View Full Version : Help me figure this dyno sheet out please
Honda Hunter
09-15-2005, 01:51 AM
I recieved a mail order tune from the states. After installing the tune the car ran 110% better except for the stench of fuel all the time in the car. I took it to the dyno last night and it made horrible numbers. Here are my mods:
~1994 Z/28 Camaro A4 convertible~ LT4 corvette motor swap, 190 AFR Heads, Ported LT4 intake, 4.10 gears, 3500 Stall Yank Converter, Edelbrock Exhaust, Hooker Long tubes, MSD Ignition, 160 thermostat, Fully built bottom end, Underdrive Pulleys, MSD Wires, Comp Cams 230/244 .510/.540, Transgo shift kit, Moroso cold air intake, 58mm bbk throttle body, 3 inch exhaust pipes, No cats, fan mod, egr delete, stock LT1 Knock sensor, The general elevation of Bahrain is low with low air density.
I made 275/265 with a a/f of 10. Everyone is telling me it's the tune. I was also told it's my ignition but the car drive fine, no indications whats so ever of ignition issues. I think it's running way to rich and I'm posotive the Knock sensor is pulling timing. Please help me figure this out. I need as many opinions as possible. Thanks
http://www.mustangmods.com/data/552/picture001.jpg
http://www.mustangmods.com/data/552/picture.jpg
LS1-450
09-15-2005, 06:51 AM
Have the guy @ the dyno adjust your fuel to as close to 13:1 as you can get it through the RPM range @ WOT. Also looks like the underdrive pulley may have a balance issue as seen @ 5,400 & 5,600 RPM on the second dyno & possibly is the cause of the reduction @ 4,700 on the first. Adjust the fuel & go from there. If the dip remains after fuel is corrected, would consider a new ASP or equal harmonically balanced pulley. Good-luck
Honda Hunter
09-15-2005, 01:28 PM
Ok this is what I have gathered. The tune is rich but I was told there may be other things at play causing this other than the tune. For sure I need to check the ignition, cam (may be a tooth off) and tune out or replace the km with a lt4 km.
I wanted to do some data logging but nothing Ive tried will read my computer. I dont know if it's the cable or what. Seems like the cable is working but every program Ive tried nothing shows up on the screen. It acts as though it's not plugged in.
My questions are:
1: How do I go about testing my ignition to ensure it's fine and not the problem?
2: How do I determine if the cam is a tooth off or so?
3: How do I use the akm usb cable with data master?
I'm at my wits end with this. If it isnt one thing it's another.
Mir Hussain
09-15-2005, 07:42 PM
Hello my Kahil, first of all your Car running like a SHIT.
1. Take off Underpully
2. Add LT4 Knock Sensor (If the PCM is 95-and uo)
3. Re run it.
Your A/F ratio at WOT should be 12:1 and normal Driving it should be 14:1.
My Mods are as follow and I make 320RWHP and 340RWWTQ
CAI
160 T Stat
Meizer Electric Pump
1.6 Roller ROcker
LT4 Valve Spring
95 Mac Headers with ORY
Borla Exhaust Full open.
Honda Hunter
09-16-2005, 03:01 AM
Hello my Kahil, first of all your Car running like a SHIT.
1. Take off Underpully
2. Add LT4 Knock Sensor (If the PCM is 95-and uo)
3. Re run it.
Your A/F ratio at WOT should be 12:1 and normal Driving it should be 14:1.
My Mods are as follow and I make 320RWHP and 340RWWTQ
CAI
160 T Stat
Meizer Electric Pump
1.6 Roller ROcker
LT4 Valve Spring
95 Mac Headers with ORY
Borla Exhaust Full open.
Kah-fa-halic sah-dic. Hah-biby, today I recorded some data logs using freescan and TTS Datamaster. I sent them to the tuner in the states. I'm hoping he can use the logs to perfect the tune.
As for the pullies I really want to see how everything goes with the new tune first before I go through the headache of having them removed. The tuner told me he sent me a lt4 knock sensor for my 94Z but I guess it got lost in the mail.
During the runs I noticed alot of things going on. I had two codes:
code64- Right o2 sensor lean
code33- Map sensor high
I also saw alot (not exactly sure how much knock is alot)
of knock during the logging. Had some at idle and alot throughout the rpm's. I feel as though I'm getting close to getting this figured out.
Also would a tuner be able to see ignition problems and be able to tell if the cam is off by a tooth or so by looking at data logs? I want to get this all handled before I get back on the dyno. I cant affor to keep paying BD25 for horrible numbers.
Mir Hussain
09-16-2005, 03:10 AM
tunner can only see what ever logs says.
It appears to be you have a bad sensor or wire.
Sound like you found the problem.
Pullys hardly give ya any thing.
I personally have NICE A/C and stereo going at 1800 RPM then NO A/C and getting cooked at 35c
First fix the sensor stuff Then log it.
Once every thing running good, then you do the tunning.
False knocks can retard the timming +20 or may make you run totally in LIMP mode
Mir Hussain
09-16-2005, 03:12 AM
BTW what is the market for Lumina SS for 2003-4 Year Model.
