After having a factory rebuilt motor from Mazda installed in my 85 GSL SE, I was told by the factory trained tech, that a pitted throttle body is the cause of an erratic idle which is preventing the proper completion and delivery of my car."It was determined that the pitted throttle body is causing a turbulant air & fuel mixture. It has been suggested by the tech that I seek a used throttle body or aftermarket replacment. After locating 2 ea used throttle bodies and being told that both were in worse shape than that which is giving the problem, I'm at a standstill since Mazda no longer manufactures throttle bodies for my car. Any suggestions on replacement parts will be appreciated.

 

Not wanting to question "Most knowledgeble Factory-trained Tech Guy," but I'm wondering how in the Hell do you get a "pitted" throttle-body? Isn't the Throttle-body the large intake piece with three butterfly valve air holes? Doesn't the rubber/plastic intake hose run to it from the air filter? What could be large and heavy enough to penetrate through the air filter then climb up the air hose against gravity to finally impact against the throttle body with enough force to pit it?

Furthermore, again I'm just an 'ol Cowboy with MMO for blood, but what kind of "pitting" would be serious enough to disrupt the air-flow so much to cause "erratic idle." Wherever these "pits" are they must be huge to cause such "turbulence." My SE is from Texas, and the windscreen is pretty well "pitted" by Texas sand and dirt, but it doesn't seem to affect the car's overall areodyamics....
Sounds more to me like injector problems. I'd send 'em out to be blueprinted and balanced. Had a '89 engine built, and though the new engine was fine, I had to have the injectors cleaned and balanced before it ran properly....My present SE has over 180,000 on it, and if anything was to become "pitted" my engine would certainly be so...But strangely enough....runs like like a teflon bullet....

....But Shoot, Son...I'm just an 'ol Cowboy with grease under his nails, and oil on his Stetson. I tend to ask too many questions, and tend more towards logic than speculation and magic....

Denny, from the "ol corncrib....

 

Danny, my SE had been sitting up for several years before taking it to get the engine replaced. Old fuel had varnished, the fuel tank had rusted and was replaced, fuel lines flushed, and also the air meter was replaced with used parts. I don't know if all this contributed to the "pitting" or not, but the bottom line is that I want my baby to run like that teflon bullet you talk about. I've spent more than what planned already and the thing still don't run right. I havn't taken delivery on the repairs as of yet. This factory trained Tech Guy, has said that the dealership will work along with me to get the car running right, but I will have to supply the parts. What do you think about replacing the intake with performance parts? Any suggestions? I'm basically stuck with this Factory Tech Guy because I know of no other who can get my baby to purr. I live in the Tidewater Virginia area.

 

Tony...
I'd give you my engine builder's phone number, but he operates out of Newark, Ohio....I suggest that you give fellow forum Cowboy Pele a private message. I know he lives in Virginia....Also get a message to Max7....He supplies web room for our sticky pix section....

Denny, from the 'ol corncrib....

 

I'm nowhere near Hampton... Although, Peter Farrel is up near here. Dunno if he does 1st gen work though

Gonna be up north any time soon Tony? I could take a look.

 

Can't you just port it a little and polish the pits out?

 

I think the dealership is full of ****.

How do you get a pitted throttle body and still have a good engine?

How does pitting ruin the air flow?

How is the air still excessively turbulent after is has flowed from the throttle body down the upper and lower intake?

That factory trained tech might be highly familiar with a Miata, but probably has never seen a rotary.

I'd take the car from them and check for vacuum leaks. It's probably the shutter valve.

 

A shutter valve on a GSL-SE? Maybe thats why it won't run right, it has the wrong **** on it

 

Damnit! I shouldn't post this early in the morning. But seeing as I slept in till the afternoon, I should just not port till I've woken up...