So heres my long story... Scroll down for short version

Ever since I got my car tuned (While still at the tuners) the car would take longer than usual to start. It now takes about 10 cranks to turn over, I don't know if thats that real problem but its something to note. Also every once in awhile the car will start to crank and then a loud *DANT* sound would happen and the car would stop cranking. From my searching I assume its either my Spark plugs or my Injectors.

I had my car tuned with IK24 spark plugs (two setps colder .32 gap) that I bought from garage 1217. I think tuning with them may have caused their early failure. The week after I got tuned my A/F at idle was not longer 12.5-13.5 but 16.0 to --- (off the chart). I also noticed a much rougher idle than before ( idles around 650 rpms). I pulled my plugs and checked them and they were slightly black at the tip/threads. I cleaned them with a wire brush and re-installed them, but it didn't change their performance

Yesterday on my way to Formula drift my car ran like complete SH*T. As soon as we jumped on the freeway my car was throwing codes left and right. I got codes P2195, P0171, P0302, P0303, P0304. Then when I could go at partial throttle my A/F would go to 10.0 and stay there. Which means the car was most likely running much richer than 10.0 Once we got off the freeway the car stayed rich the whole time. At cruzing speeds, my A/F would be low 11's and drop into the 10's then into 10.0. before this day, I would be at around 14.5-15.5 at the same cruzing speeds.

When we got to the event, my car was bogging horribly and would just die. I ended up pushing the car into the show lol. I pulled my spark plugs out and they were COMPLETELY black, fouled out. I had no spare plugs so just drove home in the slow lane.

I stopped at Pep boys and picked up some Cheap NGK BKR6E copper plugs just so I can drive my car w/o problems. This morning I go to start my car and I got that loud "DANT" sound again and the cranking stopped. Which Made me assume that its caused by my injectors. Also my A/F at WOT is no longer in the 11's but very lows 10's. Can the plugs change my A/F ratio?

I am going to be buying new plugs, most likely NGK BKR7EIX. Does this sound like the plug for my set-up?

My setup:

Custom Equal length Manifold
Open Dump
4 psi
Garrett 60 Trim
ZPI 550 PNP injectors

For the TL;DR crowd...

1. Car makes "DANT" sound when starting every once in a while, I Dont know why
2. My A/F is Very rich now, into the 10's, Have no clue why
3. What are good plugs for my set-up

Thanks for your time

 

check for boost leaks, it'll cause super rich situations, also vac leaks. your plugs are fine, well not the fouled ones, but the part number. on 4 psi 550cc injectors are alittle extreme, might wanna grab some 440's unless you plan on turning the boost up, bigger the injector harder idle becomes.

if you find no boost or vac leaks it either tuning related or injector related

 

1.) My car takes the same time on start up and so does my friends turbo tc. While turning the key (not before), blip the throttle about twice it should start up a LOT better.

2.) Your car sounds like it has the same issues as mine (look up my thread about TT basik kit). After looking at your pictures it seems it may be your 3" intake. That was my problem and after switching to a 2.5" intake it helped the MAF read a lot better. The 3" intake doesnt allow the maf to get in the middle of the pipe and also has a low velocity. Try blowing into your air filter with your car on with your mouth really close and see if it affects idle if so than anything such as weather/radiator fans/blow off valve/wastegate could all be affecting your tune/AFR's. That is what ive been going through for two weeks now hopefully thats not what you have.

3.) The plugs you mentioned should do just fine. NGK 1-step colder. Your running 4psi so that should be fine.

 

it all happened with all of the sudden? should just stop driving your car till you find out what's going on. What management are you using? My afrs are going crazy too today, tried to load a different map and it idles 16-18 to unreadable super lean, loaded back the previous map and it still crazy lean even if i restart my ecu..

 

Im going to double check all my vac lines tomorrow. I also called my tuner to set-up an appointment if I cant fix the problem myself.

Im also upping my boost to 7 psi as soon as I figure out my problems

Ill try your suggestion tomorrow, hopefully I don't need to get a new intake made haha

Has anyone had that same starting problem as me, where it makes that "DANT" sound and the cranking stops?

Thanks for the quick answers guys. If anyone else Has any input feel free to post

 

Please post up what kind of EMS you're using, how it's wired, and what add-ons were used with the kit.

Are you using rubber couplers or threaded silicone couplers? Running 11.0 or richer for extended periods of time will skyrocket your EGTs. The high temps will add to the car feeling like it's bogging down.

We've been telling everyone the 3" MAF pipes are not suited for the tC at all. It screws up your MAF's ability to meter the air properly. The MAF is set to read certain velocities, then the ECU responds with preprogrammed fuel and igntion trims. If you use a 3" MAF pipe, the speed of air going through the pipe is slower. The result is less fuel and more agressive ignition. The tune will be off, causing the car to also run higher EGTS, and be more prone to knock.

