Slowride R7

First I have been reading for days on this site and I am perplexed at the readings Im getting in comparison. Car has a low idle at times when in D (AT tranny) and coming to a stop. It will stall 1 of 30 stops (approx) but usually will hold around 500rpm.

Im starting with the TS sensor and this is the confusion. I get + volt on all 3 prongs at times and never a ground. The all times + prong is ok nearest the conn. lock tab.
The other 2 that are suppose to give a grnd and hence turn on test LEDs are also +.

They either have 1.7vlt or 12.7 when TS adj screw is turned clockwise. All the way out (left) the 2 prongs + 1.7. Going clockwise they will go to 12.7 at different positions of the TS adj scew.

All the FSM reading and some of HAILERS post say these 2 prongs should be (-).

This is a 87.5 GXL n/a with A/T trans

katkaroto

all that stuff is too hard to understand for me.. i went to banzai and got this.

http://www.banzai-racing.com/products_tps_tester.htm

very helpful tool, i had to do a lot of readjusting but my idle is correct. this is the most super effective way for me.. i read somewhere on teh forum on how to make your own.. but your probably going to take awhile trying to find it. good luck buddy.

Slowride R7

Thanks for the link bro. I have made a checker with LEDs but it will never lite if there are no GRN (-) on any of the wires or female conns.

Anyone? Why would I have (+) vlts on all 3 prongs on the Throttle Sensor ck connector? See my comment above for info.

Im new to this board but I have been doing a lot of seaching to try to address this low rpm issue.

HAILERS

Drive the car and get it hot.

Idle the car.

Backprobe the GREEN/RED wire on the TPS connector and leave that tps connector connected up.

What is the output of YOUR TPS green/red wire at idle as described above?

IF it's not one volt dc, then adjust the TPS screw til it reads one volt dc.

How did that work out for you?

HAILERS

When using the TPS check connector (the green plug, not the TPS connector as described above) put one meter lead in the socket where the BLACK/WHITE wire is. Put the OTHER meter lead in one of the other sockets. Meter on dc volts. Turn the TPS screw til the meter reads 12vdc. IF that happens, then that is when the ECU put a gnd on the wire other than the BLACK/WHITE. Should happen that way.

So what happens if you do it that way? One lead in black/white and the other in one of the other wires/sockets?

HAILERS

Let me claify the last post. You get the engine fully HOT.

Turn the engine Off then put the key to ON.

Postive meter lead in the black/white socket of the TPS CHECK connector. The green three socket connector.

Negative meter lead in the socket with the Blue/Red wire.

Meter on DCVOLTS.

Turn the TPS screw counter clockwise all the way til it almost falls out, but don't let it fall out and lose the spring etc.

Now turn the TPS screw clockwise while watching the meter. The moment the meter turns from zero volts to b/t 10-12vdc, STOP. I mean right now STOP.

Now put the negative meter lead in the socket with the blue/yellow wire. The meter should read b/t 10-12vdc.

Now slowly turn the screw anti clockwise til the meter turns from 10-12vdc to zero volts. STOP right there. Done.

Now put the meter positve lead in the back of the green/red wire of the TPS connector. Put the meter negative lead on a good ground like the battery negative terminal. The meter will read approx one volt dc. Maybe 0.95 to 1.05 vdc. Some where in that area.

ON the whole, it just makes sense to bypass the above and just flat go to the TPS connector itself and backprobe the output wire of the TPS, the green/red wire. Then with a fully HOT engine, turn the screw til the meter reads one volt dc. Done. Takes but a moment or so. No need to mess with the green connector at all.

One way to tell if the ECU is outputing a gnd, is to put your finger on the Blue solenoid or the grey solenoid. Then open and shut the throttle. One or the other should CLICK as you move the throttle.

Or, once you've set the TPS right, reach over and pull the plug off the Blue solenoi and put the connector back on. The solenoid should click as you put the plug back on, with a fully HOT engine.

Yeah. Just check the output of the green/red wire on the TPS for approx one volt dc with the engine HOT. Done in sixty seconds. Unplug NOTHING when doing this. Just backprobe the green/red wire with the meters positive lead. Neg lead to a known gnd. Done again.

FYI..........TPS have little to do with the idle. Gone.

Slowride R7

Thanks Hailers!

I have been testing it properly according to the FSM but I haven't tried testing it your way with the TS connector so I will do that tonight. I'll reply later on that test.

I just think something is wrong since I have + pwr on all 3 wires at the TS check conn. depending where the TS screw is set. A test LED connector would never work if there were only power on all 3. No neg = no voltage conducted.


Thanks again Hailers

slowride

crazyasu

this is a far superior way of adjusting the tps it allows very fine tuning:

http://www.fc3spro.com/TECH/HOWTO/TPS/tps.html

HAILERS

No it isn't. Just heat the engine up and adjust the TPS output to one volt dc. Done. THAT is superior.

Hell. I can put a finger on each of the solenoids and adjust the TPS with no lights, no meter no zippity.

The TPS ajustment effects idle little. If the engine is idling low, say in the 250-500 rpm range, then you might suspect the BAC isn't working right. Pull its plug off and see if the contacts in the PLUG are pushed back or not. Sometimes one will not be locked in the plug and will push back when the plug is installed, thereby not making contact with the BAC.

