I tried searching and found a topic about this and effecting the LSJ's. They fixed it by cleaning the intake sensors and throttle body just wanted to see if this could be my issue as well?

At cold start my balt is idleing rough. I turn the key the car will normally begin running around 1500 rpm (like it always has as soon as it turns over) but then the RPM will drop suddenly to 800-1000 and it sounds like it's almost about to stall. The BPV will blow out air and then the rpm jumps up again, back to around 1300-1500. This goes on for a bit. Each time it happens though it revs up a little lower each time. Finally after 30-60sec it runs ok at regular idle RPM, but it still flutters a little maybe between 600-800 RPM every few seconds?

This only happens at a cold start. Once my car is warm it starts just fine and idles fine. No issues when I am driving it at all. Does this sound like I need to clean the intake sensors/throttle body? Or do you guys think it may be something else? It's been going on for a few months now but has gotten worse within the last 3-5 weeks.

Any ideas would be great, this makes me want to bang my head against the wall when I start it in the morning.

Edit: I recently have been tuning my car and was wondering if that could have anything to do with this?

 

Bump

 

could be maf or map sensors going bad are you tuned? if so do you have cat warm up delete?

 

Yea i am tuned. I do not have a cat warm up delete. Never heard of one to be honest. Is there any way to see if my map/maf are going?

 

not that i know of, a friends car had that happen though when his sensors were going, are you hp tuned and did they mess with cam tables?

 

was there a drastic weather change aka hot to cold happens to me when winter nears

mostly every car does it

 

Nope, no dramatic weather changes, unless you consider the spring-summer in upstate NY at dramatic weather change haha.

It's HP tuned my cousin and I have been working on it the last few weeks. Im almost 100% sure we didn't touch the cam tables.

It's only doing this on the cold start after it sits over night. The entire rest of the day it is fine. I have no idea what's goin on.

Go figure this would happen AFTER I tune my car (I mean why would this happen before?) so now the dealer is going to give me **** about that if it is the maf/map sensors.

 

One of the easiest ways to test the maf and map sensors is by simple logging the maf sensor frequency and both map sensors for voltage at any given rpm and load to make sure there are no skewed/off sensor responses for you commanded air loads and boost. Seeing as how you said you tuned the vehicle this should be easy enough for you to do.

 

Awesome. Thank you!! I'll try that this weekend when I go to his house.


Anyone have other ideas that may be my issue here? Incase my sensors are fine

 

Mine do the same since 3 months. I cleaned the maf it helped the fuel economy but other than that it still almost stall on cold start. And will run up and down for a couple seconds then run fine when hot.

Can it be the O2 sensor ? (not the one on downpipe...)

 

This is so weird, my car is doing the EXACT and I mean EXACT same thing with the exact same symptoms and everything. I'm somewhat happy that it's not just me and maybe we can work at this together.

Everything else about the car is perfect. I have a new MAP sensor, evap purge solenoid, front O2 sensor, new spark plugs, cleraned the MAF, fresh oil, did a compression test and are all 155+ across all cylinders and I have been trying to retune my fuel trims.

I think it might have something to do with me tuning my fuel trims because it started after I "thought" I was done. They have been really hard to pull into line and I've been letting them settle the past few days. My LTFT's are at +1 right now and my STFT's vary all over the palce from -9 to +9. When I go WOT at around 3000 rpm, mt STFT's spike to -14 and then settle to 0 as I climb to redline. It also gives me phantom/false KR.

I am also going to try and take a look at my throttle body to see if residual gunk from seafoaming compromised it... But I think it might be fine as my problem only comes from a cold start and it won't idle right until I give it some throttle or once it starts to warm up.

 

Sounds like we actually do have the exact same issue haha. Is it tripping your SES light? I haven't touched my fuel trims while tuning so maybe that rules that out? But I'm not sure. As I am a just learning about tuning so I'm rather n00bish.

