S14 SR leaning out after battery drain. Help needed

[Bullett]

Like a dummy I left my lights on yesterday at work and it drained my batt. Well after jumping it, the engine would not shut off when I turned the key off, also the turbo timer had no power while every other component did. So after leaving the battery unhooked for about 10 min, I hooked it back up and everything was fine. Took it on a test drive and things were fine. This morning took it out and the wide band was reading at 13-14 at WOT. hasn't done that all week. My fuel pressure is at 41psi and low boost pressure is set at 9 psi. NO clue what changed. after draining my battery Mods are: factory T28, Wally 255, Tomei Type s afpr with gauge, stock injectors, stock maf, greddy Fmic, AEM Uego, profec B (9psi lo 13.5 hi), greddy turbo timer. The AFPR and injectors were installed just last weekend, but I have no leaks and pressure is good. What are everyone's thoughts?

[Bullett]

None of the great zivian minds care to chime in? Just turned my fuel pressure up to 41 with the vac connected. AFR is now bouncing between 13 and 17 at part throttle, sometimes coasts to 11, and at wot is only making it to 13.5 to 1. Fuel pump seem like the right direction?

[Kingtal0n]

what brand wideband

what is the voltage at the battery while the engine is running, and what is the voltage in the car by the wideband plug

[Bullett]

It's an aem uego. I'll have to throw the multi meter on it tomorrow. Do these cars get temperamental with anything less than 14v?

[anti tyler]

your gauge should only really see 14v with the car on... Maybe.. I mean thin about it. The battery is only meant to be charged up to 12.6V any voltage higher than that is put out by the alternator....

[G5SR20240]

Undo the battery once more and let it idle for 20 min. Wide bands have a life expectancy, most newer wide band gauges will allow you see the current health of the sensor. Let it warm up and calibrate to see if that helps at all.

[Kingtal0n]

Change your spark plugs

[Bullett]

Just put the plugs in last Friday. But I will check them and pull the battery again. Thanks for the input guys I'll update in a while.

[Bullett]

Anyone know how much psi a Wally 255 should put out unregulated? Mine is maxing at 44-5 ish

[Bullett]

Pulled the plugs and all but one were black and juicy .#4 was Casper white. Pretty obvious what the issue is now, I THINK. Should I get plugs while I'm at it? These are only two weeks old. I'm trying to upload pics but it's saying the files are too large.

[Kingtal0n]

unregulated it puts out 0psi

the regulator is what makes the pressure, the pump just provides volume.

pressure does not mean volume. as pressure goes up, volume drops. In other words, as your fuel pressure climbs, your available fuel feed (supply) dwindles.

This is one reason I always keep fuel pressure as low as possible. Another reason is, lower fuel pressure is less wear/tear on your fuel pump and, will help keep the fuel cooler too.


From the other side of the fence, higher fuel pressure might give better fuel injector atomization, leading to higher quality combustion and better fuel economy, and may help prevent misfires, especially when using large, inefficient injectors.

other things to try:
1. clean your maf hot-wire
2. check for vacuum leaks, especially after the maf but before the turbo
3. make sure the alternator is charging

[Bullett]

Btw alt is charging fine. Thinking it's an injector or coil

[Bullett]

Alight. voltage tested 12.4 off and 14 even running, changed out injector #4, fuel pressure is good (at idle anyway), maf and air filter have been cleaned and she's still reading lean. the Wideband is only a week old and I tested the sensor already. I'm at a complete loss now. about to go grab another set of TR55s and throw one of my other wallies in the tank and see if maybe that's the issue. Is there any way this could be an ECU issue caused by the power loss?

[G5SR20240]

Did you reset the battery and let the ecu become in a readiness state?

[Bullett]

Not quite picking up what your asking. Yes I unhooked the battery but not sure what you mean with the ecu

[Def]

Stock tune? That's perfectly normal AFR until about 5.5-6k rpm where it'll richen up a bit.


You should put some injectors, Z32 MAF and ecu on that thing. You'd add a solid 80-100 rwhp and have a safer tune.

[Bullett]

13.0 at WOT?? I mean when I do it its pulling fine and not breakup but those numbers seem pretty lean. yes its on a stock tune, and the only reason I haven't gotten a tune, maf and injectors is because I'm going to sell this set up pretty soon and just want to make sure there are no bugs in the system. I don't like to put crap out there with my name attached to it.

