stevo92z28

iTrader: (22)

New motor, just got it back from tuner and buttoned up a few things that it needed.

It's a 233/239 on 112 cam with 243 heads. It put down 433 at the wheel and runs great at WOT.

I have an idle issue that comes and goes. Normally have it most of the time. It hangs and car will actually drive itself. When coming to a stop it will creep up then wont fall back down for another 2-5 seconds. Give it gas it goes up hangs and same thing 2-5 seconds to come back down. Working the clutch/brake pedal won't change a thing.

Im searching trying to figure out how to view IAC counts in VCM Scanner. The editor is showing 310? TPS shows 0% when it hangs so it's not a throttle cable/blade issue.

I have cleaned MAF/IAC
Switched to new paper filter
Fixed the exhaust leaks

I have sprayed everywhere while having the issue and cant find any vac leak. I would assume it would have to be a pretty large vacuum leak to cause idle to hang at 2k rpm.

Does this sound like a tune issue? I'm not concerned with my tuner and he will take care of me but just want to make sure it's not an issue with my car or install before i take it back. Hes an hour away.

Thanks for any input.

SWEET98SS

iTrader: (8)

Did you check the small line that goes from the back of the intake to the heater box? Ive had this come off.

stevo92z28

iTrader: (22)

I did and it's on.

badazz81z28

iTrader: (6)

I have the same issue...Random and nobody seems to have any insight as to why. Some will tell you too much air, which yeah...but the random part is what makes it difficult to solve.

Black 99 Bird

iTrader: (31)

It is in the tune. When I had my cam put in, which is just a little bigger than yours, it did the same thing. I took it back to my tuner and he fixed it no problem. He said something about the throttle cracker & rolling idle. Do a search for hanging idle or throttle cracker and you should get lots of hits. Narrow your search to the PCM Diagnostics & Tuning section to help weed out false hits.

badazz81z28

iTrader: (6)

Please let me know how this works out for you. I zero'd my throttle cracker table and no change. With the issue being random, I don't see how the cracker or decay is it. I'm desperate for a fix too!

BrntWS6

iTrader: (7)

Definitely in the tune...this is what happens when you pay someone $400-$600 and they are too f'ing lazy to tune for driveability on the street. The right way to tune the car is for them to have it for a couple days....tuning for WOT is easy.

flattusmaximus78

iTrader: (1)

You should check the pcm section. There is a few tuners that could easily help you fix that.

To the op, my car has a similar cam to your car. It is an a4 car though. Mine did it with the a/c on. When I let off the brake it would pull the car forward and I'd have to stomp the brakes. Or it would be coming to a stop at like... 1100 and it was annoying. Too much air is what I was told.

I think it's great that your checking under the hood, but call your tuner up. It took literally 2 seconds to fix.

Alvin@PCMofNC

If the IAC counts are at 310 its asking to open the idle for some reason. Are you sure the TPS is always reading 0% while coming to a stop? It sounds like a tuning issue. If it was a vacuum leak the IAC counts should bottom out (0)

stevo92z28

iTrader: (22)

Thanks for feedback. It's going back to tuner tomorrow and hes going to spend some time with it. Hope he can get it figured out. I will post back what we find.

I can't figure out how to view IAC counts in the scanner so i really don't know what they are.

poltergeist 02

iTrader: (65)

is your tps voltage around .57v at idle?

HioSSilver

iTrader: (8)

What tb do you have?

gagliano7

In your scanner table insert IAC position . Find a blank spot on table right click, click insert under pid list click engine than idle than double click on IAC postion and it will be in your table.When i was trying to figure it out everyone says scan IAC counts and i couldn't find it. Then i figured out it was IAC position. Why know one can tell you that is beyond me. You can also scan IAC desired position but on mine they both show the same #.

badazz81z28

iTrader: (6)

Can you post your tune?

stevo92z28

iTrader: (22)

TB is a ported SLP. Tuner got it figured out pretty sure it just needed the IAC adusted.

Also figured out IAC position in HPTuners.

Thanks all.

badazz81z28

iTrader: (6)

IAC adjusted? How the hell do you do that?

All you can mess with is airflow.

stevo92z28

iTrader: (22)

Airflow screw or whatever is what I meant. I feel like tune still needs some work, still getting P0300...they said the coils might not be grounding correctly because i didnt have all the bolts installed. I put a lot of miles in traffic today which wasn't fun. I'm not really sure what kind of results to expect with this cam which isn't that big. I'm still getting lots of surge on cold start and the P0300...I will get a stumble if i don't give it enough gas off the line. Falls on it's face for a brief sec.

They scanned with tech 2 it was showing multiple knocks on every cylinder at idle. Give it gas and they all zeroed out. This is common because of the lope of the cam right? What perimeters can i change so its not so sensitive but it will still detect a real misfire?

gagliano7

I have read before with some cams you will get ramdom misfires..There is something you need to do but i can't remember.

Misfires. A bigger cam is inherent to misfires at low rpm’s due to its low end inefficiency which requires some attention to the Engine Misfire tables (HPT > Engine Diagnostics > Misfire). I do not have a general guideline here other than increase all tables. The max value you can enter is 32767 so I would suggest starting with 20% of that number and increase as you trip a DTC for the P0300 (Random Cylinder Misfire code). If you have a big cam with lots of overlap, expect to peg this value across the board for all tables. If fact, I ended up deleting the P0300 code as it was a nuisance. Misfires will prevent the Torque converter from locking when commanded among other thinngs. Deleting this code prevents this in my case.

http://www.hptuners.com/forum/showth...highlight=idle

Here you go.

turyg ls1

iTrader: (2)

[QUOTE=BrntWS6;17395358]Definitely in the tune...this is what happens when you pay someone $400-$600 and they are too f'ing lazy to tune for driveability on the street. The right way to tune the car is for them to have it for a couple days....tuning for WOT is easy.[/QUOT
Yup! When I took my car to get tuned for a heads & cam he wanted it there for a couple of days cause it takes time and also driving it on the street