Honda / Acura K20a K24a Engine Forum banner
Cancel
Create thread New Garage Forums

Let's talk TPS Failure

Tags
let's not
1 reading
Jump to Latest
127K views 296 replies 96 participants last post by  10cjennings  
#1 ·
I wondered if anyone else is having similar TPS issues.I have been having an ongoing issue with TPS sensors(any brand) failing on me in my K20R powered race car and I want to get to the bottom of it and fix it, or find a way to use a different TPS with a fabricated adapter.

I thought I may have a wiring issue,so I basically replaced every harness on the car with a brand new one.I realized that was not it after the failures continued.I thought it may be the brand of sensor.That came to no result either.So the last few sensors, I opened it up to discover the problem,small internal wire gauge breaking/failing.Is it vibration,maybe heat?

I know for sure it is not my wiring,each harness(chassis,swap,engine) and ground has been replaced and tested and the used ones are just as equal as the Brand new harnesses in performance.Sensors still fail.

In the pictures
The Left pic note the "aftermaket Omni brand" K series TPS: It has very tiny wire size that seems far too fragile to be on a vehicle.
Note on right the OEM K series Keihin TPS: Large wire like B series and durable.The Keihin downfall is the ceramic board sometimes breaks on them and I cant find one without buying a whole TB.Anyone have one:)

Since I am using aftermaket all the time,This is what is breaking on my sensors consistantly.The car runs awesome,then randomly shuts off and goes into limp mode 20mph or 2000rpm.I replace the sensor,recal the Kpro and the car runs again till the sensor randomly fails the next time.
 

Attachments

T
#2 ·
westup:

Thanks for the informative post.

But what's an economic solution to this? :)

i'm having the same issues as you, and my engine bay's getting loads of vibration due to teflon race mounts, I think you're right, vibration may be a major cause of TPS failure.

I've run through ..... 3 or 4 TPS this year alone.

Any way to prevent this from happening?
 
#5 ·
I have not seen or played with any of the Blox TPS's, BUT I have used the Omni-Power TPS and I know for a fact it is nothing but a stock Keihin TPS with a Omni-Power label over the Keihin engraving on the body of the TPS.

I have seen many a TPS fail, but only one of those failures was due to the internal design of the TPS. What I have found to be the worst offender of TPS damage is from either no gasket or one not thick enough, especially when utilized on ANY aftermarket TB. I dont know if it really makes a difference or not, but I also make sure to physically center the TPS rather than only rely on Kpro to electronically center it.
 
Save
Reply Quote Like Like
#6 ·
Skunk2 68mm TB went through 2 TPS sensors within a yr but fixed my idle probolem evertime , they car would stop running at a dead stop or would have to feather the gas pedal , blox tps didnt last any longer than the oem tps so i agree they are both the same sh!t
 
#7 ·
Great stuff guys,I knew I was not alone.EvoIX4me, with the blox sensor,did you have a chance to open it and see the inside? I want to compare brands and see if there is any consistencies with how they are made.

Talonracer that's good stuff. I use a voltmeter to set it like stock.Works fine 'till it breaks.You are slightly wrong imo about the Omni being real keihin.The Housings are,not the internals.The pictures sensor in my first post with the tiny wire and the pin,that is an OMNI sensor that has Keihin on the housing.They have sent me 4 sensors to try and fix this issue to no avail.

After much research and it is still ongoing,I have concluded there are only really two options for us.I have to type alot but it needs to be explained.

-Solution 1 someone on another forum said to me is to find an alternative TPS sensor,like a B series GSR or a ford focus,something that opens in the same directon and operates in the same voltage spectrum.If needed,have a billet adapter plate/actuator made to bolt these to our t-bodies and repin the plug to match.Like an RDX injector swap.

-My personal solution is for someone to make us a sensor like blox or omni does,and make it beefy like the real OEM Keihin contacts in my picture on the lower right.The trick is it needs to have an old fashined green fiberglass circuit board inside that won't break like the brittle ceramic ones are.This should be the best way, and someone can make money off this idea as well.

*Another solution one said to me,was drill a small hole in the new Aftermaket sensors,fill the area of the concerned contacts with silicon and hope that relieves some vibration.This is not needed if they use the curved,and wide wire contacts.

