24x hell
#1
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Well injectors didn't fix this car either. All signs pointed to having at least three leaky injectors but that isn't this cars problem I guess.
So lets go way back, to last November, the beginning. This car has never ran right on the 24x system. I thought maybe the tune, or maybe something else?
Well below is pictures taken from my tune file.
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/sparktable1.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/fuelflow1.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/bankselect.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/dwell.jpg)
Here is a video I took this morning. Skip to about 1:50 is when I try to accelerate smoothly down the road to 55mph, you can see how the RPMS hang and the car does not accelerate the way it should. Also the first start of the morning the car starts normal, but the rest of the day I need to crank for an extended period of time while playing with the throttle to get the car to start.
My car that runs like garbage.
Here is a datalog. I used megaupload to upload the file. I used EFI Live to make the datalog.
If bank 1 is the driverside and bank 2 is the passenger side, then the fuel trims make ZERO sense. Its always pulling fuel from the side that is normally lean anyway and adding fuel to the side that is already normally rich?
I am at a complete loss. Perhaps my LT1 brethren can be of some help, I've had zero responses in the PCM section.![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
I replaced 36 lb/hr. seimens-deka injectors with 30 lb/hr Ford redtops. I found an excel spreadsheet somewhere online, that is where I got my fuel injector flow rate numbers from. Initially the chart only had one value for the whole chart?
It is a cc503, ported heads(local, numbers unknown), stock displacement.
Running truck coils, I found the dwell chart here on tech, that is the numbers I put into the dwell chart. Although I've read they really don't seem to matter one way or the other.
Edit: Also, have strong fuel smell and smoke out of the exhaust indicative of unburnt fuel. Car will backfire during deceleration while warmed up.
So lets go way back, to last November, the beginning. This car has never ran right on the 24x system. I thought maybe the tune, or maybe something else?
Well below is pictures taken from my tune file.
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/sparktable1.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/fuelflow1.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/bankselect.jpg)
![](http://i16.photobucket.com/albums/b41/camar0corey/94%20Z28/dwell.jpg)
Here is a video I took this morning. Skip to about 1:50 is when I try to accelerate smoothly down the road to 55mph, you can see how the RPMS hang and the car does not accelerate the way it should. Also the first start of the morning the car starts normal, but the rest of the day I need to crank for an extended period of time while playing with the throttle to get the car to start.
My car that runs like garbage.
Here is a datalog. I used megaupload to upload the file. I used EFI Live to make the datalog.
If bank 1 is the driverside and bank 2 is the passenger side, then the fuel trims make ZERO sense. Its always pulling fuel from the side that is normally lean anyway and adding fuel to the side that is already normally rich?
I am at a complete loss. Perhaps my LT1 brethren can be of some help, I've had zero responses in the PCM section.
![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
I replaced 36 lb/hr. seimens-deka injectors with 30 lb/hr Ford redtops. I found an excel spreadsheet somewhere online, that is where I got my fuel injector flow rate numbers from. Initially the chart only had one value for the whole chart?
It is a cc503, ported heads(local, numbers unknown), stock displacement.
Running truck coils, I found the dwell chart here on tech, that is the numbers I put into the dwell chart. Although I've read they really don't seem to matter one way or the other.
Edit: Also, have strong fuel smell and smoke out of the exhaust indicative of unburnt fuel. Car will backfire during deceleration while warmed up.
Last edited by camar0corey; 09-14-2011 at 12:29 PM.
#2
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iTrader: (11)
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Man that sucks with all the troubleshooting you've done so far. you may want to try the efilive or hptuners forums as well. I've seen some discussion there about the 24x setup.
not sure about using that excel spreadsheet for the fuel flow either without seeing the wideband o2 to tell you what is going on.
are you speed density or MAF?
have you had it on a dyno to see the wideband o2 readings?
change your fuel filter?
not sure about using that excel spreadsheet for the fuel flow either without seeing the wideband o2 to tell you what is going on.
are you speed density or MAF?
have you had it on a dyno to see the wideband o2 readings?
change your fuel filter?
#6
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I had went with a new harness from EFI Connections when I did the 24x.
Using a MAF, I also installed a new fuel filter last week when I installed the redtops.
I tried swapping coils side to side, didn't change the fuel trims with that so I think I ruled out the coils.
I also swapped o2 sensors side to side, no change. Two month old o2 sensors also.
I did lower the fuel chart values at one point, while it smelled less like gas and less smoke, it still has the acceleration issues/backfiring and lopsided looking trims in the scans.
