Hey guys, I have an 87 305 IROC and am running a very slightly modified AUJM 6E.bin. I am very new to this so bear with me here.

Ever since switching to 6E, I have disabled VATS, set my mask id to AA, played with my fan on/off temps, set the aldl spark adder to 0, and that is about it.

I am taking things slow and am just trying to get it to run right during idle and at a slight rev to 2000 rpms. From the moment I turn the car on my BLMs shoot up to 146 and does not budge. I have a fuel pressure regulator on the car set to roughly 48-49 psi. I gutted my MAF screens which probably helped lean it out, I have tried boosting my injector flow rate but the BLMs still did not move. I adjusted the numbers in the MAF table 1 at 55 and 73 volts but by increasing it that did not change the BLMs either. There was nothing wrong with the car before I started burning chips for it and all components should be in good condition.

Is there something wrong here? Am I not making big enough changes? Am I making the WRONG changes? Is something else giving me a false BLM reading?

Any feedback on this would be a lot of help.
-Jason

 

Has the engine been modified? If so, what?
Do you have BLM readings before making changes? If so, what were they?

How are you making changes? What software and hardware?

Are you sure the changes are being saved properly? This question is from experience. One way to verify this is to set the desired idle high and read it with a scanner.

A high BLM would be lean, so boosting the injector flow rate (I assume you mean numerically higher) would be the wrong direction. For my speed-density AUJP bin, going one number up or down (ex. 22 to 21) in the injector constant will change BLM numbers by as much a 10 points.

Ed

 

Sorry I forgot to specify what equipment I am using here... I am using Tunerpro RT with Craig Moates ALDL cables.

The engine has not been modified.

With my old 32B bin it still ran lean but not quite as high; at idle at least. I think it was around 136 or 138.

I am sure I am saving my changes properly but I will certainly do the idle rpm test you mentioned just to be REALLY sure.

I guess I did go the wrong way on the injector flow rate however. Oops! I would still have thought it would have at least made it even leaner don't you think? The BLMs just stayed rock solid at 146.

Let me know what you think. Also let me know if I left out any vital information you need.
Thanks for your help.

 

Jason

I wish I could help you more, but I do not have any MAF tuning experience.

If you are sure the changes are taking effect, I would try a lower injector constant just to see if it makes a difference. If it does, you should only consider it a band aid. That is not the preferred method to solve the issue.

Best of luck, Ed

 

Ok dang I just had my numbers backwards there. I was increasing the number size thinking thats what I had to do. I bumped it down to 19 and it ran nearly perfect. So I guess my next step is to put it back up to the stock level (since I just have stock injectors) and then tweak my MAF tables?

Can somebody confirm for me which way I go on the MAF tables... I thought I increased the number size there too to make it richer but since I got the injector rate wrong.... I want to be certain.

Let me know!

Also, could somebody explain something to me? In Tunerpro, when adjusting my single and double fire FI size it says it is reading in lbs/hr... So it seems to me that by making that number bigger, you are increasing the amount of fuel... That was my logic anyway.

 

The code calculates an afr.
Changing the physical injector size will add fuel for the same PW.
So to maintain the same afr. An increase in Inj size in the code will cause a decrease in PW. Assuming that is the only change.
Another way to remember it in math terms is Air/inj size ~ PW.
So a bigger injector setting will decrease the PW for the same amount of air.

There are several MAF table threads in the stickies. The are also a couple of zips on moates.net about maf tuning.
With a stock engine, you don't need to up the FP to get more fuel flow.
So I'd recommend putting that back too. Then adjust your tables to compensate for the screen removal as detailed in the stickies.
Most of your problem is due to the screen removal based on all that I've read on here about it. Basically that mess's with the low flow characteristics of the meter and makes things incorrect for the stock tune.

 

Ok that makes a lot more sense to me now. Thank you for your reply. People like you guys are what makes this website so great.

 

hey camaero if u have any other questions in the future shoot me a pm or something, since im doing the same stuff with my roc

 

Your stock 305 injectors ARE 19 lb/hr, unless you changed them out. AUJM is a 350/auto bin with 22 lb/hr injectors. Set the injector constant to 19 if you still have them in there.

 

Ok, I was trying to remember what the stock injector rate was. That is a big help.
Thanks.
-Jason