Help! Throttle Body Clean/Swap

[Randys88Vette]

Hey Everyone!! Had a tuneup done on my 88 and it was suggested I clean the Throttle body or replace it. In discussing it with the mechanic, he said it is fairly simple (and cheaper) to clean it myself but that I need to 'reprogram the ECM" after i do it, otherwise, it will never find idle. He said they could do it at the shop for $400 but I told him I'd do it later on. He said the same holds true if I just buy a new TB and repalce it.

Does anyone know what he is talking about or where I can find a procedure to do this? I am pretty mechanically inclined and all, but as this is my first Vette, I am unsure on how some things need to be done. Any help from anyone would be appreciated.
Thanks!!

 

[badglas]

Dirty Throttle body

There is no reason to replace a throttle body because it is dirty. Reprogrammig an 88 ECM after cleaning?? You may need to re-learn the idle, but that is a simple procedure. There are 2 ways to clean the throttle body. 1 is a simple cleaning, the other is extensive. Based on what to have posted, start with the simple.

Get a can of air intake/throttle-body, it will be an aerosol, and a couple of clean shop towels. Take the air intake snorkel loose at the throttle-body, release the mass air flow sensor from the air cleaner housing, unplug the sensor and set these pieces aside. Spray some cleaner on one corner of one of the towels. While holding the throttle open, clean the the throttle blades, as well as the throttle-body housing. Repeat this process until you have removed all, or most of the coking. DO NOT SPRAY CLEANER DIRECTLY INTO THROTTLE_BODY! Reassemble the removed parts. Disconnect the battery for 5 minutes. Connect the battery, start the car, and go for a neighborhood drive. (constant starts and stops with lots of idling in gear)

If this does not cure the problem, post again, or e-mail me and I will outline the extensive cleaning, and how to set minimum authority for a complete idle relearn.

Most honest shops would charge 1 hour for the light cleaning, 2 for the extensive plus parts, ($25-$30). I charge $90 per flat rate hour. Unless The throttle shaft or bushings are worn out, there is no reason to replace the throttle-body.

Ron Kane
Benchmark Corvette Service

 

[Towu4free]

There is no reason to replace a throttle body because it is dirty. Reprogrammig an 88 ECM after cleaning?? You may need to re-learn the idle, but that is a simple procedure. There are 2 ways to clean the throttle body. 1 is a simple cleaning, the other is extensive. Based on what to have posted, start with the simple.

Get a can of air intake/throttle-body, it will be an aerosol, and a couple of clean shop towels. Take the air intake snorkel loose at the throttle-body, release the mass air flow sensor from the air cleaner housing, unplug the sensor and set these pieces aside. Spray some cleaner on one corner of one of the towels. While holding the throttle open, clean the the throttle blades, as well as the throttle-body housing. Repeat this process until you have removed all, or most of the coking. DO NOT SPRAY CLEANER DIRECTLY INTO THROTTLE_BODY! Reassemble the removed parts. Disconnect the battery for 5 minutes. Connect the battery, start the car, and go for a neighborhood drive. (constant starts and stops with lots of idling in gear)

If this does not cure the problem, post again, or e-mail me and I will outline the extensive cleaning, and how to set minimum authority for a complete idle relearn.

Most honest shops would charge 1 hour for the light cleaning, 2 for the extensive plus parts, ($25-$30). I charge $90 per flat rate hour. Unless The throttle shaft or bushings are worn out, there is no reason to replace the throttle-body.

Ron Kane
Benchmark Corvette Service

I agree with this guy, $400 to replace WOW!!! and i have never heard of having to correct the computer, with the Idle air control valve it should learn itself from the PROM in the cpu

 

[Randys88Vette]

The service tech told me that the TB had some bad carbon deposits and probably had some in its small passages inside. He suggested I take it off and clean it out completely. Or I could just buy a new one. Then I would have to get the ECU to understand the "new" idle point. He said something about disconnecting the idle control and something else, turn the key to on, then off, reconnect it, then something else. He said I needed to do it 2 times to get it to recognize the cleaned/new TB idle point.

I will try the simple method of just wiping and cleaning and see what happens. I dont think its that bad, but apparently they think it is.

I'll let you know what happens. Thanks.

 

[aklim]

I have been taught by someone and have used a scanner since to adjust my min air idle. I get the thing cleaned and reassemble. Get the car hot and into closed loop. Adjust the TB screw for the blades till I see about 20 IAC counts, reset the TPS and I'm good to go.

 

[Randys88Vette]

Finally got it done!!

Well, i must say thanks to all. I finally had some time to work on the car this weekend and got the TB cleaned and the open air filter lid and K&N air filter installed. Now I must say...WHOA!! What a huge difference it makes!! With the open filter breathing more air and the TB being cleaned, my baby is back to laying tracks form a dead stop!! And chirping tires when i floor it at! Tranny shifts much better and harder and isnt starving for air!

I thought i would just take it off and clean it, so I got gaskets for it and some carb cleaner. I also took a used greenie scrubbing pad and soaked it with the carb cleaner and cleaned th front side. Couldnt get the back to clean , so i unbolted it, disconnected everything except the hose that has coolant in it (on the bottom) , held it away from the plenum and was able to clean it up nicely! It shines! Made sure there were no minute scratches in it by using my magnifying glass and xenon penlight. Looks sparklign new. Bolted it back on along with everything else,started it up and did the littel stop and go , key on, key off thing, and the idle came right back to 800. Quicker response off throttle too. Then, put the open filter on and WHOA.... HORSEPOWER!! Took it for a test drive and I was smokin' and chirpin' tires!! Totally awesome! Found a procedure to check the voltage and such now as well adn will do that next.

Knew I could count on fellow Vette friends to help me out!!


A big thanks to all !!

 

[Schrade]

Hey Everyone!! Had a tuneup done on my 88 and it was suggested I clean the Throttle body or replace it. In discussing it with the mechanic, he said it is fairly simple (and cheaper) to clean it myself but that I need to 'reprogram the ECM" after i do it, otherwise, it will never find idle. He said they could do it at the shop for $400

Does anyone know what he is talking about or where I can find a procedure to do this? I am pretty mechanically inclined and all, but as this is my first Vette, I am unsure on how some things need to be done. Any help from anyone would be appreciated.
Thanks!!

He's talking about a fishing expedition that he wants you to fund yup :eyerole.

Tell him if you see him again to briefly detail this procedure, and post this $400 procedure on the internet, along with his business number.

He will opt to keep his fertilizer in his own garden, I bet. :eyerole

If the battery is NOT disconnected before the TPS is disconnected, the ECM will re-calibrate the 'normal' position after half a dozen drive cycles. In the meantime, it will take an automatic tranny a little higher rpms in each gear, nothing more.

If you disconnect the battery first, you don't need to do anything.