LE5

So I've noticed with my intake I run at 29.7% LTFT while driving around, it'll drop down a bit but generally stays pretty high. I swapped my stock intake back in and was running at 7% LTFT. So I swapped my stock PCM back in and was running at 7% still.

Since then I've replaced my tuned PCM, and my intake. Still running at a higher LTFT, but it drives pretty normal for the most part and my mileage isn't too bad.

I'm just seeing if any of you have run into this when installing an intake.
It's the 2.4 LE5, I have a 93 octane tune that should be written for the intake.
I've checked and found absolutely no air leaks anywhere around the MAF or any joints.

Any suggestions for anything else I should look at?

Oh also, what range of voltage should the o2 sensors read? I never see them go above 0.9v

insylem

If you have tuned it and are still running high fuel trim, maybe your intake is leaking some where.

prevsrt4owner

That's a $hitload of fuel being added, lol. Definite issue if you're in the double digits -/+. Sounds like a vacuum leak to me. Possibly leaking fuel injectors. Also, 7% isn't bad.

A smoke test would be your best option.
Just use a cigar, lol.

No mention of codes. P0171?!

user 72239

iTrader: (4)

p0171 is usually system bank lean. you could be having cylinder wash with that much fuel. sounds like something is leaking

LE5

I popped a code over the summer, but It was right after I yanked my exhaust apart going down an off-road path, I was driving down the highway about 3 hours into a 5 hour trip and the light popped, I scanned it with my phone and got:
P0101: Mass or Volume Air Flow Circuit Range/Performance Problem

I cleared it and kept driving, never came back. I drove for a few months, until I noticed that every so often the motor will hesitate when I try to accelerate from a stop, it was really random, If it happened once, it'll keep happening until the next time I started the car. But who knows when it would happen again.

I eventually learned that every time the motor starts to hesitate, I have a pending code P0101. no light, but just a code.

As I kept monitoring crap I eventually found out what happens, Get ready for some more reading!

If I'm driving more aggressively, or just highway driving over 80 mph, my 29.7% LTFT will drop WAY down to like -6% it'll bounce all over the place in between before finally settling around 10.7% while I drive around, It would drop when coasting. During this moment of heavy change, the car will show a Pending code for P0101.

I determined it must be the MAF adapter in my intake, that POS ebay thing never looked right and the MAF never felt like it sat right.
So I got a Spectre MAF adapter with the inserts and all. Popped it in, and have done everything in my power to try and get the code to come back or the fuel trims to change. No dice.

So at this point I'm fairly confident that little issue was resolved, no more hesitations or anything.

I also replaced the MAF with a new AC Delco one about a month ago, just for good measure. Nothing changed



So How can I go about smoke testing my intake and evap lines? Should I just hold said cigar around the pipes while idling and look for flow? Or is there more to it?

And just to be clear. I check for fault codes after each trip to work and each trip home. Not a single code has popped up in probably 2-3 weeks.

prevsrt4owner

Here's a good video that gives you an idea of how to perform the smoke test.

LE5

Well I actually just dropped in one of the inserts for the MAF sensor to decrease the diameter to 2.5" When I put that in the LTFT dropped and runs close to what it did when stock. But it ranges from -7% to 7%, but I think it's still adjusting stuff.

prevsrt4owner

-7% - 7% sounds A LOT better, man. I'd just stick with whatever you're doing.

LE5

The thing is, when I have the insert and it runs like that, it just doesn't feel right at all. Acceleration is inconsistent and I just loose all confidence in my engine. So I only want to run it with plain intake.

My buddy was telling me that's MAF scaling and I'm not really getting anywhere doing that. I need to do some proper logging and get down to it.