SD??? I know, I know...
SD??? I know, I know... Ok, I know the search is busted & ive read through 15+ pages so I figured I would just ask. Im in the process of doing a SD tune on my 408, because the MAF is going to be the bottle neck in my setup. Well I read all this info on what to do, I do it then I see other threads talking about turning other options off, changing the secondary ve table & etc. Ive read the instructions that was posted on HPTuners forum, & the car just doesnt act right while tunning it. The car surges, smokes & dies. I have a feeling theres more to it than just what I read. My question is, is there a link on how to a SD tune the correct way? Or maybe a link you guys have used that worked perfectly. Here is the link that I have originaly been going by.
http://www.hptuners.com/forum/showt...t=speed+density
When I unplug the MAF, & disable the SES lights, is the car suppose to smoke, spit sputter & barely idle? Is this normal until its tuned out or is there something Im suppose to chenge for that also?
http://www.hptuners.com/forum/showt...t=speed+density
When I unplug the MAF, & disable the SES lights, is the car suppose to smoke, spit sputter & barely idle? Is this normal until its tuned out or is there something Im suppose to chenge for that also?
I did not have any problems doing an SD tune. I currently do not have a MAF and run open loop all the time. I used the EFILive SD tune process but I have Flashscan and not HP.
Good Luck.
Bill
Good Luck.
Bill
Originally Posted by RedHardSupra
how's your IFR setup? is displacement accounted for?
Flow Manifold Vacuum (kPa)
51.09247 0
51.40250 5
51.77453 10
52.08456 15
52.39459 20
52.70461 25
53.01464 30
53.32467 35
53.63469 40
53.94472 45
54.19274 50
54.50277 55
54.81280 60
55.18483 65
55.37085 70
55.74288 75
55.99090 80
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TECH Fanatic
Joined: Aug 2005
Posts: 1,691
Likes: 1
From: Sunny London, UK
Here are some ideas which might help.
Though Im no expert,
Your ve is very important on cold startup (open loop) in SD mode.
Can you get any logs at all?
Will it hold rpm at part throttle?
If you can get it to run at 1500 rpm with the throttle and get some logs to post we might be able to help.
You could log airflow with the maf and if you can get it to run with SD compare the flow. That might show you if you need more or less air dialed into the VE table.
Also you could get it hot with the maf, then unplug/disable it and fire it up again, it should go into closed loop pretty quick which will help with fueling.
If it runs SD when hot your logs will definately show you lots of nice info.
Though Im no expert,
Your ve is very important on cold startup (open loop) in SD mode.
Can you get any logs at all?
Will it hold rpm at part throttle?
If you can get it to run at 1500 rpm with the throttle and get some logs to post we might be able to help.
You could log airflow with the maf and if you can get it to run with SD compare the flow. That might show you if you need more or less air dialed into the VE table.
Also you could get it hot with the maf, then unplug/disable it and fire it up again, it should go into closed loop pretty quick which will help with fueling.
If it runs SD when hot your logs will definately show you lots of nice info.
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Verdad Gallardo Id have to check the fuel pressure to let you know. The car will idle without the MAF, but smells like straight gas & will surge up & down till it almost dies. My LTFT's at idle are anywhere from 13 to 17 so its defiantly lean. I was thinking get the car warmed up, the do some logs while its idling to get the VE close at idle then go from there. Would this work? The reason I started this thread was to get a link or info on how to properly do a SD tune. The link I posted above, is it correct or is it missing some things. I know in the help section of the VCM editor it gives you directions for SD tune but has many different steps then the link I posted. Does anybody have a link or instrutions on what to correctly do?
TECH Fanatic
Joined: Aug 2005
Posts: 1,691
Likes: 1
From: Sunny London, UK
I think you may have some idle problems then.
Let us know if it runs nicer when off idle. You might find if you sort idle out the rest is ok.
Sounds like your overlap is dumping unburnt fuel and O2 into the exhuast, which the PCM is seeing as lean so its adding fuel as per your trims (Did you reset the trims?) Viscous cycle.
Take a look at some idle tuning threads and see if they help with some idle tuning tips.
Let us know if it runs nicer when off idle. You might find if you sort idle out the rest is ok.
Sounds like your overlap is dumping unburnt fuel and O2 into the exhuast, which the PCM is seeing as lean so its adding fuel as per your trims (Did you reset the trims?) Viscous cycle.
Take a look at some idle tuning threads and see if they help with some idle tuning tips.
I had to adjust my running airflow tables before my car would even run at all with the MAF unplugged. Use the RAF histograms to get the RAF in line first and I bet it will cooperate a lot more...
Good luck,
Rob (Bad30th)
Good luck,
Rob (Bad30th)
