I've just finished assembling my motor from intake up (new gask. vac. lines etc)
Bad idle. Real low like 500rpm. It sat all winter, smells rich.
I'm reading 12V at the relief selonoid valve @ the ecu (pin 2P) with the ignition on but not running, it is supposed to be less than 2V according to FSM.

Could it be stuck open in "relief mode" not allowing air to the main cat or exhaust port?


Thank-you
Joe

 

bump

 

It will probably not drop to less than 2vdc until the water temperature in the radiator rises above a certain point. You'll reach that point when pin 1H reads less than 1.5vdc. Make sure the water temp switch at the bottom left of the radiator is connected OR you can connect the two bullet connectors together to get that result without heating the water in the radiator.

Until you see below 2.0vdc on 2P, the air from the airpump will not go to the exaust ports but be dumped overboard thru that one inch black hose on the bottom of the acv.

On the whole the acv and airpump cannot cause a car/engine to run bad. The acv only should input air into the INTAKE manifold during deceleration.

 

I was thinking if it weren't pumping air into the cat when it should be, the cat could be clogging up, causing my low idle, rough, rich condition.

FSM says it should show below 2V with only ignition (car off), and below 2V at idle.
Why do you think it's contingent on another temp sensor?

From what I can peice together, below 3750rpm (<2V @ ecu pin 2P) the relief valve sends air to exhaust port and/or main cat, and above 3750 rpm (>2V @ ecu pin 2P, or the 12V I'm seeing) the relief valve dumps air pump air out the silencer.

Unless the ECU "thinks" it's above 3750rpm and is telling the relief valve to dump.

 

*********Why do you think it's contingent on another temp sensor?**********

Because the purpose of the water temp switch in the bottom of the radiator is part of the control of the RELIEF solenoid. I've messed with this item (both items) in the past and THINK (which does not mean it is so) I know how they relate to each other.

When the water temp switch is cold its contacts are open resulting in approx 12v at 1H. When the water gets warm the switch closes and puts a ground on the water temp switch dropping 1H down to less than 1.5 vdc. When that happens you'll find that the Relief solenoid will now get energized (ECU at work) and cause a vacuum on the relief diaphram in the acv to keep air from dumping overboard. Now it will go to the EXAUST PORTS.
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The key your looking for is that the FSM states the engine should be fully up to temperature when you do the measurements.

If you find me wrong, I'll go out to my car in the morning and find out where I went wrong.

********From what I can peice together, below 3750rpm (<2V @ ecu pin 2P) the relief valve sends air to exhaust port and/or main cat, and above 3750 rpm (>2V @ ecu pin 2P, or the 12V I'm seeing) the relief valve dumps air pump air out the silencer.
*************

That's right, it's just that there is a bit more to it than that. Such as the temp sensor under the passenger seat that has an effect if the temp is sensed as being too hot. If that sensor gets too hot it also dumps air into the silencer in the fender (memory).

EDIT: Warm up the engine fully and you should get the right results. If you don't, make sure the switch at the bottom of the radiator is fully connected and the wiring is good from the ground and to the ECU.

 

Low and rough idle........Two things come to mind. First that the BAC is not functional. Second is that it is possible that the acv is partly responsible.

There is a passage in the acv, that goes to the intake. It should not put air into the intake unless the car is decelerating. These valves get old and leak air somethimes.

This problem can be overcome though , by removing the acv and putting some black RTV in the two holes for the ANTI AFTERBURN VALVE (an internal part of the acv). This will have no bad results. It will assure you that no air from the airpump is getting into your intake manifold at idle. It takes about forty five minutes to remove the acv, put the rtv in the holes, and reinstall the thing. Let the RTV dry for a couple of hours. I've posted pictures of these two holes in the past.

About the bac. If you have a warm car, remove the bac but leave the plug on it. You should see/feel the bac's diaphram vibrating when you touch it. Key to ON when you do that. Another thing you might do is watch the bac's diaphram when you hold the key to START (small wire off the starter solenoid when you do this). The bac should go wide open when the key is held to start. I did this test once and it worked for me. The manual says the bac should go FULL OPEN during starting. Mine did.

If the bac does not vibrate with the key to ON, I'd say the transistor in the ECU for the bac is kaput.

Back to the acv and rough idle. Try this. Get a can of starter fluid. Warm the engine up. PUll the one inch dia hose that feeds the airpump, off the airfilter. Spray fluid into that hose. If the idle changes, then the acv has a leaking diaphram into the intake manifold. It should not leak air into the intake manifold. Do the RTV job described above. Or buy a new acv for $$$$$

 

The last post by me was considering that you had already set the timing with a timing light and had installed the initial set coupler and tried to set the idle using the screw on the dynamic chamber (non turbo car, right? 86-87???).

Also adjusting the variable resistor in the R direction will make a RX-7 idle better.....usually. Always follow the fsm instructions for setting the idle/timing/variable resistor.

 

it's a turbo, thanks for the help, not done reading yet

 

now it won't start and I can smell gas. smoke break.
charging low battery

 

Pull the fuel pumps electrical plug off and crank it til it starts...then dies. Then put the plug back on and start the car. I'd make a fuel pump cut switch. Just go to SEARCH and do a in depth search using NZCONVERTIBLE in one block of the search and FUEL CUT SWITCH in the other block of the search. It will come in useful in the furture (the switch, not NZCONVERTIBLE).

 

Pull the fuel pumps electrical plug off and crank it til it starts...then dies. Then put the plug back on and start the car. I'd make a fuel pump cut switch. Just go to SEARCH and do a in depth search using NZCONVERTIBLE in one block of the search and FUEL CUT SWITCH in the other block of the search. It will come in useful in the furture (the switch, not NZCONVERTIBLE).

 

Oh yeah I think it's flooded, plus I put some oil through the spark plug holes which I'm sure isn't helping. I pulled the plugs and gave it couple cranks then left it overnight. Lots of gas and oil in there.

"Pull the fuel pumps electrical plug off and crank it til it starts...then dies."
What about just pulling the EGI Inj. fuse?

I'm hoping all this is just TPS/Variable Resistor misadjustment.

I'll post what happens tonight.

Thanks HAILERS

 

Pull the fuse. I'm just old fashion. If the pump plug is pulled you have an advantage over the fuse pullers. You have ignition clearing the engine as you crank the engine if the plug is pulled. Not so with fuse pullers.

 

True. And it's no harder to pull that plug.

 

My car won't start.
It started right up after sitting 6 months, warmed up OK, then when it went to idle the idle was aweful, then I shut it off. I restarted it, it bogged at idle (like <500rpm) and then died again. Now it won't start. I've "unflooded" twice, and no luck.