guru20

My car will not idle. It used to idle roughly, but i started messing with the throttle position and BAC, now it won't idle at all. When i start it up, it wants to die immediately, but if i give it gas for about a minute, it will idle high on its own. After the revs start to die down it dies out. Ive spent so many hours trying to figure out what the problem is. Also, once i get up into higher revs, while im driving, it feels like the engine is skipping or something. I loose almost all power, even though the revs are still high. Any ideas? thanks

Turbonut

iTrader: (1)

Do you now have the TPS set correctly @ 1k ohms after warm up? Did you check the green Mazda checker also?

guru20

I dont have the TPS set correctly..i have a multimeter, but not the light checker. I know there are writeups on setting the TPS, but my brain is retarded. lol. thanks

guru20

ok i set it 1k...but i couldnt start cause of flooding..ill wait like an hour, Do you think it will idle?

Turbonut

iTrader: (1)

I guess we'll see. If it's a 1K the TPS should be ok, and if still a problem try disconnecting the electrical connection at the BAC valve. The green Mazda checker is just a double check. The single pin to each of the double pins. Only 1 combination should read voltage. Have you checked the BAC out for leaks/operation, or checked for any vacuum leaks?

guru20

I still doesnt idle properly...it just dies. i havent checked for leaks because im not too sure on how to go about it. Its so frustrating trying to figure out whats wrong. Thansks.

Aaron Cake

iTrader: (1)

1. If you messed with ANYTHING, it has to be set back to stock before you continue. Grab the factory service manual from http://www.f3s.org or the Haynes manual, and follow the instructions to reset everything to before you messed it up.

2. Search for "vacuum leak" and variations of that. Read, apply knowledge.

HAILERS

Download the Fuel section of the FSM.

Set the timing IF the idle is below 900 rpm. If above do not set the timing.

Set the tps. Put your meter on pin 2G of the ECU and see if it reads one volt. If not....turn the tps screw til it reads approx one volt. Note: If you want to use the green check connector to set the tps, that's fine...but the final result of setting it that way is an output of..one volt at the ECU. If you don't wanna go to the ECU to read it, then put you positive lead of your meter up the backside of the green/red wire on the tps plug and screw the tps screw until it reads one volt appros. Done.

Install the initial set coupler. Set the idle using the bac screw. If you can't get close to an idle of 750, then use the variable resistor to try to get there. Note just where the variable resistor screw was prior to messing with it so you can always return to the original setting.

If you adjusted the idle...now remove the initial set coupler and let it idle. While idling...remove the bac's connector. The idle should most likely change just a touch one way or the other. What happened?

Download the Fuel section of the FSM and read it for clues.

IF still in trouble....get a can of starter fluid and spray the intake duct and its connections. If the idle changes while doing that, then you have a leak where you were spraying. Spray the bottom of the fuel injectors for air leaks. IF the idle changes....get new bottom grommets for the fuel injectors.

Follow each plug wire and make sure the Lead wires go to the bottom plugs and the Trail wires go to their respective plugs on the top. Numbers are embossed on the coil assy for T1 and T2. Also next to each spark plug there is a L or T stamped/embossed near each plug.

Using a timing light to make sure the timing is spot on. Only if the idle is below 1000 rpm though.

Read the FSM and play with the car.

Also.......the acv has a diaphram in it that feeds air into the INTAKE at or during deceleration. No other time does it inject air into the INTAKE. SOOO....this diaphram gets old and WILL leak air when old. This is not good. The fsm shows you how to identify a leak. I do this. Take the hose off that runs b/t the airpump and acv. While the engine is running, spray starter fluid in that hose towards the acv. If the idle changes radically ...its leaking.

REad and understand the following: http://www.teamfc3s.org/info/articles/idle.html

guru20

thanks

RustX7

Make sure there aren't any acorns or other crap interfering with the moving parts on the outside of the throttle body. My idle was bouncing and after a month of messing around with the car, I found some crap holding open my secondary throttle plates. Doesn't sound like your problem, but things love to live in there so you never know.

And do all that stuff that HAILERS said to.

guru20

OK... I found a busted hose..a very small one connected to the BAC underneath it. Could this be the reason it isnt idling? Thanks

guru20

bump

RustX7

That could be it. It needs fixing anyway for you to continue your diagnosis.

I assume you're talking about an air hose (and not the thinner, longer coolant hose that runs around the BAC from under the intercooler) - is it about 4" long and goes down and to the right and connects to the pipe that goes up into the intercooler?

If so, that being just an air hose, you can replace it with a section of heater hose. Go buy 1 foot of heater hose from an auto parts store (make sure the diameter of what you're buying is close to the hose that's broken) and a couple of small hose clamps.. cut the hose to the proper length and hose-clamp that sucker on there in place of the broken one.

I might be stupid and you might be able to buy straight air hose of that diameter but I really doubt it matters for this.

