I just replaced the TPS with a known working TPS, I adjusted per FSM using the light method. I tried to use multi meter for testing, but couldn't move throttle and keep probes on contatcs.

The problem I am having is this. I get really bad hesitation around 2500 to 3000 rpms

never happens in 1st gear, sometimes in 2nd gear always in 3rd and 4th and 5th gears.

I also have 3 extra grounds I added around the engine.

Is this known working TPS junk also?

could this be from plugs?

ideas?


Thank you
Levi

 

Check your grounds?

 

Check the resistance of the TPS when moving the throttle. It should be a clean sweep with no breaks.

 

Tune Up that motha... It will eliminate all stupid variables.
Then you wanna clean the grounds on the top of the intake and on the engine when all the intake manifolds are off.
Take LOTS of pix and tag everything to where it goes if you do this.

 

Yup, S4 ground problem. Check all the grounds like, the one under the intake, the one on top of the intake, the one from the pressure sensor to the engine, the one next to the power steering pump on the shock tower. Clean all the contacts with a wire brush. For some reason I couldn't get a good ground on the one on the shock tower so I added another wire that went over the ground bolt to the top of the tower where the shocks bolt on. That way I knew I had a good ground and I knew for a fact that harness was getting a good ground too.
Do a sweep test on the TPS there shouldn't be any drop offs or breaks in the sweep. You said you couldn't use a multi meter? hook the positive probe to I think its the green wire with a stripe (the top one) and the negative probe to a ground. You should have 1 volt at a idle with a warm engine (it doesn't have to be running) just have the key on. If you can't get a reading or it is way off try one of the other TPS wires and do the same test cause I'm not 100% that its the top wire. Do a tune up too...

 

Just checked grounds they are clean and tight.

why does the key need to be on to test the TPS with a meter?

Don't you disconnect the TPS from the harness to test? Or at least thats what I did.

I can't hold the probes on the contacts of the TPS, while using other hand to move throttle to WOT.

Do I need another person to do the throttle?

I will check plugs,again when I get home, I just did a tune up 1 week ago.found my trailing plug on rotor #2 cracked after 1 days use......ran crappy without that one plug working.

Maybe its that again.

 

Just unplug the tps from the harness
it should read around 1k at closed and 5k (+/-1) at WOT.

Heres a write up I think from Ted's site:
http://fc3spro.com/TECH/HOWTO/TPS/tps.html

 

The TPS gets blamed for everything. If you're sure your grounds are all there and are making clean contact, then it may be your secondary injectors or the actuators for the secondaries. You need to check all this out.

 

Agreed.

BTW, Is that the Hatteras light house in your avatar?

 

seems odd to me that this started yesterday, while coming home from work. It almost stalled, but only one time did it almost stall, went down to like 500 or maybe 400 and then came back up.

I changed and adjusted the new TPS per Ted's writeup.

I have 1 real problem. How do you hold 2 probes onto the contacts of the harness, while moving the throttle to WOT?

is there something I am missing?, like a freind to hold something.

I also noticed this afternoon, that my vaccum guage is reading 5 psi lower than its normal 14.7.

@ idle it was around 14.7, since my new problem arised, my vacuum is reading 10 to 11 @ idle. It doesn't build negative vaccum anymore while driving in a certain gear without more throttle applied. Does that make any sense?
I will say that since I changed the TPS, the car pulls harder, when it doesn't hesitate. The car is 100% smoother running and the explosions from inside the expansion chamber do not shake the entire car anymore.

is there any way to test grounds to ensure the resistance is not to high on them?

what would be the desired resistance from custom grounds?

Thank you so much for all this help.

 

You can stick the multimeter probes through the rear of the plug (where the wires go in) and it should stay in there. Just slide it next to the wires and it will hit the crimped connection and make contact.

It's inches of mercury, not psi. If you're only pulling 10 in/hg you've got bigger problems than a tps... namely a bad engine.

 

I never thought about the back side of the connector, thank you for that advice.

You're right about Mercury, again my fault, didn't think when I wrote it down.

let you guys know what I find.

Thanks for the help, if any more ideas let em rip.

 

Alexdimen: Actually, it's the Bodie Island Lighthouse at the Oregon Inlet on NC's outer banks. Probably 50 miles north of the Hatteras Lighthouse.

 

You can check the grounds by going to the page in the FSM where it says what every wire is on the ECU connectors in the interior. The FSM will show you a picture diagram and then give you a wire code like "3g" then you look on the list and find what that wire does. Do this just visa versa. Look up ground in the list and go to the connector and test for a ground. If there isn't one to that wire or if you don't get the right ground Ohms then follow that wire back and solve that problem. Only 10-13hg? That would be at least a vacuum leak and the worst an engine going out the door. But can I assume it starts and fine and you have good compression? Whats the milage on the engine? My S5 NA has about 60,000 on the engine and it gets me 16-18hg of vacuum, Id say that is normal. Then again my new TII engine only gets about 12-13hg of vacuum at idle and it runs and idles perfect (it'l come up some as I break it in). Your engine killed one of your plugs huh. I've never had that happen on any of my rotaries past and present...
But ya, you should have a little more than 10hg or you'll have idle and dieing problems. These engines like to stall out below 10hg at idle.

 

No problem. I would definitely test my compression if I were you. Good luck.

Oh, I gotcha. I usually try to get down there every summer. Camping in Ocracoke is awesome if you pick the right time (avoid the bugs and insane heat).

 

This is what I found out.

The plugs are fine, I pulled them all.

Compression is also very good.

Readjusted TPS, I left my jumper wire in place.

TPS follows the resistance range fine, seems to lose its adjustment after 3 or 4 test runs. What I mean is shutting the car down rechecking, start back up drive 2 miles at various rpms, etc.

