camar0corey

iTrader: (22)

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.





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.

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.

merim123

iTrader: (11)

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?

ahritchie

iTrader: (1)

Hate to say it...go back to optispark factory ignition components and see if it fixes your issues? Or there's always the trusty LS swap fix

355z28

iTrader: (8)

Who did your wiring harness? If its pouring fuel to one side, but leaning out the wrong side couldnt they be messed up in the pinning?

draggin97s10

iTrader: (2)

what does your a/f ratio look like, i firmly believe that it is somewhere in the fueling.

have you tried leaning out your flow chart a little?

camar0corey

iTrader: (22)

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.

draggin97s10

iTrader: (2)

well if it smelled less like gas you were getting somewhere. i havent looked at your data log yet so give me a second.

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.

S10Wildside

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...

• 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.

S10Wildside

For what reason did you not follow the recommended fuel flow settings that were described in the tuning guide received with your 24x purchase?

camar0corey

iTrader: (22)

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.
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?

camar0corey

iTrader: (22)

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.

S10Wildside

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.

S10Wildside

Are you logging the air/fuel ratio with a calibrated wideband O2?

camar0corey

iTrader: (22)

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.

Purple Poncho

iTrader: (1)

Probably fouled out the plugs by now and it is not lighting the mixture properly.

camar0corey

iTrader: (22)

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.

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?

Blackbirdws6

iTrader: (7)

Plugs are probably fouled to all hell with you running very rich. The excess fuel evaporates off the plugs after sitting which likely makes it easier to start.

the_merv

iTrader: (88)

Man I wish I was there to help you get it running..no different from Tuning a LS1.

Turn off EVERYTHING except your VE Table based on the MAP Sensor..get your fuel flow dialed in for the whole range..it will be one set value as mentioned above, and go from there.

Wyocattech

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.

Paul Bell

iTrader: (9)

Exactly what I was thinking.

The folks at EFI Connections are very helpful. Have you spoke to them about this?