Unable to rev after single turbo setup with Apexi PFC
 

Hi All,

As the title states I am currently having an issue trying to rev the car passed 2.5-2.8k since I upgraded to a single turbo setup. I'm aware of the multiple threads on this forum and many others relating to the infamous 3k hesitation issue but mine seems to be a little different especially since I have an Apexi PowerFC.

With regards to modifcations, I removed all of the stock TT bits and replaced with an XS Power turbo, manifold, V Mount rad/IC setup, battery relocation, WG and BOV, removed ISC, double butterfly and other bits on the UIM that aren't needed(I picked up all the Banzai racing blanking plates, which helped identify what to remove). I've retained my stock fuel setup (for now, was a little nervous to change all in one go, I'm aware of the resistor issue on pump and the FPD fire issues.. trying to get the car going in stages, sorry!). The car was bone stock prior to embarking on the single turbo route and I had the Apexi PowerFC installed back then, I was able to rev freely with it and drive around without an issue before going single turbo.

Here's what I've tried as per multiple thread "fixes"

1. Added additional ground - 2 x 8 gauge in front and 2 x 8 gauge in rear where Battery is. I see 12.7v+- while testing random ground points in engine bay, inside car and boost (14.4v when car is idling)
2. Swapped new plugs 7's and 9's
3. Swapped leads with my other bone stock FD
4. Replaced fuel filter
5. Checked inside fuel tank for gunk. Looks brand new inside
6. Reset PFC back to factory 6.07 dat file and did "wargasm" single turbo changes. Car wouldn't start, assuming cranking fuel too high on base map? (2.8k rev issue was on a previous single turbo map. car started no problems)
7. Have had a friend (YouTuber called Beytek who tunes FD's) make me a custom MAP which I am yet to test (Made it tonight so haven't had a chance)
8. Have checked all vacuum leads, all brand new and in correct places.

One unfortunate problem is that I don't have a downpipe on the car yet, as I've built the whole thing in my garage. I was hoping to have it running so that I could drive it up the driveway and onto a flat bed truck to go to get the DP and exhaust done. This means I have NO wideband connected right now so cannot see AFR's unfortunately.

Below video of my startup issues. The initial very smokey bit was due to vacuum line being off MAP, but once that was resolved things didn't go well with revving. I'm aware my VTA1 and 2 are slightly off but within range afaik.


Sorry for the mass amount of information, just figured I would be upfront and try give you all everything so that I can get a helping hand. Last thing to add, I started the car +- 4 months ago during the early stages of the single turbo build and it didn't want to rev passed 2.8k then either but I ignored that fact as I thought it was something else.

Hoping someone can point me in the right direction.

Thanks in advance

Nelson

Whats up Nelson?
What ignition system do you have?

Hey Red!

Thanks for the reply, ignition system is 100% stock. I haven't swapped anything other than IC/WG/BOV/Turbo/Manifold/Radiator. Utilizing the standard harness and all required sensors, didn't touch or unplug any fuel wires or ignition wires during the build. I'm really stumped!

EDIT: Just to add, my heat warning light on the dash is constantly on now.. I believe the PFC uses that as a knock warning lamp? Could just be on from my lumpy idle causing knock?

Oviously , dont drive the car.
The light sensor might be bad if it come on right when you start the car.
Could be clogged cat if you still have it. I know some cats melt the inside when get converted to single, maybe mine was old.
You may have a bad fuel/air ratio.
On a single turbo, the stock ignition system might break up. You will need some amplifier like hks tween power or beter coils.

I found some info here :

https://www.google.com/url?sa=t&sour...MzdCt2mLo1THeY

Definitely not the cat being clogged up as I have no exhaust at all.. Trying to get it running so I can get it out my driveway and onto a flatbed to go make an exhaust at a shop..




Could be the ignition system but there are tons of single turbo FD's around with the stock system in place :(

I have a JDM FD and a Power FC. I believe the light will flash when you are getting over threshold knock, or close to maxing injector duty. If you have a steady light from start up then it is likely missing feedback from a sensor that it is expecting to see. Go to the sensor check screen on the commander and check those. If you need you can post a picture of it here and we can help.

Start simple, no need to worry about upgrading ignition at this point.

Thanks for the response, my sensors are displayed in the above video at 5m24sec if you want to see the values moving live and also hear what the car sounds like, VTA values are slightly off and need to be adjusted on those screws by TPS.. Attached screenshot from video

I agree on not rushing into replacing parts just yet, as it worked 100% fine prior to the upgrade
https://cimg3.ibsrv.net/gimg/www.rx7...4a4c50d7ee.png

Something to add.. Just had this piece of advice come from one of my subscribers. Looks like he's had the same issue and managed to fix it.

​​​​​​​
https://cimg4.ibsrv.net/gimg/www.rx7...6d9a287a3c.png

See if you can adjust the TPS within spec and then get back with us http://haywire.nu/rx7/How%20To%20Che...20FD%20RX7.pdf

Thanks for that link, will give it a bash on Saturday. Will make for some good YouTube content too. Will let you all know