DR_Knight

iTrader: (23)

so i failed smog the other day do to 2.5 times the amount the limit of Hydrocarbons. I did alot of research and i figured my acv might be bad. I tried pulling off the hose that attaches to the top of the split air pipe, and i don't feel air coming out of the hose at all at any rpm.

what rpm should air be flowing out of here? allowing oxygen to flow to the catalytic converters

and when should the air be expelled out of the dump hose for the acv?

should i even be able to feel oxygen flowing out of this hose?

fastboy2468

Look Here:

http://www.rx7city.com/Manuals/89-91...mission_NA.pdf

F1-67 Is the item you want.

jinxed4dub

iTrader: (7)

You need to eather shim the ACV or T into the line before it goes to the ACV to constantly run O2 to converter.

HAILERS

A very small volume of air passes thru the split air pipe on a stock RX. In fact I remeber following the BOOK and had to put the split air hose in a bucket of water to see the difference in volume as described in the BOOK.

The manual listed above shows how to check if air is coming out the split air pipe.

At idle and low throttle range, the ACV sends a large amout of air to the exhaust ports on the engine, not the split air pipe.

If you did a emissions test that was done on *rollers* try to post your results for both low and high speeds . In Tx the speeds are 15mph and 25mph.

Passing the low speed but failing the high speed could indicate the 02/ECU isn't going into closed loop.

Failing both low and high could indicate a failed ACV control system or just a bad converter. Converters can be had cheaply for approx 125bucks.

The ACV is controlled by the ECU via the Relief and Swtiching solenoids. That signal from the ECU to the relief and switching solenoids is controlled by a correctly set TPS i.e. a TPS output of approx 1vdc at idle with a fully warmed up engine.

Approx 1vdc can be anything in the .95 to 1.05vdc to be conservative about it. Can be even further off and still be APPOX 1vdc.

There is no need to plumb air straight to the split air pipe at all. EVER. Unless one does not know what he's doing. Lotta that going around.

jinxed4dub

iTrader: (7)

Thats just how alot of people with bad ACV's pass smog. just constantly delute the converter. It cant hurt could it? IDK thats why I'm asking.

j9fd3s

iTrader: (3)

it works better if you shim it to put air into the exhaust ports

pogi1

iTrader: (8)

Its DUE not do dumbfuck MWUAHAHH!!!!!!!

jinxed4dub

iTrader: (7)

yeah, I didn't catch that. don't pull the air pipe with cats installed. they can overheat and fall apart. Mine did with the pipe attached. sounded like I had tons of rocks in my cat.

yeti

iTrader: (1)

Hey HAILERS if my relief solenoid isn't working and the voltage is at 1. then what?

s5 vert.

HAILERS

Pull the blue plug off. Key to ON. The black/white wire should have batt voltage on it.

Put the plug back on the solenoid. Key ON. Backprobe the wire that is NOT black/white. It should read under 2vdc. One vdc is less than that.

The engine should be fully warm when doing the above, although the black/white will have batt voltage anytime the key is to ON.

OR with a hot engine, just pull the blue plug off the solenoid and then put it back on several times. You should be able to FEEL the solenoid pull in. Actually hear it do so also. Meaning its working.

Then with a HOT engine and at idle, go over to the ACV and pull off the LARGE black hose on the ACV. The hose that is close to a inch in dia. Then feel the air coming out of the ACV where that large hose was connected. A small amount of air will probably be felt. Now at the same time reach over and pull the blue plug off the relief solenoid. When that is done a large volume of air will be felt coming out the large port on the ACV. Meaning the relief soleniod is controlling the ACV.

That's for a non turbo car, not turbo.

If the black/white wire has but one volt when the plug is off the solenoid........there's something terribly wrong since the black/white wire on all the solenoids should have batt voltage when the key is ON. I imagine yours does have 12vdc and only drops to one volt when the key is ON and the elect plug is connected to the solenoid (voltage drop is normal when the ECU puts a ground on that wire that is not black/white on the elect plug ).

yeti

iTrader: (1)

I meant the tps had one volt sorry but I will check this soon. Only thing at this moment I know for sure is the ECU gives me the error code for the relief solenoid.

Basically I'm going to install a cat soon and I don't want to destroy it.