I am thinking about gettting one :)
Honda Hunter
09-16-2005, 03:21 AM
tunner can only see what ever logs says.
It appears to be you have a bad sensor or wire.
Sound like you found the problem.
Pullys hardly give ya any thing.
I personally have NICE A/C and stereo going at 1800 RPM then NO A/C and getting cooked at 35c
First fix the sensor stuff Then log it.
Once every thing running good, then you do the tunning.
False knocks can retard the timming +20 or may make you run totally in LIMP mode
I hope that's it. I should be outside looking at it now but it's hot and it's break time till at least 3pm. I want to go to the dealership to see if they have a map sensor but it's Friday :(. The map sensor is on the intake correct? Also on the logs I noticed it always read "closed loop" WOT or ideal it always said closed loop. I wonder what that means?
Honda Hunter
09-16-2005, 03:22 AM
BTW what is the market for Lumina SS for 2003-4 Year Model.
I am thinking about gettting one :)
I'm not sure. I wanted one for a long time but I found a unbeatable deal on the Camaro I have so I never looked back. Lumina SS are great cars. Mabey one day Ill get one.
Mir Hussain
09-16-2005, 03:35 AM
I hope that's it. I should be outside looking at it now but it's hot and it's break time till at least 3pm. I want to go to the dealership to see if they have a map sensor but it's Friday :(. The map sensor is on the intake correct? Also on the logs I noticed it always read "closed loop" WOT or ideal it always said closed loop. I wonder what that means?
dont buy; let them try out and log it.
I have seen getting real weird reading by having Opti Spark leak or some time cable getting pinched.
MAF sensor is between Throttle body and CAI.
When engine is cold or running in Limp Mode it will show OPEN Loop (Not Good)
when computer getting all data from the sensors and every thing with in the Range it goto Close Loop (Good THing)
When you hit WOT, OBD should go in P.E mode Power Enrichment which is 10% more of LT. Should able to do is 12:1 ratio.
Mir Hussain
09-16-2005, 03:37 AM
BTW do you all have 02 Sensor and MAF ?
I would be thinking there would be No Emission provisioning.
Car may run in open mode.
We have those stuff because of EPA :(
Honda Hunter
09-16-2005, 03:55 AM
dont buy; let them try out and log it.
I have seen getting real weird reading by having Opti Spark leak or some time cable getting pinched.
MAF sensor is between Throttle body and CAI.
When engine is cold or running in Limp Mode it will show OPEN Loop (Not Good)
when computer getting all data from the sensors and every thing with in the Range it goto Close Loop (Good THing)
When you hit WOT, OBD should go in P.E mode Power Enrichment which is 10% more of LT. Should able to do is 12:1 ratio.
I just went over the log again and I see knock Retard Alert indicator was reading "Spark Retard = 5.0" in most of my WOT runs.
Honda Hunter
09-16-2005, 03:56 AM
BTW do you all have 02 Sensor and MAF ?
I would be thinking there would be No Emission provisioning.
Car may run in open mode.
We have those stuff because of EPA :(
We have inspections. There not as strict as other places though.
Mir Hussain
09-16-2005, 11:18 AM
I just went over the log again and I see knock Retard Alert indicator was reading "Spark Retard = 5.0" in most of my WOT runs.
Too much
find out where is the knock comming from?
Honda Hunter
09-17-2005, 07:37 AM
Too much
find out where is the knock comming from?
I'm almost posotive it's false knock. I'm thinking that's what's messing up my a/f ratio. I have the stock LT1 km it I hear it's really sensative.
Mir Hussain
09-18-2005, 01:21 AM
I'm almost posotive it's false knock. I'm thinking that's what's messing up my a/f ratio. I have the stock LT1 km it I hear it's really sensative.
False knock will rich your Mixture up
You running Way to much lean
Computer doesn't know if its a False knock or real knock.
it will retard the timming the regardless off
Honda Hunter
09-18-2005, 03:07 AM
False knock will rich your Mixture up
You running Way to much lean
Computer doesn't know if its a False knock or real knock.
it will retard the timming the regardless off
Do you think that's what the problem or do you think I may have other issues?
Mir Hussain
09-18-2005, 08:58 AM
Do you think that's what the problem or do you think I may have other issues?
You have multiple issues
1. Bad sensor or read out
2. Knock
I think your Tunning is ok
First fix all mechnical issues and then look for sensor errors
Honda Hunter
09-18-2005, 11:20 AM
You have multiple issues
1. Bad sensor or read out
2. Knock
I think your Tunning is ok
First fix all mechnical issues and then look for sensor errors
Thanks for the advise. I'm going to have both o2 sensors replaced. I'm not sure how I'm going to handle the map sensor though. If it's not expensive I'll just replace it. I may also put some race fuel in it to see how it does.
Mir Hussain
09-18-2005, 12:21 PM
can you borrow for a little while ?
Honda Hunter
09-18-2005, 01:59 PM
can you borrow for a little while ?
Pretty sure I can.
Mir Hussain
09-18-2005, 06:11 PM
Pretty sure I can.your best is have GM Tech figure out or somebody who have TechII. Its lot easier for you, if you do this way
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