Using a MAF, I also installed a new fuel filter last week when I installed the redtops.
I tried swapping coils side to side, didn't change the fuel trims with that so I think I ruled out the coils.
I also swapped o2 sensors side to side, no change. Two month old o2 sensors also.
I did lower the fuel chart values at one point, while it smelled less like gas and less smoke, it still has the acceleration issues/backfiring and lopsided looking trims in the scans.
#7
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I had went with a new harness from EFI Connections when I did the 24x.
Using a MAF, I also installed a new fuel filter last week when I installed the redtops.
I tried swapping coils side to side, didn't change the fuel trims with that so I think I ruled out the coils.
I also swapped o2 sensors side to side, no change. Two month old o2 sensors also.
I did lower the fuel chart values at one point, while it smelled less like gas and less smoke, it still has the acceleration issues/backfiring and lopsided looking trims in the scans.
Using a MAF, I also installed a new fuel filter last week when I installed the redtops.
I tried swapping coils side to side, didn't change the fuel trims with that so I think I ruled out the coils.
I also swapped o2 sensors side to side, no change. Two month old o2 sensors also.
I did lower the fuel chart values at one point, while it smelled less like gas and less smoke, it still has the acceleration issues/backfiring and lopsided looking trims in the scans.
Edit: my comp at work wont support that file. Do you have a wideband on it. If so what are the readings. I would bet anything it in the tune.
Last edited by draggin97s10; 09-14-2011 at 01:30 PM.
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#8
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The "24x system" takes you as far as providing a 24x LS waveform from the crank and 1x LS waveform from the cam. That either works or it doesn't. When it doesn't work, one or more of several symptoms quickly give it away...
Your tachometer looks too smooth to suggest that the 24x system is not working properly.
Your video shows no indication that the harness is faulty.
It really looks like a tuning issue from the video.
- P0336 DTC indicates that the crank sensor has lost (or does not have) a signal from the reluctor
- no spark on all cylinders and not all injectors are firing
- no RPMs in the scan tool
Your tachometer looks too smooth to suggest that the 24x system is not working properly.
Your video shows no indication that the harness is faulty.
It really looks like a tuning issue from the video.
#9
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For what reason did you not follow the recommended fuel flow settings that were described in the tuning guide received with your 24x purchase?
Originally Posted by 24x PCM Tuning Tips
Make any necessary fuel injector flow rate changes. Pay attention to the injector flow rate of the LS1 injectors. The 98-newer LS engines do not use a vacuum operated fuel pressure regulator, so the injector flow rate is a sloping value. If your engine is equipped with a vacuum controlled fuel pressure regulator (TPI and LT1 engines), then the injector flow rate should be set as a constant.
#10
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Thanks Mike, I'm looking into the tune more now. Yeah it has never popped any codes for the crank/cam sensor, and believe me I checked to make sure the reluctor wheel was tight in accordance with the installation instructions also.
I figure the system itself is working, I've been driving on it almost a year.![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
What do you make of the weird fuel trims though?
It just has never ran right. I just put values into my voltage correction chart, as it had the value of just 1.0 throughout the whole chart. Also changed my injector flow rate to 40 psi values instead of 43.
I've had this thing to EFI Alchemy 3 or 4 times. Last time we got it to at least idle, we had to manually zero out the TPS sensor.
Anyone know that for redtops? I heard Ford rated them 30 lb/hr at 39psi some people claim, others say no they were rated 30lb/hr at 43.5 psi.
Mike-I don't think I got a tuning guide? Should I take the vacuum line off then and leave the values as a constant?
How about the correction voltage, also as a constant then?
I figure the system itself is working, I've been driving on it almost a year.
![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
What do you make of the weird fuel trims though?
It just has never ran right. I just put values into my voltage correction chart, as it had the value of just 1.0 throughout the whole chart. Also changed my injector flow rate to 40 psi values instead of 43.
I've had this thing to EFI Alchemy 3 or 4 times. Last time we got it to at least idle, we had to manually zero out the TPS sensor.
Anyone know that for redtops? I heard Ford rated them 30 lb/hr at 39psi some people claim, others say no they were rated 30lb/hr at 43.5 psi.
Mike-I don't think I got a tuning guide? Should I take the vacuum line off then and leave the values as a constant?
How about the correction voltage, also as a constant then?
#11
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New log with fuel injector flow rate set to a constant. I set it to 3.78 across the board. Still wondering about injector voltage correction though? Should leave the chart at 1.0 all across or different?
