still fuel cut

[deathburgr8]

i fixed my boost leak at the bottom of the IM which i thought was the reason for my fuel cut and only 7psi.... im all out of ideas here...my car wont boost stock 12psi and when i try to go WOT it will studder and it seems like it hits fuel cut....ANY IDEAS...Stock jdm 4g63 510cc injectors and sm 16g...

 

[steve]

Second... white plugs indicates lean, indeed.

White plugs mean hot, not necessarily lean. BPR6ES plugs in my car have always (since new) been white when I pull them because they run at the high end of their temp range and burn off all the deposits. Putting 7's in leave me with darker colored plugs but increased misses at idle.

These cars are computer controlled and spend a large part of their time in closed loop where the 14.7:1 average AFR also helps keep the plugs clean.

We have a strong ignition system and lots of heat under the hood. That's hard on plug wires.

Fuel cut tends to be pretty violent, some liken it to hitting a brick wall. If you ever have hit the rev limiter hard you have some idea, that sounds like you just dropped a valve. You'll see the ECU turn off the injectors if you log the car and the high airflow that triggered it.

Soft missing from bad plugs or wires tends to be more like a loss of power and a log won't show much abnormal.

 

[KKneipper]

Have you figured anything out yet? My brother was telling me how to read the code with a voltmeter. Seems like that would be the best way to start figuring out a solution.

 

[asb2106]

interesting read on this thread... Im having basically the same problem

The motor runs fine, i slowly rev up and it will build a few pounds of boost and be fine. But if I go WOT it builds up and as soon as it hits 7 or 8 pounds it chugs out, i back off, and it backfires.

I have replaced injectors, coils, ignition control module, plugs, wires, redone the head, intercooler piping, replaced turbo with e316g, new fuel pump, along with cams and a few other things.. and it does this. Now it did it before as well.

As it currently sits Im thinking its my MAF now. if you wanna read over my troubleshooting thread and a video of what mine was doing, check it out here -> 95 TSi not starting after making changes

it starts from way back but the more recent posts will give you all the new info.

here's a direct link to the video of my stutter / fuel cut / chug problem.. is this what yours is doing?
YouTube - video-2010-03-26-17-19-40

**EDIT
hehe, i like my "new member / lurker" status! nice

i almost feel a little relieved to find someone else with a similar problem, have you checked out your maf, tried another?

I'm putting a different maf in tommorow evening, Ill post results if it helps, or keep an eye on that thread at WiDSM..

 

[suprastar91]

bad grounds anyone!!!!!!!!!!

 

[deathburgr8]

yea man i tried another maf and no change im leaning towards coil packs now cause when its cold it will build the 7 pounds and not cut out and will eventually get up to 6000rpm when it warms up i cant go past about half throttle our it will cut out and when it does get past that point it will take me for ever to bring engine rpms up even goin down hill another thing i noticed was in neutral when i tried reving it uped it bogged hard.....?

 

[350war]

What is the CEL for? Do you still have a Cat. on it? Definitly read the codes before throwing money at it.

 

[asb2106]

Coolant Temp Sensor?

Are you running rich? can you smell gas out the exhaust?

 

[deathburgr8]

still has the cat i tried reading the engine codes with a voltomter but i couldnt figure that shit out ... to many numbers

 

[350war]

Possibly plugged cat? I know broken record but a logger with MMcd will read and clear DTC's. Check the classifieds I've seen them for $30-$40.

 

[deathburgr8]

well i made a test pipe and got rid of my cat today....now i can get 12psi to 14psi sometimes but im still getting fuel cut...and after doin some runs my car started missing turns out i melted my #2 spark plug...how and why

 

[350war]

Sounds like you are running lean. Next cheapest step is to change the fuel filter and rewire the fuel pump. You really shouldnt run hard without a logger. If your melting spark plugs you could also be doing damage to the piston or other internals.

 

[deathburgr8]

Well I got a boost gauge and found out the timing was all the advanced fixed the timing and now I get 10lbs and no fuel cut car feels slow though my friends talon with a 14b turbo just seems way faster.... Why? I have a bigger turbo and bigger injectors his is all the way stock..

 

[350war]

With the bigger turbo you will not spool as quickly. Can you turn up your boost more than 10 psi without it cutting out? You should be able to run 14 psi with no trouble. His boost is probably higher than 10. With the boost pressure solenoid restrictor removed I am running 14 psi on a 14b I think stock was 12-13 psi.

 

[deathburgr8]

i finalley got my code read and its 14 tps im also still getting fuel cut and only 10lbs would this be why

 

[350war]

Yes. Need to change the tps and adjust. With the tps bad or out of adjustment the ECU cannot see throttle position. This is probably whats causeing you to lean out.