Ok, so I've got an 88 vert that idles really low. It'll do one of two different things, it'll either idle around 400-500 and bounce or it'll rev up to 1200 and sit there for a few minutes and then drop down and bounce.

I assumed it was probably a vacuum leak, but I can't seem to find it. But the weird part is that it doesn't do it from a cold start. If I start the car after letting it sit for a few hours it'll start up and idle perfectly around 800rpm. It'll be fine until it warms up and then the problems start.

I'm stumped. Thanks for the help.

 

Im new to FC's....I have the SAME EXACT problem!!! someone help us out!!..

 

stupid computer, sorry for the double post

 

First thing, make sure your tps reads 1k ohms at idle, and 4k-6k ohms at WOT.
Could aslo be a vaccum leak like you said. Could also be a dirty throttle body. It could be a number of different things, a little more input from more experience rotary nuts will help this guy

 

Im waiting on the "use the search button " line........

 

Believe me I've searched. I registered for the board in Sept. but haven't posted till now. Anyway, my problem just seems kinda specific. The idle is great for a few minutes (Basically until it reaches operating temp) then it gets bad. And it's not ever really all that bad. It's just really low, rough, and rich.

 

Jesus, you guys have more problems N/A than I do Supercharged Idle Wise! LOL!

Yeah, like everyone's said, check TPS, make sure there are no vacuum leaks (big * here), and while it's surging spray carb cleaner around the engine bay (make sure to have a hose ready to spray it off the engine) to check for leaks vacuum wise.

 

well i have a similar problem with my 88 S4 N/A. it will run fine until she warms up then she will die for not reason and not start. it will start after a few hours of sitting i also have the fuel pump switch so i know im not flooding it.

this a rebuilt motor i just bought and put in:
plates were lapped, rotor housings were lapped and chrome was touched up to ensure good flat sealing surface.

2mm 2 piece Mazda Apex seals and springs
2mm Mazda corner seals and springs
Viton Oil control inserts and dowel pin O rings
Mazda inner and outer water seals

Mild primary porting, big secondary ports and massive auxilary ports

im new to working on rotaries so i brought it to an expert turns out i have a huge leak in my intake gasket he said i should replace the old 6 ports, and i might need a new starter.. is this true? and suggestions or thoughts?

ive dumped a good load of cash trying to get the thing running and such im just getin really tired of small **** coming up and i want to get the thing drivable.

 

Before you go spending a bunch of money, (HA, we all know how easy that is on our cars) if you guys have access to a properly working throttle body, try swapping that in for the one you have on now and see if it cures the problem. I remember reading about someone who had an identical problem and what happened was the throttle body was randomly sucking in unwanted air through the back. He strapped on a used one and everything was dandy. It's worth a shot.