Please Help, New KA-T running very rich

[240_newb]

Hey everybody! Ive been a lurker here for a while and have used a ton of information from this site to help me put together my first turbo ever. Well it all went pretty smoothly, and ive somehow turned a perfectly running s13 hatch ka24de into a stumbling coughing mess! The car ran perfectly before being turboed, and now ive got a very rich condition, my wideband reads full 10.0 in boost and 13.4-14.5 idle. It will sputter up until 4.5-5k rpm and idles very rough, ive got so much black smoke coming out the back it looks like a diesel rolling coal! So ive come to seek the knowledge of those more versed in turbo setups than I. My setup is
sr t25 turbo stock wastegate 7psi
ssac exhaust manifold
sr 370cc injectors
remanufactured z32 maf
cxracing giant fmic with knock off bov
walbro 255
enthalpy ecu for t25/t28 370s and z32 maf
bkr6e plugs gapped to .035
for the egr i bought a block off plate but havent deleted it yet, just cut and capped the hardline to exhaust
charcoal canister delete
battery relocated to trunk

Some things i have already tried: a new ecu, same results as before, checked maf voltages, (.5 key on, 1.15 at idle) checked fuel pressure, (37 psi at idle, 45 psi key on) pulled fuel rail and had a friend turn the key to check for leaky o rings, no leaks found, boost leak tested 3 times, found a couple small leaks and fixed them but no difference. Verified timing is at 20 degrees.
Im just at a loss as to why its running so rich. It almost seems like a boost leak, but im still a little rich at idle, im going to try tightening the bov some and see if it helps, though its not leaking at idle. Ecu is not showing any codes, and i know its not the tune as I had martin send me a second ecu. Any help would be greatly appreciated, i cant wait to drive my car again, what was supposed to be a 3 day install has taken almost a month :|

[anti tyler]

First off what do you mean new ecu, did you swap it with an ecu that was tuned for your exact same engine setup? Is that what you meant at the end?


I know you're saying MAFs voltages are good, but are you checking the pins on the ECU plug? I had a similar issue but it was with pins slipping out of the harness at the ECU.

What guide did you follow on the Z32 airflow sensor wire up?

Have you compression tested it since the swap?

Have you pulled the plugs and looked at the piston tops?

[KAT-PWR]

How are you boost leak testing?

You are sure of your injector size? Check the coolant temp sensor resistance according to FSM

Bring gap down to .028

[240_newb]

By new ecu i mean i had martin at rs enthalpy send me a swcond ecu that was tuned for my setup, with that ecu it runs identical to the first tuned ecu so i am assuming the tune is not the problem. i checked the maf voltage at rhe maf, at the ecu and i verified it with my consult cable. I used the JWT z32 maf wiring diagram and ran both grounds from the pigtail to the ka harness ground. all connections were soldered and have heat shrink. compression is 163 across all 4, tested multiple times before and after swap. I blew a head gasket trying to diagnose it after about 10 miles and the pistons had a very slight later of carbon that wiped right off, head is back on with a fel pro gasket and arp head studs torqued to 70 ft lbs. The coolant temp sensor is new and appears to give an accurate reading over consult. I am boost leak testing by blocking off the turbo inlet and pressurizing the intake via the brake booster line to 10-20psi. Could the o2 sensor cause it to run this bad? i dont get an o2 reading through consult on the tuned ecu, but i do get one on the stock ecu.

[KAT-PWR]

Boost leak test from compressor inlet.

[240_newb]

Boost leak test from compressor inlet.

Ok, ill try that. Is there any difference to testing from there besides the brake booster being included? i know the booster holds vaccum for a long time after shutting of the engine.

[FaLKoN240]

Get another Z32 maf. A used working one from the junkyard.

I blew my first S14 KA on my first KA-T with a setup exactly like yours using a bum Z32 Maf

[EnnEssEnnKAT]

Is there a solid way to tell if it's bad or do you sort of have to figure that out via nistune and checking voltages to/from the maf? Good luck man

Sent from mTalk

[240_newb]

Well I tested for leaks and found a tiny one on the air regulator, got it sealed up and no difference. I'm looking for an oem z32 maf just to rule that out, there are no 300zx cars in any junkyard near me. I got new plug wires as my other ones were in bad shape, no difference. Cleaned the rotor and cap. Ive noticed that if I unplug the tps it will idle worse but has better throttle response. Checked the tps and it still reads .48 when closed and slowly and properly raises to max voltage (can't remember exactly number but it's working correctly) only thing I can do that makes it run better is add a lot of unmetered air, or take the maf off and press it half on, half off the intake pipe. Seems to idle much better like this and has better throttle response. Also I noticed that cylinders 3 and 4 seem to have a far lesser effect when I pull the wire or injector than cylinders 1 and 2, like it's running on 2 cylinders. Also all 4 plugs are a dry sooty black but cylinders 1 and 2 are tan on the ground electrode. I have tried switching the injectors 1,2 with 3,4 and there was no difference. Plugs and wires are new, egr is deleted. I dont know why they would burn unevenly. Maybe the cas is halfway faulty? Is there a way to test it?

