Yesterday, when I got home from work, my idle started jumping from 1200 to 1400 rpm, instead of sticking at 900 like a good idle should. I took a look at the MAP sensor, and the hose was still firmly connected, but looked kinda old and worn. I tried it again today, and when the engine's cold it idles steadily at 1500, but after driving for a bit it goes back to the same old seesaw.

Since I'm a newcomer, not just to the rx7, but to anything more complicated than refilling a gas tank, I'm going to need an assload of help & tools, but I don't have the $500 for PF supercars and I'd like to participate in the process as much as I can to alleviate my lack o' knowledge & skill. I think it's still safe to drive, it seems smooth except when idling.



Help?

 

i not an expert but mine was leaking at my Y-pipe





2 xtra eyes cant hurt

 

ill help when i can



im not an expert either but it sounds like you need aa hose job bad from what you tell me

 

I'll do it for $300 when I get back from Rotor fest if you want.

 

Heh, looking at the pattern of replies--seems like you shoulda prefaced that with "I am an expert, but..."

I dunno if I'll have $300 by then--I think I'll try to get it done without, but call you in for help if it all blows up or something, take pictures throughout and put 'em up on the board to see if everything looks right, if that's ok, heh. Couple more things about it--when I turn on the headlights, even the running lights, the idle goes up to 1500 RPM and stops bouncing up and down. But if I raise it steadily with the gas pedal, even to a bit over 2000 RPM, it still does it. Could it be an electrical problem, or something else?

 

i had the same problem and it ended up being my lower intake manifold gasket.

 

Sounds like maybe a map sensor that is unpluged or possibly an engine ground.

Those are my first guesses.

As far as the vacum hose job, It is not hard you should be able to do it no problem. A bit of advice, make sure to mark every thing you take loose while getting the manifold off. If you dont know then you will have a hell of a time figuring out where everything goes when you try to reassemble it all. Use masking tape and mark things like #1hose-#1hose etc.

mark the hose or connector and the place where it will go back to. It will save you a ton of time scratching your head. Make sure to be very carefull removing the old hoses, they can get frozen into place as they are so old. Use a razor knife and slice them down the middle and twist them off. Do not tug on them or you will break a solinoid nipple, very easily i might add. The solinoids are $75 each so make sure to follow my advice or you will be spending alot of cash on new solinoids. Do one hose at a time as not to get lost or confuse yourself. Also if it seems easier to you the solinoid rack(rats nest) comes out with three screws so that you can do the job on a bench instead of leaning over the car and killing your back. And lastly watch how you run the lines, make sure that they will not be kinked or pinched by something when the manifold goes back on top of the rack, there is one that you need to tuck under the rack to keep it from pinching, you should see which one I mean as long as you pay attention to where everything will be once reassembled.

Other than that Dave Disney's site has great pics of the procedure. Goodluck

http://rx7.voodoobox.net/





-Dave

 

That engine ground thing--where could I find info on it? Still haven't started with the hoses, but the consistency with which the idle smoothes out right at 1500 RPM when I turn on the headlights makes me wonder if it's really a vacuum problem.

 

Normaly when the car idles high like yours in is pulling vacumm from some where else before the sensor in the throttle body. So the air it is getting and the air it meters are different. Mine did the same thing, mine was the throttle body was stuck open just a little. Clean it up and the problem went away. What where you working on, or did the car just start doing it on it's own? Sound like time to go no seq, but that is up to you. Problem like your are why I went single!

 

I hadn't even changed the oil yet, just drove it home from work and when the turbo timer started idling it the needle was swinging from 1200 to 1400 about twice a second. Of course, I turned the timer off immediately and it did the same thing--it's never failed to follow suit since unless the engine's cold or I have the headlights on, in which case it idles at a steady 1500 rpm.