Efi code 15

[twister01]

I have tried the search and so far not coming up with anything.
A little about my set up 351w ford lighning upper and lower plenums. motorsport 70 mm throttle body ,24 pound injectors , summit 70 mm MAF summit pro billet TFI distributor Rjm harness A9S computer msd streetfire tfi coil. I have checked fuel pressure and is steady 37pounds at idle and 42 WOT. with it running at idle it is fine if you bring it up to 2200 or higher it will get a surge like it lost power for a sec. then comes right back up. I put a volt meter on my main power wire off the battery and it stays right at 14.1 volts even when it surges. Is there a way to check tfi coil wires for steady spark or volts??? Any ideas are greatly appreciated. Dave

 

[slow poke]

2200 rpm is a bit high for an O2 sensor issue, but the stumble could be from old sensors? Just a thought..............

 

[twister01]

New bosh o2 sensors , all the sensors are new .the code says (power interruption to computer memory or etc),but the main harness 12volt wire never looses power. I have checked all the ground wires from engine to body, engine to frame etc .

 

[ransil]

I found Code 15 Keep Alive Memory Test failure. maybe from a battery disconnect. reset codes and see if it comes back

does not seem related to your problem , maybe a dead spot in your TPS sensor

 

[twister01]

I have cleared the codes a couple times, the tps is set @ .98 and seems to be smooth as I open throttle. Is there a way to check the tps ?? maybe I should try and get another one and try it. this one is a new motorsport that I am running. I have set the tps as per some of the searches I did on the site. thanks for the input, Dave

 

[Broncobowsher]

Memory failure. Any aftermarket chip in it?
Next, open the computer and look for burned traces and/or swelled caps. Fix the issue and trace back to the pin they are connected to and fix the issue with that pin.
If those are not the issue, you really do have a fried computer.
That's just for the Code 15.

If the surge is still there, get a proper tune. You have a computer running and engine that is significantly larger then it was originally programmed for, running a MAF that is feeding it lies, squirting injectors that are larger then it is programmed for. You are probably outside what the tuning can accept.

 

[twister01]

I am running a tweecer and a tune from Mike. I will open the computer and take a look to see if I can see anything.I will take a pic also , thanks Dave

 

[Broncobowsher]

OK, with the chip the code is correct. The memory failure is correct since it is running the memory off the chip instead of the internal memory.

At this point it is probably just the need for a little fine tuning of the programming.

 

[ransil]

I have cleared the codes a couple times, the tps is set @ .98 and seems to be smooth as I open throttle. Is there a way to check the tps ?? maybe I should try and get another one and try it. this one is a new motorsport that I am running. I have set the tps as per some of the searches I did on the site. thanks for the input, Dave

for dead spots in the TPS I use a multimeter that has a min max setting and just slowly turn the TPS from off to WOT, setting is ohms and TPS is out of the vehicle. any non linear measurement could be a dead spot.

 

[twister01]

ok, I have checked tps out of housing. it is smooth and I think its ok . the black wire coming out of the tps plug doesn't show ground I had to probe it and tie alligator clip to ground. this seems like it may be a problem. I put it all back in reset tps and left ground probed and ground clips attached and still got the drop in engine. Is there a way to check tfi wires coming out of tfi coil to see if that's where I am loosing spark (power)???? Dave

 

[Viperwolf1]

What codes does it show now and are they KOEO or KOER?

 

[twister01]

Code 15 ,and reg soft codes .KoEo, I am going to try checking the red 12v wire going to coil to see if it drops power while running.

 

[twister01]

Ok power at red wire on coil stays @12.2 volts and higher while engine is running, and still will lose power and die, Green wire at coil same 12.2 volt and up and still will lose power and die. So I have fuel and power to coil at all times while running.

 

[Viperwolf1]

Code 15 ,and reg soft codes .KoEo, I am going to try checking the red 12v wire going to coil to see if it drops power while running.

Are you not able to get KOER codes?

 

[twister01]

ok just ran a KOER test while running the test it died twice , codes are 94 ,converter clutch control circuit failure. 44 thermactor air system fault .12 rpm at idle out of range/high.

 

[Viperwolf1]

Do a base idle reset. Make sure throttle body, IAC and MAF are clean first.

 

[twister01]

I will go back out and clean parts and reset idle. thanks Dave

 

[twister01]

I cleaned parts , reset base idle and so far it seems ok ran a KOER test came back no DTC .ran a KOEO test came back just normal soft codes .So I will try and get it out and drive it and see how it does. thank you for all your help and advice,Dave

 

[twister01]

I took it out for a drive and didn't make it to the end of the street. Idle would surge then come right back . keep driving and it kept repeating surge and try to die. I brought it home ran a KOER test came back with 43 and 94 again. I am not sure what to do now ! Dave

 

[Viperwolf1]

I took it out for a drive and didn't make it to the end of the street. Idle would surge then come right back . keep driving and it kept repeating surge and try to die. I brought it home ran a KOER test came back with 43 and 94 again. I am not sure what to do now ! Dave

43 - o2 Sensors indicate lean at Full Throttle

Make sure you have the harness O2 connectors on the correct sides.