[KAT-PWR]

That sounds like two bad injectors then.

[240_newb]

That sounds like two bad injectors then.

I does, but I swapped those two injectors with the front two, and cylinder 3 and 4 were still running badly. The injectors were good when the sr was pulled.

[NiSilS14]

separate the grounds on z32 maf wiring. jwt's instructions for z32 to s13/14 is known to run rich with both grounds to ecu. Refering to jwt's wiring instructions, C ground goes to chassis D ground goes to ecu ground.

[240_newb]

I'm pretty sure I read a post where they took apart a z32 maf and c and d were connected together inside. Well I tried running them separate anyways. Didn't help at all.

[NiSilS14]

One of my cars ran really rich with combined grounds, It's documented that jwt's instruction can cause them to run rich. Faulty MAF, CTS or knock sensor are usual suspects in a rough running car. Reminds me of a friend's car I helped with, swore up and down he had a good maf, even though that ended up being the culprit. Best of luck!

[240_newb]

Sorry if my post came off a little rude/standoffish. I really appreciate the help alot, you guys give me things to think about that I hadn't even considered. I'm willing to try just about anything at this point! I need to find another maf, as I got this one used and never actually saw it run on a car even though it seems to read right. I am throwing a code for knock sensor but I assumed it was an effect of the car running rich not a cause, i just replaced the sensor itself, but the harness may be bad. I'm going to try the resistor trick tomorrow and continue the search for a maf at a decent price. Looking to spend 50-60 if yall have one. :naughty:

[NiSilS14]

Sorry if my post came off a little rude/standoffish. I really appreciate the help alot, you guys give me things to think about that I hadn't even considered. I'm willing to try just about anything at this point! I need to find another maf, as I got this one used and never actually saw it run on a car even though it seems to read right. I am throwing a code for knock sensor but I assumed it was an effect of the car running rich not a cause, i just replaced the sensor itself, but the harness may be bad. I'm going to try the resistor trick tomorrow and continue the search for a maf at a decent price. Looking to spend 50-60 if yall have one. :naughty:

Not at all, try car-part.com it networks all the all junkyards around you. I usually am able to find easily, but it's been a while for me so N62s might be getting harder to find nowadays

[240_newb]

Well, I bought a used oem z32 maf and it still runs the same. For some reason its still running poorly on cylinders 3 and 4. I'm going to noid light test and make sure the injectors are getting proper power, then I may get a new distributor. The injectors all ohm out right and seem to be working. Maybe some wiring is bad? At this point everything is suspect, even parts that were previously working fine.

[NiSilS14]

That's too bad, it does sound like a wiring problem. Maybe test the harness for continuity from the injector connectors to ecm connector. Other than that, retrace your steps and see if anything looks incorrect.

[240_newb]

I FIXED IT!!! Turns out injector 3 I guess wasn't getting a good ground, and the previous owner spiced the ground for injectors 3 and 4 together. I don't know why it was running so well n/a like that... very odd. It idles very well now that it's running on all 4, but ive got sluggish throttle response and im throwing code 11 for the cas. I unplugged the tps and response and power improved, wich leads me to believe the cas may be bad, but im going to go over all the wiring first to be sure before I buy a dizzy.

[FaLKoN240]

Yessssssss good to hear!

[240_newb]

I know right! It was definitely on the back burner for a while and really aggravating me, im so happy I got it mostly figured out! I've got a used distributor on the way, figured I'd get it because it's basically free minus the cost of shipping, and I'm going to check the wires in the meantime, because even though it runs much better, its got hardly any more power, maybe less than n/a.

[240_newb]

Ok so just a couple more questions for yall, since I've had the car, the distributor has had to be all the way clockwise to get it to 20 degrees of timing. I know this isn't right, but, would that cause a large lack of power? could that be caused by the lower timing chain being off a tooth? The previous owners mechanic was shit and quite a few things were done wrong on this car when I got it. I'm also throwing a knock sensor code, even though I replaced the knock sensor recently, and that got rid of the code, doubt the harness is bad but ill check, could code 34 just be caused by timing being off?

[di-devol]

Double check the wiring for the knock sensor. Wouldn't hurt to re-stab the dizzy.