Sudden Lean Problem, No Boost Leaks

[JOLTY TacoMan]

Car was running great. 16g, 1000cc injectors, 255 fuel pump, e85, 25psi. Car suddenly began to run lean, turns out vac line for egr came off and the egr was stuck open. Fixed the vac line and drove it for another few nights. Now the car is suddenly running very lean again. Idles in the high 15's to low 16's on the wideband. No boost leaks and already checked the injectors for e85 build up. What else could cause this issue?

 

[Jmmahon]

Have you done any tuning lately? Pushing more boost?

 

[JOLTY TacoMan]

Nope, nothing has changed on the car in months.

 

[JOLTY TacoMan]

Small update, still having this issue.
So far I have checked
-fuel pump for e85 goo
-injectors for e85 goo
-fuel pressure
-fuel pump voltage
-main grounds
-injectors resistance

 

[ErikTande]

Wouldn't boost leaks cause the car to run rich? I'm not sure, just asking.

 

[kenuwine4g63]

Fuel filter perhaps?

 

[JOLTY TacoMan]

A boost/vac leak would cause the car to run lean under idle and cruise since it would be pulling in umetered air and rich at wot or most conditions in boost. I checked fuel pressure after the filter and it was good so its not the filter.

If I go to test the reading from the injector plugs with a multimeter what kind of numbers would I be looking for?

 

[Zufelt]

A boost/vac leak would cause the car to run lean under idle and cruise since it would be pulling in umetered air and rich at wot or most conditions in boost. I checked fuel pressure after the filter and it was good so its not the filter.

If I go to test the reading from the injector plugs with a multimeter what kind of numbers would I be looking for?

Do you have link? If so you have the option of killing one injector at a time and seeing if your idle changes to ensure that each one is working properly. If not then your still able to disconnect them one by one inside of your engine bay.

 

[Zufelt]

Double Post

 

[Phantom DSM]

A boost/vac leak would cause the car to run lean under idle and cruise since it would be pulling in umetered air and rich at wot or most conditions in boost. I checked fuel pressure after the filter and it was good so its not the filter.

If I go to test the reading from the injector plugs with a multimeter what kind of numbers would I be looking for?

With the key to on, you will be looking for voltage at one of the pins on the connector with one probe and the other probe to a good ground, you should get sually close to 12v

 

[Dsmkauai]

What 16g are you running? Also check your vac lines again sounds like you blew one off, possible for the fpr?

 

[JOLTY TacoMan]

Small 16g, extremely minimal shaft play. No vac lines have blown off, I have done like 20 boost leak test since this issue has happened

 

[bryanwheat]

Are you sure that the egr isn't still stuck open? Also you might look into the fuel pump o ring.

 

[Dsmkauai]

The reason I ask is that turbo does not like to be over 22psi! 25psi is just asking for trouble!! I suggest turning the boost down to 20psi and tuning around that. If not your turbo isn't going to last long at all trust me I know ! I was able to flow 37lb/min at 20psi out of mine and they are rated for 35lb/min. I think part of your problem is your turbo is out of juice at 25psi and is effecting your tune! What wastgate setup are you running? What turbine housing?

 

[JOLTY TacoMan]

Are you sure that the egr isn't still stuck open? Also you might look into the fuel pump o ring.

I'm getting full fuel pressure so I can't see how that would be an issue.

Just checked the voltage on each injector plug with the car in "on" and not running. Every plug 1 pin was 11.3 and one pin was 11.77.

Im sure the EGR isnt still sticking open because there is no air flowing out my exhaust like it was doing before. The only reason it was open before is because the vac line for the egr popped off and that line is now reattached and zip tied.

The reason I ask is that turbo does not like to be over 22psi! 25psi is just asking for trouble!! I suggest turning the boost down to 20psi and tuning around that. If not your turbo isn't going to last long at all trust me I know ! I was able to flow 37lb/min at 20psi out of mine and they are rated for 35lb/min. I think part of your problem is your turbo is out of juice at 25psi and is effecting your tune! What wastgate setup are you running? What turbine housing?

Trust me its doing fine on 25lbs, with some room to grow to. Been running 25 for a while now and will be going to 30 once I have a daily. I'm not sure how that is relevant regardless considering it runs lean in all conditions.

 

[elguareali]

I'm having The same Problem with my gsx (evo 8 ECU and SD) did you figure out what was The Problem? How did you solve it? Thanks for your reply
It's driving me crazy
I've replaced almost every sensor, checked and tested every wire and nothing

 

[Dsmkauai]

Good luck running 25psi and higher for to long on a small 16g. Way over its efficiency range are you sure its a small 16g and not a evo3 16g? What airflow you seeing at 25psi? There's only rated for 35lb/min that's a small 16g and a evo3 is rated at 47lb/min. Are you running a afpr or stock fpr?