Al, I got a custom flash from you at pruven back in August Case# 86. I love the flash, but lately have had a slight misfire at idle. It has loged the code only once. I cleared it and then when I put it on the dynojet near me to see what the A/F ratios looked like, I was surprised to see 10:1 A/F's from 2800rpm to redline but there was no power loss from when you flashed the car last. Do you think it is an ignition problem, ie. bad wire,bad plug? I believe this is far to rich to be your tune for just Intake, downpipe,cat-delete pipe and cat back exhaust. Is this a mechanical problem causing this? I need your help to hunt down the problem and fix it.

 

On your flash all idle tuning settings are 100% stock - if it idled well after the tune and now is is having what you describe as a "slight misifre at idel" you should look to some mechanical change since the tune as the tuning paramters for idle remain unchanged

Some possible examples may be

1 - vac leak / leaking bov

2 - Spark issue / groudning issue

As for your dyno you should send me your sheet and the details of your tune methods - e.g. gas used, boost used, gear pulled, number of pulls, time between pulls etc.

To your questions - I like to see a 11.1 /1 - 11.3 /1 a/f as when i set your car

10's / 1 a/f is too rich - however - improper dyno procedures can make the mixture go richer by up to a full point if the collant temps are hotter than normal operating temps

One of the reasons why I am so careful in the manner in which i do my dyno pulls to remain consistant and accurate

As for your 0300 issue - sine you only got it one time - its bot really an issue

i attempted to return your call on Friday even though I was in NC but got your shop answering machine

I think the best soultion for you is to bring the car by so I can listen to it and you can put the car on the dyno and I can make what ever corrections are needed

On a seperate note - the flash settings are 100% set in stone and do not deviate over time. When a/f numbers change its either due to variations in test cololant temps or due to mechanical changes.

 

Thanks for the quick response. I will call you tomorrow to set up a time to have you look at the car. I thought that this may be a seperate issue from the flash, but wanted to consult you to make sure.

 

coincidentally - a boost leak (very common) would trigger both a rough idle and a rich condition (metered air escape) first thing to check if you have a pressure tester

 

Just to follow up on this thread - there was NOTHING wrong with this gentleman's tune what so ever

Here is the dyno sheet from the other shop which showed a RICH a/f - in fact the a/f is not even recorded on the dyno graph

Here is the sheet the customer showed me

NOTE - the tune looks perfect and power and tq levels are normal for low boost and no cams

 

The customer came back to our dyno and without changing anything we drove the car onto the dyno with the same 20 psi and this is what the dyno sheet showed

You can see the tune and a/f is perfect

 

Finally - we turn UP the boost to 22.5 psi peak falling to 20.5 and this is what we get - a perfect tune with POWER TO SPARE - nothing worng with the car a false alarm

 

Let me just say that I did not think there was anything wrong with the flash from the beginning and if I led others to believe that I am sorry. I just wanted the man who knows these cars best to help me find the problem, if there was one, and fix it. I was confused by the fact that I had no power loss and the A/F readings from the other shop's dyno made it look like the A/F's dip down below the 10.0 mark on the sheet. Obviously that shop did something wrong when dynoing my car or maybe the sensor they are using is faulty. I have not had the 0300 code since then and have had no problems at Idle. This was an isolated issue that may have been nothing more than bad gas. Thank you Al for taking the time to look at my car and for putting my mind at ease. You are a true professional and a kick *** tuner.

 

very impressive...