Both sensors fail but it seems the OEM(real keihin)last the longest from the data I am receiving.I know some race cars on the stock tps for many years now.These are each sensors' issue-

OEM = Built very well as far as contacts are concerned.Ceramic board fails,nothing else.Made in Japan.

Aftermarket = Wiring breaks but boards seem to stay intact.Very cheaply made in taiwan for mass production.
 
#8 ·
I was reluctant to do this because I didnt want to put any companies on blast.But I just came back from the garage and here you go,this picture is a BLOX TPS,you can see it is in everyway identical to the OMNI sensor in the center of the first post.Maybe a tad better as it has thicker gauge on the contact wires and actually a better contact on the rotating wheel as well.Still failed as you can see and by no means the beefy curved metal like OEM has on the right in the first post.

The only way to cure this problem is to make them like OEM HONDA keihin.
DO NOT be fooled by a company's sensor housing being Keihin,these are still not the same as the factory sensors.Honda needs to sell these seperate and they will make a ton of money.

BLOX,OMNI,BWR = Same cheap mass produced sensors,different sales person.
 

Attachments

F
#11 ·
Hey folks maybe you huys can shed some light. Im running a one off K20A Swap in my car now and have been getting some really strange issues.

I think its TPS related as it is Kinda loose. its temporarily in place BUT I wanna know your opinions.

Cold Start everything is fine.
Warms up everything is fine on constant light throttle.
Sometimes on full throttle its all good too
Sometimes I open the throttle fully and nowt. its like it doesnt know iv done anything for like a seconf than *Blap* it backfires and I bolt away with a jerk.
Usually once that happens it seems to gurgle and splutter a bit before acting like the Throttle body has a bit of moisture in it. I.e on idle it will rev between 900Rpm and 1800Rpm up and down..

Any help? pllleassee :)
 
T
#14 ·
Those symptoms were EXACTLY what happened to me.

dead zone during light throttle press, funny idling, Especially the part when you mentioned this problem was intermittent :)

which makes it so hard to diagnose.

Basically, I detected it when i hooked up the OBD2 to the Honda Interface Machine (HIM) and PGM-FI showed erractic readings from the TPS.

for the Gurgling and choking, you might want to check the MAP sensor, I had to replace that one as well.
 
#12 ·
The cyclic idle is the result of a vacuum leak, check all the vacuum lines, especially the PCV line. But the most probable cause is a stuck rotor in the Idle Air Controller. Start the engine without the intake pipe being attached to the TB and place your fingers over the IAC port on the floor of the TB and see if it helps the idle, if this helps repair or replace the IAC.
 
Save
Reply Quote Like Like
#13 ·
Here is a quick How-to and pic how I test my TPS and also set them.

I find 2 small sewing pins that I like;with the round top.Then I insert the sewing pin into the back of the sensor pin/plug from the wire side.be sure to get the pin between the wire and the wire to housing seal.This is also known as back-probing.

In this photo is an '02 K20A harness and t-body,where I am mock testing the Red/Blk middle wire.With the engine OFF and the key in ON position,take your voltmeter and touch the Black from the meter to a good car ground and the red to the pin at the plug.The manual says this should read .45 volts closed and about 4.5-5v open fully.If it does not you loosen the two screws and adjust the sensor accordingly. When I install new sensors this is how I do it,then recal the kpro min/max settings.

Next with the same back probe method, I am testing the Yellow/Blue wire.With the key ON and engine OFF,take the voltmeter black to the car ground and the red to the pin in the connector.It should have 5 volts roughly constantly,this is your feed source from the power.
If it checks out okay proceed with testing,if the voltage is suspect then check the harness for cuts or damage.Also check your 3 main grounds.

Then take 2 pins, one in the Yel/Blue and one in the Grn/Yel(the two outer wires). Take the voltmeter and set to the continuity test(speaker symbol) and touch the red to 1 pin and the black probe to the other pin.Your meter should beep saying the circuit has continuity.If it does not replace the sensor.
 

Attachments

#17 ·
I have seen far more MAP sensors go out of range or start having erratic readings, I have gone thru 2 since adding the K2 cams. I think I may try a different MAP sensor.

