That doesn't sound like a good thing to use right over the exhaust manifold

 

bro just do it. criminy sakes. its just a test. i had zip ties on my na for 2 years and it was fine.

 

S5 aux ports work opposite compared to S4. He needs to wire them out instead of in which can be a pain to setup on s5. I zip tired my aux ports open on my s4 for years and the zip ties never snapped. If your concerned about it then use some metal wire.

If your ports arent opening then that could be the reason for sluggish top end although your last video didnt seems to sluggish for an n.a

 

I've been looking at solving my high rpm hesitation issue more than fixing the sluggish acceleration. I looked at my TPS again and checking the resistance, i found that my multimeter reads .0L right before being fully open. I assume that this means that the TPS is faulty right? I changed the TPS with another one I bought from someone on this board, however it does the same exact thing. It reads .0L right before being fully open.

Also while checking the resitence, I noticed that i couldn't get a steady reading of 1K ohms at idle. I could get it to 1.005k, but when I open the throttle and close it again, often times i'd get a different reading. (does this on both TPS i have)

 

Have you check your main grounds?

 

Yup, checked all the major grounds listed on Aaroncake's website, except my S5 didn't have the grounding block under the trailing coil like his is mentioned. I only had a single grounding point.

 

Well, I think I've narrowed it down to the TPS. I unplugged the tps and didn't notice a weird idle surge (i have another thread about it), and the idle seemed to be somewhat more steady, and not fluctuating while hitting the gas. It was just a short drive to get lunch, so i'll be checking it again on my drive home.

 

Tried another brand new TPS, as well as a new ECU. I'm still getting the high rpm hesitation.

The new ECU did however clear code 33.

 

Put some grease on the 56 port actuators and see if they're opening or not. If they opeb you should see it marked on the grease

 

I ended up taking the car to lucky 7 today.

Turns out the hesitation is from the car running pig rich after 5200rpm, and the lack of top end power was from the VDI being stuck closed.

Apparently there was some debris stuck in the hard line leading to the VDI solenoid, so that the VDI would not open.

They threw the car on the dyno, i'll upload the video and dyno graphs tomorrow. Right at around 5200rpm, the AFR's drop to about 10:1, and hold there till redline. What would cause something like this? Leaky injectors?

 

Could be secondary ports not opening. Still dumping the fuel, but not getting the extra air...

could be afm.

could be in limp mode

could be plugged exhaust. i had a cat that was 90% clogged on my old NA.
\
could be a lot of things

 

Ok, now that I've slept and can actually write, here is what went down at Lucky7.

I emailed Fris and had informed him that my car is feeling a bit sluggish, was having a high RPM hesitation that kind of felt like a fuel cut, as well as a funky idle that couldn't make up it's mind.

After dropping it off, I received a call shortly after, asking if it was OK to throw my car on the dyno so they could get some diagnostics. I told them to go ahead, as a couple of my friends had suggested I dyno the car to get AFR's, and I was really curious about the power that the car was making.

A few hours later I get another call, telling me that they figure out that the VDI wasn't functioning, and that they were going to figure out why. Louie told me that the car had made a whopping 108whp in it's initial baseline. I took the car to Buttonwillow like this, and I can definitely see why the car was 7 seconds slower than my girlfriend's miata(Me driving of course). They had wired the VDI open, and the car had made 138whp, however the car was running quite rich above 5000rpm. I do want to mention that the car only has an Apexi filter, Atkins 6port sleeves(I think) and a RB downpipe and presilencer. Stock header and exhaust.

When I got back to Lucky7, Louie told me that some debris had clogged the hard line coming off of the VDI solenoid. They cleaned out the hardline and replaced the solenoid and now my VDI was functioning properly. However, the car is still running pig rich above 5000rpm. Louie mentioned that the secondary injectors could be leaking. I have paperwork that the injectors were cleaned about 2 years ago, but I believe the car did sit for quite some time before I came into ownership.

Anywho, I attached both my before and after dynos. I'm still waiting to get the video from Lucky7, and I'll post that as well.

 

I decided to check if the car had any codes just for the hell of it during my lunch. I didn't turn on the car, just checked it cold.

Code 12: Full range TPS

Code 13: Pressure sensor (its back)


I wonder what it could be now. I installed a BRAND NEW TPS from Mazdaspeed last Friday, and the MAP sensor was replaced with another one I purchased off someone on this forum, which caused the code to go away.

I also changed the ECU for the hell of it before taking it over to Lucky 7, but didn't have any additional codes when I changed it.

 

Which ecu did you use?

 

Another N351 ecu purchased off someone on this forum

 

not sure if it makes a difference, but thats a vert ecu

 

According to FC3Spro, N351 should be a fed coupe ecu.

 

Take a look at the dyno chart comparison between stock S5 NA and a tuned Rtek.
It shows a similar AFR change + power drop at high RPM.
I don't recall if there is a fix for this without switching to a programmable ECU but it's something.
Rtek7 ECU Upgrade Detailed Information

 

Just wanted to conclude on this.

By the recommendation of the guys over at Lucky 7, I sent off a set of injectors to get cleaned by RC Engineering, and had them installed with new o rings . The car no longer has the high RPM hesitation and runs great now.

 

All in a day(s)!

 

And thank you to all who helped and pointed me in the right direction!

 

False Alarm!

Seems like my idle issues all came back shortly after having the injectors cleaned and installed. Once again the idle is surging, but only when the engine is warming up from a dead cold (3-4 minutes warming up, then stops surging after 6 minutes), and I'm having idle hanging again. Same. Exact. Issues as my initial post, except my top end power does seem to still be there.

 

Vacuum leak, BAC, or something sticking in the TB.

 

There are obviously different possibilities, but one of them might be the reinstalling of the injectors could have caused a small vacuum leak which stops once the engine is warmed up. Also, w/the injectors being cleaned they could be injecting more fuel than before cleaning and that 'might' be the cause of your issue. Another thing to look at is the double throttle diaphragm.

 

I've been spraying carb cleaner on the vacuum lines to see if I could find one, but can't seem to find a leak. Maybe i'm doing this wrong. lol.

I also noticed that when the car is idling high, I can hear a hissing noise coming from around the rat's nest area. I can't hear it when the car is idling at 750rpm.


I'll look around more at lunch. But what should I be looking at specifically with the double throttle diaphram?