Vtec Stutter: TPS?

[Benefit]

well, this just started happening, about a week ago i was driving the ITR around, and did a 0-120 pull and it was all fine, get on a backroad and chrip 2nd hard...and then it did not go into vtec when i switched to 3rd gear

pulled into a neighborhood, figured a plug came off, and thats what it was..the TPS plug had came off, plugged it back in and all was good

was driving it again yesterday, goes into vtec perfect, and then has a slight stutter between 7-8k rpms

now i inspected the TPS some more, the actual part where it plugs in is broken off.bad connection?..the head of the 2 screws that bolt it in are also broken off

the oil level is fine, infact i added a quart before i went out, so its not because of that...

could the hesitation/stutter be a cause of a bad TPS? it doesnt do it ALL the time either. or could it be a bad vtec solenoid? had a similar problem in my GS-R


pics of said tps...arrow pointing to where its broken...the plug doesn't "snap" in either, just sort of chills there

[SLOWR/T]

Vtec fluid is low

[patrick4588]

probably low oil pressure. the tps will only affect vtec crossing over at the high load threshold. even with the tps unplugged, it should still come on.

[Benefit]

lol VTEC will not engage with the TPS unplugged

[Homer Simpson]

probably low oil pressure. the tps will only affect vtec crossing over at the high load threshold. even with the tps unplugged, it should still come on.

Your car will not run properly with the TPS unplugged man.

[patrick4588]

i didnt say it would run properly, but vtec will engage.

[Benefit]

yea, hes just being stupid

[patrick4588]

no **** you. i have done it. i had tps issues and drove without one for a week. actually ran at the track without one. it will work. ******

[patrick4588]

the car does not drive well, but vtec will still come on. im not saying you should ever drive your car without a tps, but its not causing vtec to studder at high rpms

[Benefit]

ok so your answer is oil pressure?

[patrick4588]

more of a guess. it could be your vtec solenoid as well. did you change the oil pump when you did your rebuild?

[patrick4588]

i believe your head needs 54psi or something for vtec to engage. do you have an oil pressure gauge?

[Benefit]

ok, it only happens SOMETIMES. and oil level is FINE. oil pump is NEW.

[Benefit]

got an answer from ITR section of H-T

Yes an intermittent TPS signal wiill cause the symptoms you described.

Unfortunately, you can't replace the sensor side of the connector without replacing the sensor itself. And you can't buy just a sensor new, you must get the whole throttle body.

The bolts that attach the TPS to the throttle body are broken off from the factory. They didn't want the sensor to be replaceable. You can slot the bolt heads with a cutoff wheel and turn them out with a screwdriver to replace the sensor. However it will need to be calibrated within spec (clocked) or you will throw TPS codes for signal range.

You have three options:

1) Attach the connector in a way that it will not seperate. Perhaps wrap it generously in safety wire and/or tape, around the harness side connector and then around the TPS. itself

2) Replace the TPS with a used one (can find them online, but be careful because usually they have been removed for a reason... as in they are already bad) and calibrate it (requires multimeter & spec sheet).

3) break more off of the sensor side connector so that you can solder leads onto the pins (and insulate them sufficiently), then splice into you engine harness behind the grey connector.

Personally I would try #1 and then goto option 3.

[Benefit]

looks like your evil plan to diagnose my car with symptoms it does not have has failed, patrick.

[patrick4588]

you can buy tps's from omni now instead of having to buy a new tb. i think blox makes them too. i dont know what "evil" plan you think i have, but i was just trying to help

[ash7]

don't sweat him patrick, he's just upset about how his ITR is getting old and has a speech impediment now [the studder].

And you CAN replace the TPS without buying the entire assembly, individual replacements can be bought... or, if you're skilled with a drill, and some wire tools - you can utilize an used OEM replacement.

Before you go about all that hassle though, make sure your TPS is indeed the issue. Snag a meter, measure from the middle wire on the plug to ground with the ignition being in the "ON" position... should be around .50v with throttle closed.

Next go to the two outer wires, each should measure 4.5-4.6v at WOT.

...and that about does it for my "evil" plan. hope it helps
-jonathan

[Benefit]

yea i figured the only malfunction which could be causing it is the TPS, since its the only thing i have not replaced yet regarding engine function...

reps for everyone but i would still like some more input

[Benefit]

You must spread some Reputation around before giving it to se7en again.

[ash7]

-another option would be to hook an oil pressure gauge up to the diagnosis port on the front of the cylinder head next to the vtec solenoid itself, and stick the car on a dyno (if you have the hookup).

-may also be a clogged screen in the solenoid gasket (you said you've replaced everything, this is just a thought )

-what weight oil are you running?

-can you get it to do it consistently?

-check the screen at the bottom of your oil pickup tube in the oilpan, may have caught something.

-could also ohm out the wires running between the ecu and the solenoid itself (short maybe)

-does your speedometer flicker when this happens? (speed sensor wiring perhaps?)

...I'm out of ideas...

-jonathan

*edit* and thanks for the attempted rep however, I'm not so sure about the accuracy of the posting from HT - vtec requires three things to engage from what i remember: car motion, oil p, and water temp.

[Benefit]

yea the speed sensor has BEEN flickering, the wires are loose...could that really cause it? that was like the first thing i thought of but i thought it was too far fetched to affect vtec function

and to clean the solenoid screen...i just spray some carb cleaner in there or what?

i run 10w-30...and it doesnt do it consistently

i actually have 2 autozone faze oil pressure gauges sitting in my garage...electric not mechanical, how would i hook it up to said location?

[G.C]

I had a bad tps on my lude one time. It did the same thing you said. Stutters every now and then. bought a new one and adjusted the voltage and it ran perfect . When you install the new one, make sure you do what se7en told you to do.

[G.C]

Just take it to the shop before you buy all these expensive parts tho. Save you time and money and headache.

[ash7]

yea the speed sensor has BEEN flickering, the wires are loose...could that really cause it?

and to clean the solenoid screen...i just spray some carb cleaner in there or what?

i run 10w-30...and it doesnt do it consistently

i actually have 2 autozone faze oil pressure gauges sitting in my garage...electric not mechanical, how would i hook it up to said location?

yes, that is your problem then.

I ran into the exact same problem when i had my crx with a high comp. B20vtec (the one with the S2000 cluster installed). I could never get the speed sensor conversion correct (obd0 requires the mechanical type sensor), and as a result, the computer would not ground the solenoid. I tried a couple different options; mechanical convertors (two of those), and then just modifying a speed sensor. Neither of those worked and the engine never engaged VTEC. However, with a VAFC installed - ran like a scalded dog.

If you're having speedometer flickering problems, either the distributor's Ignition Output Sensor is about to give up the ghost, or you have a loose connection on your speed sensor. If the ECU thinks (even for a split second) that the car is not moving, it will disengage the solenoid. [we all know that vtec does not engage while you're sitting idle at the track reving the engine]

I'd be willing to bet you 100$ via paypal.
-jonathan

[Tech5]

lololol

[Benefit]

se7en your the man....

i had to cut and splice 2 wires to the speed sensor...i think one of them is faulty causing the flickering...

[Benefit]

yeah...im just gunna replace the entire plug...i re-did the 3 wires going into it , looks like the black one(ground) is not making a proper connection...but i did what i could

speedometer works fine now, vtec is very fluent..

just got a lil worried cause the car gives me no problems, except for it burns oil, but what honda doesnt