Cutting Out Problems.. Falls Flat

[zchdrl]

The car is a 95 S14 with S13 SR

I've been having this problem since the rebuild where the car will fall flat on its face at 3500 in second gear. Third gear it's 2200 so it's load dependent. In first gear I can get up to 6k. It idles fine, boosts up fine, it just cuts out.

Things I have done

Checked for boost leaks-None
Replaced MAFS
Replaced CAS-Put a oscope to the old one and the 180 degree signal wasn't there

Any help is appreciated, thanks!

[zchdrl]

It's also worth to mention it won't go past 30mph

[zchdrl]

https://vimeo.com/108976068

[jscherf92]

Check the ECU for codes? sounds a bit like limp mode except for that 1st gear rpm peak.

[zchdrl]

Check the ECU for codes? sounds a bit like limp mode except for that 1st gear rpm peak.


It throws code 11 and 12

[bmxer882x]

I know 11 is spark related. I just had that and was actually sold a broken one so I had to get another. Did you buy a used or new one?

[zchdrl]

I know 11 is spark related. I just had that and was actually sold a broken one so I had to get another. Did you buy a used or new one?


Code 11 is for the CAS. I got a used one, I'll be going back to Airlift to use their oscope to check out this one. Also should mention that the ECU is fine too. I borrowed their shop 240 ECU and it ran the same

[Kingtal0n]

check the ground for the coilpacks is installed to the back of the head.

then put some new plugs in it. run only 7psi of boost with even a stock gap and see what happens.

[zchdrl]

check the ground for the coilpacks is installed to the back of the head.

then put some new plugs in it. run only 7psi of boost with even a stock gap and see what happens.


Just redid that ground today. I have the Chasebays harness by the way if that matters. The plugs are NGK BKR7E VPower gapped to .30 that are relatively new. Ill try to adjust the amount of boost it's pushing but I'm not really sure how to do that. It boosts up to 18psi fine in 1st gear if that says anything

[bmxer882x]

U boost the t25 up to 18 psi?

[zchdrl]

U boost the t25 up to 18 psi?


No I'm running a gt28

[bmxer882x]

What maf are you running? If it's stock sr your could be maxing it out.

[zchdrl]

What maf are you running? If it's stock sr your could be maxing it out.

I was running the stock maf before the rebuild with no issues now I'm using a ka24e maf

[Loomis112]

Are you running an AFC of any kind?

[zchdrl]

Are you running an AFC of any kind?


Yes apexi safc

[Loomis112]

What kind of maf and what are you in and out settings?

[zchdrl]

What kind of maf and what are you in and out settings?


Reman ka24e maf 6in 6out

[ultimateirving]

Sounds like coil packs from the description. But after seeing you're running an safc, it's possible you're running super lean too and with 18psi? Don't count on having the engine last

[zchdrl]

Sounds like coil packs from the description. But after seeing you're running an safc, it's possible you're running super lean too and with 18psi? Don't count on having the engine last


I'll try to borrow a set on Monday to see if it's the coilpacks anybody have bad fuel pumps that match the description?

[bmxer882x]

Has the car always ran with this setup and it just started acting funny or did u recently change anything? Sounds to me like you maxed the maf out.

Try running lower boost and see if you can boost through all gears.

Either way I would recommend getting a z32 maf

[zchdrl]

Has the car always ran with this setup and it just started acting funny or did u recently change anything? Sounds to me like you maxed the maf out.

Try running lower boost and see if you can boost through all gears.

Either way I would recommend getting a z32 maf


It was rebuilt. Same setup as before. Only thing different was the SR MAF but I've heard the SR and ka24e MAF are the same

[bmxer882x]

Yeah they work interchangeably as long as u swap connectors. I know from experience.

[zchdrl]

Something I've noticed today is when I'm revving it in neutral slowly it will miss or cut out at 3500rpm. It won't happen if I rev it fast though. So I'm guessing it's rev dependent and not load dependent

[Kingtal0n]

Something I've noticed today is when I'm revving it in neutral slowly it will miss or cut out at 3500rpm. It won't happen if I rev it fast though. So I'm guessing it's rev dependent and not load dependent

try a different maf

[tyson2699]

heyy i just contacted you a few days ago because i saw your car on craigslist. nice car btw good luck figuring it out!

[bmxer882x]

try a different maf
This. I recommended it earlier. Get a z32 one. Either way you have to be close to maxing it out if yours is good then the upgrade was still worth it.

[zchdrl]

try a different maf


Try a SR maf?

[zchdrl]

heyy i just contacted you a few days ago because i saw your car on craigslist. nice car btw good luck figuring it out!


Thanks bro!

[zchdrl]

This. I recommended it earlier. Get a z32 one. Either way you have to be close to maxing it out if yours is good then the upgrade was still worth it.


