED UP REPLACING THE SPARK PLUGS AND THE WIRES AND IT RUNS GREAT..PAT