Please post up in response to the Q's about the couplers and EMS. I would also recommend you run IK20s or 22s with only 4psi. IK24 is a little too cold.

 

Im using AEM F/IC w/ the Dezod PNP harness. With Silicone couplers

 

Have you been able to attach a laptop to the AEM FIC to see what corrections it's making to the ECU? I'd be curious to see what the numbers are on the fuel and ignition maps. You could always email me a screen shot of the maps if you like. joe@dezodwest.com

 

No, I don't have access to a laptop Thanks for the offer though

How big of an affect can the weather have on my tune? I just took my car out right now and it Idle perfect at around 13 but still rich at WOT

the past few days in So Cal have been HOT! and this is right when my car started to go super rich at WOT

 

Temps make a drastic difference, especially if you have too cold of a plug, and the wrong size MAF pipe.

It seems like you need to lean it out by quite a bit. If you send anything, I'll be happy to take a look at it. Let us know how it goes.

 

Update:

So yesterday my car felt great. I got into boost with my A/F at around 10.8-11.2 Still more rich than I would like but at least it was running well, at least for an hour.

About an hour into my drive around town, the same thing happened my A/F was at 10 and pinned there. No matter if I was cruzing with my foot off the gas or if I was WOT

I parked and pulled my plugs out (I carry my tools w/me lol), and they were completly Fouled. How can brand new plugs foul out so fast? they lasted 3 days

I already ordered my NGK BKR7E's, they should be here soon

I have an appointment with my tuner (Shawn at Church's) to double Check Everything, and check my tune.

I have check all my VAC lines, they are perfect. My car is throwing only one code P0171. Shawn suggested that it might be my 02 sensor(s), but wouldn't I be throwing a CEL code for them if they were busted?

Any input?

 

DTC P0171 Fuel Trim System Lean Bank 1

 

i have same code P0171 too that kept on coming back but too.. how is your idle afrs now? but in your case you are running rich so how can you get a lean code? does it play from 10 all the way to 17 up to --? i wouldnt think its your plugs being colder though since you are having problems even when not in WOT, when not in boost all plugs should function the same correct? hmm im curious about that stock o2 sensor though, keep us posted

 

my idle afrs depend on which plugs im using. Stock plugs I get around 12.5-14 at idle, which is good. But at WOT its mad rich

Using 2 step colder plugs my afrs at idle were 15 to --- which means its off the chart. At wot it was around 11.5-12, but once they fouled out it was pinned at 10

Then I tried some crappy copper plugs to just get me home and they were running ok for about 3 days then fouled out on my and my afrs was at 10 no matter if I was at idle or at WOT

Im seriusly thinking it is my primary 02 sensor. Also when my plugs foul out I get code P2195, meaning bank 1 sensor stuck lean or something close to that. But with fresh plugs the only code I see is P0171

 

so you are getting a 1 step colder plug right? i wonder if the different temp plugs affect idle afrs.. im running step 2 colder plugs and my idle is in the 15s too and at times goes 16s to -- .. I too have WOT afters like yours 14.4-12.. I might have same issue as you, except that i've never ran too rich

 

The coldness of the plug has to deal with the length of the spark plug and how quickly it ignites. Here is an illustration from NGK

Yes it will effect your air fuel ratio because it will effect your timing.

 

So in what way would a colder plug affect the afr? does it make it a lil bit lean, for instance like NVmyTC's example that his stocks idles 12.5-14 and crazy 10 rich at WOT on stock plugs but 15s up idle afr on step 2 colder and 11.5-12 at WOT which is more ideal.. This would then lead me to think that as you go higher in boost the colder the plug recommended so to keep the mixture from being too rich but on the other hand you would have to tune idle so it will not be too lean on the colder plug.. i know there are more important factors with tuning but im just using this as an example to see how colder plug affects the tune.. i might be wrong, so feel free to correct..

nvmytc- hope you dont consider this a threadjack

 

So I decided to jack my car up this morning and check my secondary 02 sensor, and I noticed that with the Antifoulder mod, the sensor was hitting this silver thing (no idea what it is) and caused one of the wires to become exposed.

I can assume this is what is causing the p0171 code, but can this really affect my A/F ratio?

 

Not sure but Bank 1 usually refers to the sensor on your header :o

 

long story short the stock plugs could stay too hot, hot enough to ignite the air/fuel mixture too early and cause pre-detonation, which is a bad thing. (carbon build up can do the same thing, the carbon can get so hot that it would ignite the air/fuel mix early causing pre-detonation or pinging). Also, I take it as since the plug closer to the hot range can heat up faster, it can also fire earlier. Which is why it is recommended to go colder plugs to prevent too early of a detonation and so the plug isn't getting so hot that it ignites the a/f mix before its intended. I repeated myself a lot lol...