Auto..........uggggh.

There's a reason I suggested what I wrote in the above posts. The thread owner says the LED'S don't seem to be working for him. What turns the LED's on is a gnd output from the ECU to the check connector. I wrote what I did so he could see with a meter, if the ECU is outputing a gnd to the LR and the LY wires in the check connector. IF he never gets a gnd from the ECU to those wires (and the solenoids they are spliced into, then it's possible the ECU is kaput as regards the Relief and Switching solenoids.

If he can actually see an output of one volt from the green/red wire at the TPS plug, then the ECU should have been doing its job of putting a gnd on the LR and LY wires. If not it's a kaput ECU or open wire b/t the TPS green/red and the ECU.

Slowride R7

Ok, I have 1 volt at the TS connector with nothing on but the ignition swch. I started off at .95 and moved it slowly to 1 volt on the greenred wire of the TS conn. I started the car and rev'd it a few times and then retested. I had .88 volt so I did the adj again.. started/rev'd engine..then I had .97 so I left it at that.

So I do have 1 volt (at the TS conn grn/red) BUT I DO NOT GET grounds at the TS check (green) connector.

The only problem with engine is when coming to a stop (red lt etc.) the engine rpms drop often below 500ish and then rebound to around 550/600. Apprx 1 out of 20 stops the engine rpm will drop too low and stall. Starts right back up thank goodness.

I may have a dirty BAC or possibly a vacuum leak I suppose.

This is an Auto though. Rpms do drop when put in gear but this is just too low.

Thanks so far.. Anymore suggestions?

Slowride R7

By the way, I did do the riesistance check on the TS switch and all were within specs except the test between the a and c spade when WOT. As per the FSM there should be 5 +-1 ohm at WOT between the A and C spade on the TS swith connector. I am only reading a .58 k/ohm here at WOT. At closed throttle I got a 3.88 which is pretty close to spec at 5 +-1 k/ohm.

See FSM 4A- 50 for exact diagram of the resistance specs

HAILERS

I'll be back later, but go look at page 4A-31 and pin 2G and the result at idle or just with the key to ON. The figures like 0.95vdc or 1.05vdc constitue APPROX.

Remember the engine has to be HOT due to the water thermowax moving the throttle linkage if the engine starts to cool down while your doing this. In the winter this happens fairly quick but it is summer so you should have lots of time after the engine gets fully hot.

Seeing as how you have approx 1vdc at idle, per the FSM, then watch your meter as you slowly move the throttle to full open then back to idle. Engine not running, Key to just ON. Engine HOT. Meter probing the green/red wire of the tps connector. Later.

Low idle speeds on a Manual trans car are more closely related to the operation of the BAC. The BAC Should be trying to control the idle speed to approx 750rpm inn neutral. If NOT, then it might be a pushed back pin on the BAC's plug or a transistor burnt out in the ECU that drives the BAC. Or another thing. A BAC, with a fully hot car, usually is vibrating with the key to just ON. If not, then with the key to ON, move the throttle linkage open a bit and see if that does not trigger it to vibrate. Most people can hear this vibration/duty cycle with engine off, key ON. later

EDIT: The A-C call out in the FSM on that page is flawed. It's bull so to speak. It should be reading just the opposite of the A-B readings above it, NOT the same at idle and full open as the FSM says. I'm saying at Full Open A-C should read approx 1K, NOT 5 plus/minus 1.

Go to the series five FSM, non turbo, page F1-83 and look at the picture of the narrow range pot. Common sense says A-C isn't going to read the same as A-B at any given time. They are going to read the opposite at full throttle and at idle.

Flawed FSM.

EDIT: My bad. A-C will actually read Less than one ohm at full open not approx 1 ohm. Because when you read A-B at idle the adjustment screw was keeping the tps plunger from going fully inward, BUT when going wide open there is nothing to keep the pluger from going full outwards, so you'll get less than one ohm at A-C.

HAILERS

I might add, if using resistance with the meter, be sure to first touch both meter leads together and read the resistance. Write that down and subtract that from whatever figures you get when checking the resistance of the TPS. I've some long leads with alligator clips and if the leads are touched together I get 0.2 ohms that I have to subtract from any resistance readings.

FYI: Any time I use the LED lights to set the TPS, I can go back with a meter on the green/red wire and get Approx one volt dc. See what I mean when I say you can set the tps with a fully hot engine just by going to the green/red wire and turning the TPS screw til the meter reads one volt? Easier for me..........until I got a RTEK 2.1 which is even easier. It displays the TPS reading.

Slowride R7

Thanks for all your help Hailers

I really appreciate your input.


Good point. I didn't put much thought into it but that all makes perfect sense.

The car actually IDLE higher in D and coming to stops today on the commute to wk. Im afraid this is not the end though. I'll be looking for Vacuum leaks next and will be cleaning the connectors on all sensors I can get to this weekend.

Thanks again!

HAILERS

If I were you, and knew the TPS is putting out approx one volt dc at idle, fully hot engine, I'd reach over to the BLUE plug on the Relief solenoid and pull it off and then reattach it. You should feel a click from the solenoid when you do that. IF not, then MAYBE there is a problem with the ECU not outputting a gnd to the green check connector and the relief and switching solenoids. Not good IF you have to pass emissions.