grady95

As I get through the systems on my rolling restoration, the help of the members of this board has proven very valuable. I hope my Mazda Brothers can come through on this one because this is a tough problem to solve on my own.

The car starts well and goes through warm up normally. The warm resting idle settles at 1500 RPM and will not kick down below no matter how warm the engine. Specs call for an 800 RPM idle. The FSM indicates that 800 is the normal idle. I can't get this car there yet.

The FSM shows how to set the idle quite clearly and I have followed it to the letter by disconnecting a couple lines near the oil dipstick, opening the fuel cap 's and working with the idle speed screw on top of the manifold. Easy enough! Currently, as set by the PO, the idle screw is turned all the way in clockwise, ie, it's buried. Turning it out counter-clockwise produces the following result. The idle does not reduce but the idle begins to osscilate or pulsate. This only stops when the screw is again turned to it terminal position; fully pegged clockwise. I have read the words "pulsation damper" and it looks like this is on the fuel rail. Would there be some adjustment to this that would take away the yoyo idle? Are there any tricks or hints anyone has to get this down and consistent at 800 RPM?

Rx-7Doctor

iTrader: (13)

It would take too long to explain the whole procedure. However it has been archived and I believe it is even in the FAQ's. I recommend that you print it out because it takes a bit of work. Not too complicated just a bunch of different things to do. Welcome to the wonderful world of the quirky Se injection system.

JKM

Check your throttle cable. When I first got my car it was idling at about 1500, and otherwise ran quite well. Then I noticed that if I slowly let off the clutch without using the gas, the car would still pull forward, like I was giving it some gas (instead of stalling out, like it should.) I check the cable and the way it was kinds of stuck a little, so to the car it was like I was always pushing the throttle down ever so slightly. Played with it a little, and the idle went to normal without adjusting anything else.

It's a long shot, but it's worth checking.

Rx-7Doctor

iTrader: (13)

I hope that is all he has to go thru, that would be great. But then again I want another member to feel the joy of having to go thru the whole procedure. lol.

grady95

All suggestions welcome! I noticed there are several spots in the linkage which rub or pass over each other as the throttle is applied. I did give these articulating areas a good application of Mystey Oil to be sure the issue was not simply due to metal on metal dragging. Maybe with some luck, that has penetrated by today and the problem will be solved. I expect it will help but there is probably going to be this and more. I did act on your suggestion. Let's hope it settles the issue. Thanks for your help.

grady95

I'll find the archive and take your suggestion to print it out. Really, there is no better way to truly know your car than to patiently work through these problems. I actually welcome them! Doc, I still don't have a clue on the defroster issue. Any suggestions?

rookie117

iTrader: (1)

ive had that problem once before. Check all vaccum lines and connectors. Mine was a vaccum line that i forgot to connect on the bottom of the ACV module. i plugged it up and bam, went back to idleing around 800. its a very touchy system but you will get used to it once you learn it. it might be your best bet to take off the whole intake and check everyting under in, and just make sure everything is how it should be.

grady95

You anticipated my weekend project. Good suggestion. I intend to do just that; take the whole intake off, give it all a good douche, and put it back together according to the FSM diagrams. This car has been out of commission for such a long time that really anything is possible. Believe me though, I read these posts and go right out to the garage and check each one. I will get back to you about this. Thanks