HAILERS

Then go to the RELIEF solenoid and pull its plug off. With key On see if the black/white wire has batt voltage. Should

The reinstall the electrical plug and with the engine fully hot, backprobe the other wire on the relief solenoids plug and see if it reads less than two volts dc. Better still pull that plug off then put it back on several times. You should feel the solenoid click each time proving it's getting a gnd signal from the ECU.

If it does not click each time, and did have batt voltage on the black/white wire, then I'd ohm out the other wire from the solenoids plug to the ECU's plug..... a blue/yellow wire.

If the TPS reads one volt on the narrow range TPS output (green/red wire), then the ECU should be sending a ground signal from the ECU to the relief solenoid via the blue/yellow wire.

The output from the narrow range TPS does not have to be exactly one volt. It can be off like??? say .8vc to 1.10vdc as an example. I'd say anything in that range of .8 to 1.10 will result in a gnd output from the ECU to the relief solenoid.

yeti

iTrader: (1)

I'm just going to keep updating. I tested the black wire it has battery voltage. I both pulled the plug off and back probed. There was no clicking while putting it on and off. While back probing the voltage was also battery. I don't know why? Now I have not go to back probe the narrow band on the tps. According to my safc-ii it's .5 volt I believe. I'll check again for sure in the morning. Also I forgot to pull the hose off but I'm assuming with everything else messed up it's probably not working. Again I'll check that in the morning too. Unless it's snowing real bad.

Also I did this testing with both the car off then on.

Would it be safe to assume that the solenoid is bad? I'm not sure when I'll be able to pull the carpet back and ohm the wire. What would a good ohm be?

HAILERS

Those solenoids rarely fai.

Understand this: the ECU puts a gnd on that L/Y wire when the TPS outputs a proper voltage at idle which is approx 1 vdc.

If the ECU is outputting .5vdc, then most likely the ECU will not put a gnd on the L/Y wire and the solenoid will not click/engage.

Let it be known that a cold engine will cause the TPS output voltage to NOT be 1vdc because the throttle linkage the TPS is attached to is moved by the water thermowax's piston therefore changing the TPS output from what it would read if the water temp was HOT.

So you want to make sure the TPS output is approx 1vdc with a HOT (fully warmed up engine) engine. Then check the relief solenoid.

The relief solenoid is triggered to be energized by the L/Y wire that is attached to the ECU. The ECU puts a GND on that wire if the TPS is rigged right, which means an output of approx 1vdc at idle when the engine is fully warmed up. Last time I looked the TPS will output approx 1vdc with a engine fully warmed up and the key to just ON and engine OFF.

One of the functions of the TPS is to control the Relief and Switching solenoids which in turn control the ACV. Tha't why people hear a clicking sound when adjusting the TPS using the *two light method*. The clicking is the relief and switching solenoids coming and going as the ECU puts a gnd on them.

By ohming out that L/Y wire I mean put one meter lead on the end of the wire at the solenoid and the other meter lead on the other end of the wire located at the ECU plug and then put the meter on Ohms. The meter should read less than an ohm or more like .2 or .4 ohms. I really doubt this needs to be done. It's just done to make sure the wire isn't broken b/t the ECU and the solenoid. Most likely not so don't bother right now.

yeti

iTrader: (1)

hm.. Well then.. I may have another problem then.. A long while back when I was messing with my TPS settings I used the two LEDs in the TPS test plug method (excuse me for not remembering the name but I trust you know the method I'm referring to). Anyway at one time I was able to get one or the other light to illuminate or both or none. Now, I'm unable to get one of the two LEDs to illuminate at all. (Well let me check this to be sure it never illuminates but I'm almost certain it never would.) Now all this started happening after I installed a RB head and presilencer. But now I'm going back to a cat.

HAILERS

Setting the TPS using the two LED light method requires a fully warmed up engine with the engine turned off but the key to ON. IF the engine is idling the two LED method will not work right. See FSM.

The green three socket TPS connector has one wire for power that is black/white.......one wire that is L/Y (spliced to the relief solenoid) and one wire L/R (spliced to the switching solenoid).

When the TPS is adjusted to an output of approx 1vdc, the ECU sends a ground signal to the L/Y wire which results in the one of the LED lights to light up and also sends a gnd to the relief solenoid causing it to energize (click).

