phunny

I have a half bridgeport so my idle is set for around 1100-1200 rpm and it idles perfect when I start it up and even when it warms up. But after I drive any distance at all the idle stays around 1700-1800rpm. I've been researching this and really the only thing I saw was a guy that changed his throttle cable to fix the problem. But he even said that he could get his throttle to go down by "bumping" it. This is not the case for me. And I was thinking boost leak, but this would cause the high idle during any conditions. Any input would be great.

Thanks again

Charlie

It figures, right after I posted this I found a thread about a dashpot. So I'll take a look at that tonight and see if it's the cause.

1QWIK7

iTrader: (33)

Yeah theres def a leak somewhere.

When the gasket from my UIM to my TB was bad, my idle was a bit higher than usual.

You can check for leaks by spring some carb cleaner over the suspected areas. Have your car running so when you spray and you see your idle dip down, thats where the leak is.

You might need another person to assist you because when you spray and the idle dips, the car might die so you might need someone to hold steady the gas pedal.

2J-Z

Doesn't really sound like a leak, because it should happen even when u start up. Like you said, it could be the throttle cable set up.

Its could also be running a bit lean, when it warms up that could cause it to idle a bit higher, check your fuel filter etc.

twisted7

iTrader: (3)

it can be a leak, even if it doesnt do it at warmup. It could be a leak that only happens once the car warms up and things loosen up. Then once the engine is cold it closes back up. Just in the way a coolant leak might start. just do a vacuum leak test.and your problem will be solved.

phunny

Well, I can't find the dashpot so I'm assuming mine was removed. I was looking over my throttle cable today and I noticed that thing is long. It actually has a big loop before it goes onto the throttle body. What is the lenght of your cables?

Boost leak test will be done when I get the dash back in. Thinking of carbon fiber instead of paiting it. Especially since my gauges are all carbon fiber.

twisted7

iTrader: (3)

huh? Vacuum leak is done under the hood. Throttle cable is normally long, they all loop by the twins. I dont think your dashpot would have been removed? your rpms would drop instantly instead of gradually. The dashpot helps bring the rpms down slowly as to not stall the engine out.

arghx

iTrader: (3)

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/new-pfc-idle-sticking-problem-solving-strategy-isc-installed-853278/ I have covered similar problems in that thread.

There should be 1-2mm of freeplay in the throttle and cruise control cables per Mazda specs.

What is your ECU? Are you running a Power FC? If so, type in exactly what you see under the settings--> rev/idle menu.