I get this odd clicking noise, thats how I noticed the TPS tells me its wacked out.

So I readjusted it again, it seems the hesistation moves around the rpm ranges.

sometime it was around 2000 rpms, now this morning its about 3000, maybe 2800 rpms. Then sometimes I can make it not happen if I progessivly push the pedal down and run through the 2000 to 3000 rpm range. Then I can get the backfiring or what not all the time, and its really using my gas. 9 miles to gallon if that.

but when the TPS is adjusted and holds it. Gas mileage is around 150 to 170 miles per 1/2 tank for gas with oil mixture.

Thank you guys!!


I assume any TPS will work, even a T2 TPS? Right? Cause I got another one here 2 the house. guess thats next to try, but gonna test it before install occurs.

 

You unplug the TPS at its connector only to check if it shows resistance with no breaks. Once you do that, you plug it back in to adjust it.

The TPS is adjusted at the green plug (near the AFM if IIRC) with ignition on. As you adjust the TPS, the computer sees the resistance and grounds one or both leads, depending on adjustment, which turn on the light. The leads are actually connected to the secondary air injection emissions system, but don't worry about that detail.

One common mistake is adjusting the TPS without the car being fully warmed up. The fast idle cam needs to move away from the TB to let the throttle close fully. You can check at the back to make sure this has happened.

I have focused on the TPS, but as mentioned, you could have other problems.

Edit: Just read your post about the clicking. That's the computer grounding some solenoids (as mentioned above, this would also be turning on your checker lamps). This is supposed to happen as you adjust the TPS.

 

This is what I have found, the light method isn't very accurate. The TPS and light flicker only the red light does this, when I get adjustment near to perfect and both lights lit. I back the screw down until the red one shuts off, I also noticed the more or less I turn the screw, it changes where and when the hesistation occurs. I am thinking if I can get it right, I shouldn't have any hesistation.

I am going to try this T2 TPS I have.

I am also pulling 14.7 inches again @ idle. seems to be very dependant on where I decide to turn the screw to but at same time its makes alot of sense, being it controls fuel air mixture while @ idle.

 

*******its makes alot of sense, being it controls fuel air mixture while @ idle.********************************************* ************

Stop listening to whoever told you that.

 

Low vac is always scary. Glad your motor is OK. What numbers did you get?

The TPS resistance is going to change as the engine coolant temperature changes. You are adjusting it fully warmed up with the connector unplugged from the harness, right?

I've never used the light method. I don't see a need to. I just take a MM and get it on 1k ohm or whatever them manual says. Then you do a sweep to check all values and WOT value. After driving a while I'll check it again at idle position.

 

Well let me see what I now know.

The vaccum has gotten a hair stronger, its now pulling 16 maybe 17 inches @ idle.

while cruisng, I can get the vaccum to pull almost 13, but most times 11 inches. Let off of gas and the vaccum goes to right around 20 maybe 21 inches.

For compression I got 110, 115, 118 on front. 108, 110, 105 on rear. not too bad for 140 thousand miles.

I noticed the slower I go with the TPS on a MM the voltage does show you whats happening. Sometimes, I went too fast and got crazy readings while doing a sweep of the range, why nobody tells anyone this, is beyond me. My car now has a electrical problem, becuase I now have lights that come on the dashboard center info display.

I assume, I might be able to fix this by swapping out the entire computer?
I have a 86 GXL auto parts car.
Can I use its computer and will it work?
This new light issue, is it caused by broken connections on the computer under the passenger carpet?

I am going to try to manually use a MM to fully adjust the TPS to read exactly 1k OHM at idle. I don't think I shall use those lights anymore, they suck!




Thank you

 

The Warning Light Cluster has no relationship to the ECU whatsoever. You need to say which lights come on in the Warning Light Cluster. If all the lights come on, then it's an alternator problem, whether the alternator itself or the ouput of the white/black wire from the alt to the Alt relay in the CPU.

There is no ECU just dedicated to the automatic transmission cars. They're all the same for a given year. Like any N326 or N327 will work in your car.

Your vacuum while driving is Normal.

*Sweeping* with a digital meter is not as good as if you had used a analog swing meter.

Setting the TPS should be done with the engine HOT. If you checked the sweep of the TPS with a digital meter and went slow with the opening/closing of the TPS and saw no *opens*, the reconnect the TPS plug and backprobe the green/red wire on the TPS plug (EM harnesss side) and with the engine running and fully HOT, set the TPS so it output ONE VOLT DC on the green/red wire. Done.

Either that or go to the three socket, green TPS check connector and use the two LED light method with the engine OFF, key ON. You'll find that when through the output wire on the TPS plugs green/red wire will be approx ONE VOLT DC.

Any of the three methods will work and the end result will be a output of the TPS to the ECU of approx one volt dc.

The clicking you hear while setting the TPS is the output from the ECU to the Switching and Relief solenoids. That is one of functions of the TPS's output..to control the emisisons solenoids mentioned. Along with cutting fuel on one or both rotors when you lift off the pedal while driving. Depends on how far you lift off the pedal as to whether one or both rotors gets its fuel cut. See Training Manual that is online.

 

Thank you Hailers!! Thank you everyone!

Okay, now. I get 3 lights on, when I put the key on the "on position" my clock goes out, I have lost all my inside dome lights.

One light is a hatch open. I have to recheck I don't want to post bad data.

 

Clock going out intermittently is what is called a cold solder joint. The cold solder joint is Probably right at where the elect plug attaches to the Warning Unit. The solder on the jack on the Warning Unit if heated and reflowed will probably make the intermittent clock become a steady light. Common problem on early series four cars.