Check all your hoses for cracks. My 87 TII had (and still has, sort of) a crack in the turbo inlet duct, right where it meets up with the turbo. It probably wasn't letting much air in but it escaped all my spraying with starter fluid.

HAILERS

Yeah. The air inlet hose under the bac on a turbo is a good place to find air leaks that cause havoc with the idle. Spray starter fluid at it while at idle. The idle should not change a bit if its good.

*******Check all your hoses for cracks. My 87 TII had (and still has, sort of) a crack in the turbo inlet duct, right where it meets up with the turbo. It probably wasn't letting much air in but it escaped all my spraying with starter fluid.******** Been there/done that. That leak is hard to find with starter fluid because of the location and the air from the fan blowing the fluid spray everywhere but where you want it to go. Take the duct b/t the afm and the turbo off and do a visual on the area around the clamp.

HAILERS

Yeah. The air inlet hose und

guru20

Ok..that didnt fix the problem. When i start the car it wants to die, if i apply gas for about a minute it will start to idle...and it will continue to idle for about 4 or 5 min. I was looking in the engine bay while it was idling, trying to find any cracks or air blowing, i didnt find anything. I did hear a constant wooshing of air from someone...i noticed when i had my BAC all the way out..it got worse. But when my engine stops idling..after about 5 min there is a heavy woosh that is very noticeable. Any ideas?

RustX7

Wait.. So you start it and have to give it gas to keep it going, then it'll keep going on its own but only for five minutes before it dies? And when it dies you hear a woosh?

Did you remove any of the piping to help you look for cracks, or did you just feel around? If you're not intimately familiar with the car, that might not cut it.

Have you done anything that HAILERS said to do yet?

guru20

I didnt remove any piping, i was just feeling around...i havent done anything yet...cause it was dark as hell and i couldnt see ... im doing all that stuff today. But i have to give it gas to keep going, and then it will only go for 5 min before it dies. When it dies i hear a woosh. thanks.

guru20

Ok..more input. While it was idling for that 5min..i checked the engine bay...i noticed that the wooshing was coming from the intake. I took apart the stock box and the hoses that lead to the turbo. On the hose that hooks right up to the turbo there was a crack...and it was kinda loose. I put it back on tightly...and it idled. But it will still die if i leave it idling for like 10 min. Should i try to tape up that crack? Also...now the engine wont go above 1500 RPMs it just bounces up and down right at 1500 if i apply the gas. Is my TPS screwed up? Thanks guys.

guru20

bump

RustX7

Tape up the crack, see what happens. Whatever you do though do not let any tape or anything get sucked in. That will be bad. You should get a new turbo inlet duct. Mine has the same crack and I have it taped right now. I'll be getting a new one soon. But since yours improved when you tightened it, it may get even better when you really close that crack, so try taping it first.

Then regardless of what happens, adjust your TPS anyway. It's easier to do than the damn turbo inlet duct.

guru20

I taped the TID and my car idles now! At first it idles at a solid 900...but after i drive it, it gets really low...almost to the point of stalling out; it stays though, right at that point, barely idling. Also..I cant really go past 3000 rpm in gear..It feels like its skipping or misfiring or something. Im thinking maybe fuel filter, fuel pump, injectors or spark plugs...im probably gonna change all of them, but any ideas?

$100T2

iTrader: (1)

After I read your initial post, this was the first thing I was going to tell you to check... That little crack is the source of most of your problems. The factory TID is $120 or so at your mazda dealer, or you can do the TID mod for about $10 bucks or so, plus the cost of a filter... I believe www.1300cc.com has a how-to on it... just remember for our year T2, you have to have the intake level or it will screw everything up. As soon as I changed mine, all my idle problems went away.

guru20

Yeah im thinking about building a TID tomorrow... saturday project! I cant figure out the lack of power though. Could it be an exhaust leak? I can rev the engine fine when im in neutral, but with a load it skips and stutters like crazy. So freakin annoying. thanks.

RustX7

$100T2 - what do you mean by having the intake level?

guru20 - No power is bad. Do a poor man's compression check: Take out the front rotor spark plugs and turn the engine over by hand using a ratchet and a 3/4" socket at the front pulley bolt. You should be turning the engine clockwise (as you face the car), so the ratchet should be on the "tighten" setting, though I don't think it really matters (I just don't like the idea of turning the bolt or the motor the other way.) Turn the pulley around three times, and you should hear three woosh sounds out of the plug holes. Replace the front plugs. Remove the rear plugs and do the same thing, and cross your fingers because that's the fragile rotor.

Do a search for this method and there will be a better explanation of it. If you don't get those wooshes then get a small mirror and try looking in the lower sparkplug holes to see if your apex seals look OK.

And when you go to put the plug wires back on MAKE SURE YOU REATTACH THEM TO THE PROPER PLUGS.