IIRC some Ford TB's have a electronically compatible TPS.
 
Save
Reply Quote Like Like
H
#18 ·
If you think your TPS is failing from vibrations, then it might be wise to try to add some dampening to the sensor's mounting points before trying to use an entirely different sensor. I would go ahead and purchase a sheet of rubber around 2mm thick with a hardness of 30 (Shore A scale) or softer. Cut out a piece the same shape as the OEM tps gasket and put it between the TPS and throttle body. It would be even better if you could also stick some o-rings on the bolts before installing them, but I'm not sure this would hold the TPS firmly enough to prevent it from vibrating out of calibration.

This isn't guaranteed to fix your problem, but it's not a bad start. If nothing else it should at least postpone your problem.

~russ
 
#21 ·
I know that every aftermarket TB I have tried has damaged the TB unless an extremelly thick TPS gasket(at least the thickness of 2 or 3 gaskets) are used.


And seeing that you have the TPS apart, why not simply solder on some more significant gauge wire to connect the board to the output pins?
 
Save
Reply Quote Like Like
#22 ·
I thought of doing that,but wire is not best,the first post bottom right picture is how Honda had it and that's most durable as far as the contacts go.

I am going to try and make a modified sensor using the OEM curved metal prongs and a modified board.The most difficut part is assembling the sensor housing again and hope the rotating wheel makes correct contact with the board.
 
#23 ·
You are right, wire would be hard to use, I am sure you could fabricate some spring metal strips that would work.

It may take some trial and error as far as getting the correct pressure on the contacts, too little and it would suffer from intermittant contact and too much pressure and the trace on the board may wear out to quick.

How about making an adaptor plate to use a Ford TPS?
 
Save
Reply Quote Like Like
#24 ·
After I examined the housings further,I see that the board rests on a lip inside the housing so,to me,there really is no wrong way to assemble the gap for the board to wheel.I also noticed the wheels' contacts are flexible and adjust to slight differences in gap,but need to be a certain distance for the proper tension.Just have to epoxy or JB weld the 2 pcs of the housing together again and try it.
If it works I will start a side job beefing up tp sensors,lol.
 
#26 ·
OK,Well what are you waiting for,open one up and show us the innards!!:D
I want to see if we have a pattern with design and failure.

If you need to know how,Just Dremel the glue looking area slightly all around and it will expose an edge of the 2 pcs of the case,then pry lighty with an xacto or small screwdriver and voila.
 
#27 ·
dont Honda of Japan sell the tps by itself? i know they did with b series. not sure with k series.
 
Save
Reply Quote Like Like
J
#45 · (Edited)
WESTUP,

Such an awesome thread. I've been going through this problem for over 6 months now. It started off gradually, then became like clock work, over 2,200 RPM and the engine would bog down and shut off, unless I shifted down a gear, then back up. I could get up to 48 MPH in 6th gear.

I have an '02 K20A2 in a '97 GSR. R-Krew headers, custom intake, K-pro

My first OMNI TPS sensor went bad.

My second OMNI TPS sensor is going bad.

I'm not sure what causes it.

I was very fortunate to have some serious Honda tuners look at my car this morning. They said the TPS was reading -2 degrees. I can't remember what they said, but they reset that. They also said, it's going to eventually go out and happen again. It did bog down on the freeway on the way home one time, I just shifted down to 5 then back to 6 and it worked...for now that is.

So I'm on the market for a TPS sensor and I will be following your thread. Thank you for taking the time and keeping up with the thread.

Before the two tuners looked at my Teg today, I had done everything I could think of: new fuel pump, new fuel filter, fuel injection cleaning service, switched out ignition coil packs and a MAP sensor from a good working 02' RSX-S (same problem), put my K-Pro into that same car (car worked fine).

Thanks again.
-JT
 
Honda / Acura K20a K24a Engine Forum
posts
2M
members
99K
Since
2000
A forum community dedicated to Honda and Acura K Series engine platform owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, power-adders, racing, maintenance, and more!
Full Forum Listing
Explore Our Forums
Parts for sale All Motor K series Technical Discussion 1992+ Civic EG / DC2 / EK K-Series Swap General K-series related talk Parts Wanted