A fully HOT (fully warmed up engine is REQUIRED).

yeti

iTrader: (1)

ok well excuse my last post I did manage to get the tps below 1 volt and I heard the click however the blue connector (the L/Y wire) on the solenoid is still at battery voltage and I had to screw the TPS adjustment ALL the way in. I have not messed with the idle screw yet as I have to get ready for work but that should have any effect on the relief not working. I have unplugged the battery to reset the ecu but not retested.

Also on the plug for the LED tester the L/Y does not light up. I have not measured it for voltage yet because of time.

Thanks for all your time though. You are a great help and very much appreciated.


The engine is fully Hot and was off during all tests. Unless otherwise specified.

HAILERS

Two solenoids can cause a click when the TPS screw is adjusted. The relief solenoid who's plug is blue and the switching solenoid who's plug is grey.

Sooooo, I guess it could have been the switching solenoid that clicked. If you backpobe that solenoids plug and if it was the one that clicked, then the voltage on its L/R wire would read under 2vdc showing it got pulled in by a gnd from the ECU.

Should'nt have had to turn the TPS screw all the way in to get things to work. I'd unscrew it til the screw is ALMOST all the way out, then adjust it in with a fully warmed up engine with engine off and key ON.

yeti

iTrader: (1)

It was the switching solenoid that clicked. But now if I unscrew the screw like you said the voltage is going to be too high right? cause it took me until it being all the way down before it hit .9vdc. I do have another TPS but I'm not sure if it's any better.

Could the engine bay getting soaked cause this problem? Also if I was to find a s4 solenoid would you think I could use it to test this out? I would use s5 but there are only s4 in the junkyard if that is an engine at all.

HAILERS

All those solenoids are the same item. It's just that the small filter can be pulled off and put one of the other nipples that makes them different. So just swap one of the other solenoids to replace the relief solenoid or if the blue elect connector will reach another solenoid put it on another solenoid and see if it clicks.

Seems to me there is another problem here. Things shouldn't be happening as you describe. I'd guess that the fast idle cam isn't seperating from roll pin on the water thermowax assy. That act might be causing the throttle linkage to be effecting the TPS setting.

Last time I looked at a non turbo throttle .......I found it difficult to determine if this is so without removing the throttle body to see the linkage. Sorry, I don't have the patience to explain the water thermowax and how it works anymore. See the FSM and pictures of the water thermowax is the best I can do.

Basically the water thermowax moves the throttle plates to the slightly open positon when the engine water is cold. This is done to keep a cold engine running til the water gets warm/hot. As the water warms up the piston on the water thermowax extends and pushes against a long screw that in turn is attached to the throttle linkage. When the piston extends far enough it pushes a cam off a roll pin and the throttle plates close completely.

So you can tell from the above that the water thermowax moves the throttle linkage which is what the TPS plunger rests against all the time. When the water is cold the TPS output will be a higher voltage than when the engine is fully warmed up. Like it might output 2-3vdc when the water is cold but read one volt when the water fully heats up and causes the water thermowax's piston to fully extend which causes the throttle linkage to go fully closed.

Or I wonder what the result would be if you put the elect plugs on the solenoids. Then somehow crack the throttle linkage to full open with say a screwdriver. Then with key On, slowly push the plunger of the TPS in while listening to the solenoids click. Do that to listen to the relief solenoid to see/hear if it clicks or not EVER. IF it does click, then I'd check into the water thermowax being stuck or not getting any water to it to make its plunger extend or just out of rig for some reason or other. How to rig it is in the FSM fuel and emissions section.

I'd try the cracking of the throttle linkage first. It does not require tearing anything apart and confirms if the ECU is outputting a gnd to the relief solenoid.

No, I doubt washing the engine bay did the relief solenoid in. Not likely at all.

HAILERS

https://www.rx7club.com/showthread.p...ight=TPS+SCREW

That thread shows a jpg of the water thermowax linkage I believe.

yeti

iTrader: (1)

Ok, I'll check when I can it's snowing about 6 inches out there which is a lot for here. But yeah I had the basic understanding of the thermowax. While I await better weather I'll go ahead and test my other tps just incase I have to switch them out. Also I'll read up on the thermowax system. Thanks A lot though for all your help.