 

Nope, no SES light. But I did have a pending code P0476 (Evap Purge Solenoid stuck closed) after a few days. That might be part of the problem. I have another one on the way to switch out and see if it helps. I thought the code might have been a result from doing ym fuel trims as you unplug the solenoid, but I had cleared it and it came back... so I am not sure anymore.

And be careful with the tuning. Don't make big adjustments to things until you are comfortable and know what you're doing. I still question my fuel trim tuning methods but it seems I'm on the right track and doing everything correctly. There are just other underlying problems that I need to take care of before I can continue tuning. Fix the car, then tune

 

Sounds like tune to me.

Can't you put it back to stock for a bit and see if it changes?

 

I think so as well... But the only things I changed from before this happened to after were my fuel trims. The OP didn't change the fuel trims. BUT, what we both have in common is the removal of cat warm-up....

Now, I heard that with the new HPT BETA that's out, some have had weird idle problems upon cold start when removing the cat warm-up.... This is even after adjusting the cam tables to better suit the cat warm-up delete. I feel it might be a weird software bug, but I can't be 100% sure.

I need an inspection before months end so I have to get all my OBD II readiness monitors all set before i tinker anymore. Everytime I flash the computer it resets those monitors to "Not Ready" and it will fail emissions like that... it takes about 6 drive cycles to get them back which is about a week or 150 miles fore me.

I'll keep looking into this, though.

 

Thing i noticed, ive been tuned for at least 18000km using the tune everyday not a single problem, installed my K&N intake and it all started not a long time after the install.. for the fluctuating idle, the almost stalling issue was worst a little after i installed the downpipe.... then i got retuned, fuel trims were slightly off car run smoother but the cold start problem is still there.

So we can say its not the MAF, front O2, i also changed the purge valve and it did nothing for that.

 

Mine does this too... Once I get going though it seems to be fine.
And I'm not tuned.

 

I'm going to try a few things after I get inspected (Once my OBD readiness monitors are all set). It could be a little while though

 

What's this cat warm up you speak of? I have a ZZP DP with a highflow cat. And we never touched anything in the tune with the cat? Like I said I have no idea what it is haha

We used the newest HPT beta as well. But it really wasn't any worse afterwards. We've been very careful tuning. My cousin is doing it while showing me the ropes. I'm pretty sure we've only adjusted 2 tables (which 2 I forgot are called, I'll double check).

I also have an intake. But it's been on for almost 2 years. So that doesn't add up.

 

ooohh, I thought you had turned off the cat warm-up. Basically, it's the high idle at cold start-up. If you turn it off, you have to play with the cam tables to get it to idle correctly.

Once I get the new evap purge solenoid I'm going to see if the problem goes away. It still has a pending P0497 code. I think that's my issue. If not, I'll be re-tuning my fuel trims anyway and hopefully that's the cure.

And there are a lot of tables that need attention. You really can't just adjust 2 tables.... I mean, you could, but it's not advised lol.

 

mine did this, messed with cam tables and smoothed them out and now its fine. Could be your trims.

Gremlin have you ever changed your purge solenoid? might be time for a new one i know alot of people around me have had to get new ones.

 

My car did it when the weather was changing (temp) was changing drastically a lot, it's stopped since the weather has been consistent.

 

I was changing nothing in my tune except my fuel trims. At the same time I've gone through 2 purge solenoids. I have another one on the way. I think it's gotta be that.


My car has never done anything like this in the 2 years I've owned it. I'm banking on a purge solenoid being faulty.

 

Well I had the GMS1, we copied that tune. And have been adjusting that as we go along. But the tuning has haulted since I've noticed this. Are you getting the solenoid covered under warranty? Let me know how it works. My uncle is the warranty guy at the dealership I got my car at and he warned me not to touch it. Well that's like telling a little kid not to stare at the sun when its a solar eclipse, of course I touched my car haha. So obviously I don't want to void my warranty.

Also, another time any tuning help would be much appreciated once this issue is fixed!

 

maybe, but i was saying i smoothed my cam tables and it got rid of even the rough idle with cat warm up delete, but probably your purge solenoid again idk.