Car still didn't accelerate as well as it should, still had backfiring when backing off the accelerator.
Car still didn't accelerate as well as it should, still had backfiring when backing off the accelerator.
#12
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Fuel table values are too far from where they belong? Physical fuel delivery issue? Spark issue?
I've never changed values in this table. Is it required?? It would be best to talk with someone who tunes every day.
I've seen this problem with aftermarket throttle bodies.
You did. It's a one-page document included with every 24x package.
I don't think you understand this yet. All TPI and LT1 engines have a vacuum controlled fuel pressure regulator AND all TPI and LT1 ECMs/PCMs have a constant for the fuel flow rate value (no sloping values). When GM removed the vacuum from the LS1 regulator they changed the fuel flow rate to sloping values (as you demonstrated in your screen shot). What I suggest is that you determine the correct fuel injector flow rate (at the PSI you are running on your fuel system) and set all fuel flow rate values to that number.
Don't know. Never changed it. This is unrelated to whether the fuel regulator is or is not controlled by vacuum.
I just put values into my voltage correction chart, as it had the value of just 1.0 throughout the whole chart.
Last time we got it to at least idle, we had to manually zero out the TPS sensor.
Mike-I don't think I got a tuning guide?
Should I take the vacuum line off then and leave the values as a constant?
How about the correction voltage, also as a constant then?
#13
#14
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I have the AEM UEGO, I'll try to get it setup to work with EFI Live tomorrow after class. I'd have it done already but I see it wants a ground so I haven't gotten around to it.
Well I replaced the injectors because I thought I had an issue there, new fuel filter, fuel pressure gauge is reading normal, so I don't think I have a fuel delivery issue.
I put 3.78 into the flow rate chart as they are 30 lb/hr injectors, I used the spreadsheet here: http://www.marcintology.com/tuning/injectors.xls and input 43.5 psi for the fuel pressure. There is where I wonder though do you input idle fuel pressure or WOT pressure? With the racetronix/walbro combo it has 39 psi at idle and 43.5 psi at WOT.
Thanks for all the help and clarification so far, this thing has just been driving me crazy and for a long time.
Well I replaced the injectors because I thought I had an issue there, new fuel filter, fuel pressure gauge is reading normal, so I don't think I have a fuel delivery issue.
I put 3.78 into the flow rate chart as they are 30 lb/hr injectors, I used the spreadsheet here: http://www.marcintology.com/tuning/injectors.xls and input 43.5 psi for the fuel pressure. There is where I wonder though do you input idle fuel pressure or WOT pressure? With the racetronix/walbro combo it has 39 psi at idle and 43.5 psi at WOT.
Thanks for all the help and clarification so far, this thing has just been driving me crazy and for a long time.
#16
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Got the wideband talking to the flashscan today.
Log one with wideband.
Log two with wideband.
So drove the car over an hour and a half today to class and back. Came home, figured out how to get the wideband hooked up to the serial port thanks to the efi live forums.
On the trips to log and see if I got it working correctly the car popped codes for both bank 1 and 2 too rich and IAC RPM too low?
So no codes the last two days but popped them this evening. Believe me car I could have told you its too rich, the cloud of smoke reminds me every time.![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
Also here is another video, I took it this morning, you can hear it backfire.
The backfiring bitch.
This video shows how the rest of the day I have to crank for a long time.
Long crank, needs throttle opened.
Remember now, for some reason the very first time I start the car during the day it starts normal, but the rest of the day no?
Log one with wideband.
Log two with wideband.
So drove the car over an hour and a half today to class and back. Came home, figured out how to get the wideband hooked up to the serial port thanks to the efi live forums.
On the trips to log and see if I got it working correctly the car popped codes for both bank 1 and 2 too rich and IAC RPM too low?
So no codes the last two days but popped them this evening. Believe me car I could have told you its too rich, the cloud of smoke reminds me every time.
![Icon Lol](https://ls1tech.com/forums/images/smilies2/icon_lol.gif)
Also here is another video, I took it this morning, you can hear it backfire.
The backfiring bitch.
This video shows how the rest of the day I have to crank for a long time.
Long crank, needs throttle opened.
Remember now, for some reason the very first time I start the car during the day it starts normal, but the rest of the day no?
#19
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Is the firing order for the coils and injectors been changed to the lt1 firing order seems the ls firing order is diff. Just making sure i had a friend with similar issues after his swap.