I have a 2000 Honda civic D16Y8 with a Skunk2 70mm throttle body and stiff engine mounts. Ever since putting on the stiff mounts, the TPS tip eventually breaks off inside where it attaches to the throttle plate. I'm assuming this is due to vibration. I tried looking for a heavy duty throttle position sensor, but there doesn't seem to be any.

Is this a common problem? I'm wondering if the skunk2 throttle plate has too much wobble or something and maybe I should just go back to the OEM. I guess I'll have to take it off and see what's going on. But maybe someone has had this problem before before I start looking for stuff.

Okay, so I have this throttle plate - . One reviewer says
Too late, already bought it.

Didn't realize the Skunk 2 was a crappy product. I guess I should have known something was up when the plate was sticking and I had to adjust the throttle screw.

 

Depend upon if you have the billet or alpha throttle body. The alpha was much more robust than the billet series. Even Skunk2 admitted that.

This will be moved to the appropriate section for more analysing

 

1) That throttle body is WAY too big for your engine if it is essentially stock... meaning bolt on mods only and no significant internal changes. It is a common misconception that bigger throttle bodies make power on small displacement engines. When it comes to N/A engines, the fact is that peak power is only improved if the breathing ability of the engine itself is greater than the flow through the throttle body. This creates significant vacuum readings within the intake manifold and can be discovered with a datalog and a full throttle pull to redline in third or fourth gear. Here's the rub: If you go too big, the air velocity drops from just above idle to the high side of the midrange... maybe within 1500 rpm of redline. Lower velocity means lower efficiency... which means a loss in HP.

2) If you don't have the intake manifold inlet matched to the diameter of the back side of the throttle body, the turbulence that it creates at the perimeter will likely reduce hp all across the power band. It will make more noise... just not more power.

 

Huh. Well I bought this off ebay with the manifold - https://www.ebay.com/itm/Skunk2-Pro-...-/291152690522. It claims to be Alpha.

Truly, I didn't have a problem until I installed the stiff engine mounts. But I needed them as the motor rocked back a lot at around ~400hp. Had me worried. Perhaps this isn't really designed for high boost cars?

I'm going to be honest. I don't know that much about intake airflow when it comes to N/A, as I assume it really has no effect, unless it's WOT. I just needed a new manifold after converting the car to manual from automatic. I'm running a large turbo, so I kind of figured it was unnecessary either way. Besides, I was looking more at high rpm efficiency for hot lapping. Even though as a now daily driver, I probably should have gone with a smaller turbo for better low end spooling and efficiency. But I have the manifold to go with that throttle plate. So I don't think that's really a problem. Maybe I'm misunderstanding what you're getting at though.

This is all seems to have started after installing the stiff engine mounts. I had an IACV stick open shortly after; the rubber gasket for the plunger moved out of its socket. But I haven't had a problem since replacing it with a high quality one (I cheaped out on the first one). I just have a problem with the TPS breaking every now and then and a higher idle, though I have no vacuum leaks in the lines (I plugged everything off at one point to make sure). The intake gasket is sealed too. IACV and Map sensor also are sealed. And the IAT sensor is sealed (I moved it before the throttle plate). So I think that leaves the throttle plate.

 

Vibrations alone can destroy TPS sensor bracketry considering its location. On the Alpha, it could be the plate, but after owning 4 of them, and a few friends with over dozens of them in the last couple of years, I've yet to see the Alpha plates become an issue. Mainly because they use the same material for the plates and screws, and not different ones (with different heat absorption characteristics) as with the Billet series. Those had horrible issues.

I don't think its the alpha itself. I agree with you that it's in the mounts and something is obstructing it to a point of breaking off, and is exacerbated due to the vibrations.

 

Actually, had you said you were turbocharged and making nearly 400 HP... I wouldn't have told you that your T/B was too big. LOL.

It is possible that the stiff mounts are creating enough vibration to damage the TPS, although that isn't were I would focus my efforts. You did mention that you changed intake manifolds at the same time you got the T/B, I would check your throttle cable and "over travel" ability of the throttle blade wheel itself. Slowly moving the wheel from closed to fully open may allow you to "feel" if the TPS sensor itself is being stressed or strained from over travel. If so, you may be able to "open" the two metal prongs in the opening to allow a bit of additional movement inside for the TPS position pointer. You can also move the TPS body to lower the idle (closed) voltage allowing for more travel to reach WOT. This will require a TPS position reset in your engine management. It is easy if you have Hondata s300, but it can also be done with others.

 

Hmm, okay. Thanks for the information.

Thanks for the suggestions. It's negative outside and I don't have a heated garage, so I'll have to check this out some other time. But from a quick check, the throttle does seem to open a little more than 90 degrees before it stops, so I think you may be on to something.

 

Update:

The Edelbrock throttle body I bought was refunded as I guess they don't sell it anymore.

Took the tps sensor off and found that it wasn't broken like the other one like I had thought, despite having the same symptoms (I guess I should not have assumed), but that it had water/methanol in it, which seems to have destroyed the sensor. I did recently add methanol-water injection, since I can only get 91 octane in North Dakota. So I guess that's a problem...Did some research though and apparently the Alpha series Skunk2 throttle body does have sealed bearings, so I don't know why the water/methanol got in there. I bought this instead Omnipower 68mm T-Body, so maybe I won't have that problem with it. I guess I'll take apart the skunk2 and see why it was leaking and if there is anything that can be done to fix it, since I'm curious now.

 

How far was the was the methanol injector from the throttle body on the inlet pipe? where was it located? Remember, methanol is corrosive to rubber seals, so if its not being atomized into a mist because it is too close to the throttle body, it will cause sealing issues regardless of company.

 

Ohh, it's literally right before the plate on the silicone coupler. I used a sandwich adapter instead of tapping into the aluminum pipe.

So I definitely should move it farther back?

 

Oh yeah, you're definitely too close to the inlet. It's to the point where the methanol injection is not properly atomizing to mere droplets. Your concentration percentage might be low (depending upon what you're using) which will affect that, but more importantly, you're just way too close, to where you're destroying things by way of corrosion.

You need to tap into the aluminum pipe, and not use a silicone hose to put the injector in. There's too much instability, and the methanol is just pooling around the silicone, possibly corroding it. Get rid of the sandwich adapter completely.






You want to be at least 3-6 inches out from the Throttle body, on the end of the intercooler pipe going into the throttle body, at about a 15 degree angle towards the throttlebody and not deflect off of the sides of the intercooler pipe. Even post-charge air going into the intercooler, your inlet temperatures are are still high enough to properly atomize the methanol, but you can't have it at the plate itself.


You never stated if you were indeed forced inducted.... But in the event that you are not; If this is an NA car in which you're using this, stop using the methanol/water injection completely, before you damage something else, by way of compressing water You're not creating enough heat in the intake to atomize the methanol, (and if it's not doing that, then it certainly won't atomize water! ) Switch to another method of gaining octane such as an octane booster or other toulene additive, E85, or (in some states) pump race fuel (leaded 110octane). You're not going to get the methanol to work on an NA D-series car like that.

 

Sooooo...I did what you said and tapped it into the aluminum a bit after the intercooler so the nozzle is still above the pump. I've been driving it to and from work all week with lots of hard boosting and datalogging. And the sensor hasn't had any issues whatsoever. I actually think it's running a little smoother now too (greater atomization?), but maybe that's placebo.

And I really appreciate the help. I could send you a tip in reddcoins or something.

But thx

 

You're very welcome.I'm glad that worked out for you. Thank you for the update. Just give forward to help another person out with their setup.that's all I need anyone to do