[Kingtal0n]

I think you found your problem, one cylinder is misfiring causing your wideband to show lean. verify spark, gap, (change your plugs), verify fuel, verify compression on that cylinder.


at the end of it all, make sure your narrowband oxygen sensor is working

All plugs should come out pretty white. the blackness is a problem. You probably have a boost leak.

[Bullett]

Got ya . I'll grab some plugs tomorrow. Gap is set at .30 currently

[Bullett]

Update: checked plugs and they are now all white, but looking over my I piping, noticed a pin sized hole in the weld for before the blow off valve. Hopefully that's the culprit. So I'll tig it up tomorrow and go from there.

[Def]

13:1 AFR at WOT and <6k RPM is normal for a stock tune at slightly higher boost. It's designed to run leaner in the midrange for emissions purposes (like almost every other car out there).

A misfiring cylinder under boost is VERY noticeable, and it does not feel like a smooth pull at all.

[Bullett]

Well so far I've checked compression (100 across the board cold), changed fuel pump, checked plugs, fixed minor fuel leak from filter, hunted down vac leaks (no test until tomorrow), and so far the wide band is still showing 14 and all the way to 17 @wot. the odd thing is its not breaking up. the idle is a little bubbly, but I'm assuming that's from my 39psi fuel pressure. Also I'm running an unrecirculated BOV only due to the fact I can't find hoses or piping long enough to reach the other side of the engine bay. Is it in any way Possible that I WOULDN"T feel this thing breaking up @WOT with an AFR of 17to 1???

[Kingtal0n]

Originally Posted by Bullett

Well so far I've checked compression (100 across the board cold), changed fuel pump, checked plugs, fixed minor fuel leak from filter, hunted down vac leaks (no test until tomorrow), and so far the wide band is still showing 14 and all the way to 17 @wot. the odd thing is its not breaking up. the idle is a little bubbly, but I'm assuming that's from my 39psi fuel pressure. Also I'm running an unrecirculated BOV only due to the fact I can't find hoses or piping long enough to reach the other side of the engine bay. Is it in any way Possible that I WOULDN"T feel this thing breaking up @WOT with an AFR of 17to 1???

Nah, they will run fine at 16 or 17:1. they just get hot and parts will melt, the rings will break, the deck will get eaten up from pinging, hot spots rear their ugly face, the valve seals might even take abuse and the surly the oil could break down under such severe conditions causing excessive cylinder wear.

In other words, do not run the engine like that unless you "fix" the problem.

Try making a boost leak to see if that richens it up. make sure you are running 7psi or less of boost. Check for exhaust leaks before the wideband, any O2 leaking into the exhaust the wideband will read leaner. try another maf hot-wire from a SOHC KA24DE engine (cheap and easy to find).

It could just be your fuel pump if the problem is consistent.

[Bullett]

just did a vac test and it checks out too. there was something I forgot to mention, on cold and sometimes warm starts, it cranks a while before it finally kicks over. this is what led me to buy the AFPR, wide band. boost locks at 10psi and stays so I'm sure I've nailed all the leaks. besides fuel pump (which I just switched out) what would keep this thing from starting normally? Is there any way to test the coils?

[Bullett]

Btw thanks for all the input gents. Hopefully this will be sorted out soon

[Kingtal0n]

there is an orange wire coming off the ecu called "start signal" it needs a sign from the ignition switch during cranking,.

it could also be a bad ECU.

furthermore, because you are reporting a lean issue which may have to do with fuel flow/prime and now you mention the slow starting, I think your next move should be to verify there is not a physical blockage in the fuel system. I would start by pulling the return line and priming the fuel system. fuel should come shooting out immediately all over the place (catch it in a bucket- be safe).

its a pretty quick and simple test and it is free. next I would try another ECU. Or check the plug at the CAS for corrosion.

[Bullett]

Should the gauge on my afpr be reading zero when the fuel pump primes before start up??

[Kingtal0n]

if you have no fuel pressure, how can fuel be injected when the injectors open?

[Bullett]

Ok. thought process was as long as the pump sent fuel, there would be a measurable pressure. Just when you think you know things, you go and buy a turbo car and get an education. . Checking those items you mentioned in the previous post tonight.

[Bullett]

So I pulled the return hose from the fpr and got nothing. Then I tried the return directly from the rail (bypassed the FPR) and could only get a few spurts.