I'll try to borrow one from a friend

[zchdrl]

Forgot to mention code 12 for the maf went away now it's switching between code 11 and a solid red light

[zchdrl]

And occasionally I get code 55

[zchdrl]

When I wire the maf input wire directly to the ecu and bypass the wiring for the safc it runs a lot better. Evidence that the maf is bad? Lmk guys

[ultimateirving]

The safc is the bad link. I wouldn't run that in any car because they aren't a reliable way of tuning.

[zchdrl]

The safc is the bad link. I wouldn't run that in any car because they aren't a reliable way of tuning.


So take out the safc, order a standalone, and get it tuned will solve my problems?

[ultimateirving]

So take out the safc, order a standalone, and get it tuned will solve my problems?

Start wit taking out the safc and rewiring everything the way it should be pre-safc.
Then you will need either a standalone or a rom tuned Ecu to accommodate your modifications. And you will have more power and better reliability

Ps the stock maf/ sohc maf could also be maxing out if you're hitting 18psi. You need a z32 maf if you really intend to make much more than 250-280 hp

[bmxer882x]

Are u running larger injectors or stock? If stock run on the stock ecu and set the boost around 12-14 and u would be good until you could get a tune. After tune you would be safe to bump it back up to 18

[zchdrl]

Start wit taking out the safc and rewiring everything the way it should be pre-safc.
Then you will need either a standalone or a rom tuned Ecu to accommodate your modifications. And you will have more power and better reliability

Ps the stock maf/ sohc maf could also be maxing out if you're hitting 18psi. You need a z32 maf if you really intend to make much more than 250-280 hp


I'll be doing that as soon as this problem is fixed

[zchdrl]

Are u running larger injectors or stock? If stock run on the stock ecu and set the boost around 12-14 and u would be good until you could get a tune. After tune you would be safe to bump it back up to 18


Stock injectors

[bmxer882x]

Yeah then if a maf switch doesn't fix it or you don't try that, try ditching the safc and run stock and see how it runs.

If you get a z32 maf it will not work with stock ecu. Without a standalone or rom tune so if you ditch the safc run stock maf

[zchdrl]

Yeah then if a maf switch doesn't fix it or you don't try that, try ditching the safc and run stock and see how it runs.

If you get a z32 maf it will not work with stock ecu. Without a standalone or rom tune so if you ditch the safc run stock maf


This setup worked perfectly fine before the rebuild, something failed

[bmxer882x]

Safc isn't a safe way to run large amounts of boost reguardless. It only adds extra fuel when needed. Timing is nkt affected at all so things could go bad very quickly. So if the fault is in it or if it isn't either way it's a win win

[zchdrl]

Safc isn't a safe way to run large amounts of boost reguardless. It only adds extra fuel when needed. Timing is nkt affected at all so things could go bad very quickly. So if the fault is in it or if it isn't either way it's a win win


It runs better but still cuts out with the ecu wired direct

[zchdrl]

I'm getting closer but the problem is still there. The CAS tested out fine with the oscope. MAF is fine. Coilpacks are fine all the wiring is fine. The only thing left is the VSS. I'm going to install more grounds and check the wiring for the VSS and possibly install a new sensor. Has anybody had a weird cut from a vehicle speed sensor? It's almost like the ECU says fuck no I don't know what speed I'm at and shuts the injectors off and it goes full lean

[bmxer882x]

Check your injector grounds. Clean them up.

[zchdrl]

Check your injector grounds. Clean them up.


That's already been done. I'm going to add a ground from the intake to the chassis and maybe one from the back of the head to the chassis. But I'm really thinking it's the speed sensor that's the only thing that doesn't work that use to

[ultimateirving]

Ok since you bypassed the safc and rewired the maf that's good.
Something I have had personal issues with was my coilpacks. It started small, I could drive and cruise around no problem, but when I would go WOT, it started to cut out in the high rpms. It ended up being a bad coilpack that fired under normal driving. But didn't under boost.

[bmxer882x]

My speed sensor is unhooked and car runs.

I have the stock ground on the motor plus one from the intake. Give it a shot let us know.

[ultimateirving]

My speed sensor is unhooked and car runs.

I have the stock ground on the motor plus one from the intake. Give it a shot let us know.

Speed sensor doesn't do anything. I don't have one at all since I'm using a z33 trans.

[zchdrl]

My speed sensor is unhooked and car runs.

I have the stock ground on the motor plus one from the intake. Give it a shot let us know.


It's got to be the chassis harness I'm using then. I had to swap one from another car

[fthst]

Check the ECU for codes? sounds a bit like limp mode except for that 1st gear rpm peak. http://financede.com/apple/images/40.gif

[zchdrl]

PROBLEM FIXED ending up being my power wires going to the fusebox were wired wrong. Car runs fine now. Crazy how something so simple created that big of a problem. Huge thanks for everyone who helped me out

[ultimateirving]

Glad to hear man. Thanks for letting us know the problem too. Help future Zilvians