[Sick335]

Hey guys,

Thanks in advance for your humble opinions.
I've read some threads on this, and came to a conclusion that it is most likely my fuel pump(i do have Terrys walbro inline pump upgrade).
The car is throwing the 29DC code every time i give it more than 20% throttle. Car shakes, and shortly after, stalls. While the car is cold, it is somewhat drivable, and i can make a 10-15 mile drive in it, but after it warms up it dies as soon as i touch the throttle.
I changed out the coils, spark plugs, and the low pressure fuel sensor, yet the problem persists. All i can think is that the walbro went bad? Even tho i installed it less than 6 months ago, and have driven the car maybe 5000 miles since the install.

Any ideas?

[Ingeniator]

Originally Posted by Sick335

Hello Fellas,

Thanks in advance for your humble opinions.
I've read some threads on this, and came to a conclusion that it is most likely my fuel pump(i do have Terrys walbro inline pump upgrade).
The car is throwing the 29DC code every time i give it more than 20% throttle. Car shakes, and shortly after, stalls. While the car is cold, it is somewhat drivable, and i can make a 10-15 mile drive in it, but after it warms up it dies as soon as i touch the throttle.
I changed out the coils, spark plugs, and the low pressure fuel sensor, yet the problem persists. All i can think is that the walbro went bad? Even tho i installed it less than 6 months ago, and have driven the car maybe 5000 miles since the install.

Any ideas?

Check your TPS sensor or pedal. You have a deviation that is limiting your throttle output to the ecm.

EDIT: Scratch that. I believe I have my codes mixed up and that is actually injection cylinder switch off?. I would suggest you check your high side fuel pressure sensor. If this is good then it is your HPFP not the low side LPFP or booster. If you have a cobb, JB etc. to log with that is probably your cheapest method of troubleshooting unless your still under warranty.

[Sick335]

Originally Posted by Ingeniator

Check your TPS sensor or pedal. You have a deviation that is limiting your throttle output to the ecm.

EDIT: Scratch that. I believe I have my codes mixed up and that is actually injection cylinder switch off?. I would suggest you check your high side fuel pressure sensor. If this is good then it is your HPFP not the low side LPFP or booster. If you have a cobb, JB etc. to log with that is probably your cheapest method of troubleshooting unless your still under warranty.

Thanks for the input, i cant log, as theres nothing TO log. As soon ad i give it more than 20% throttle it goes into cylinder switch off mode and stalls... It's probably the hpfp

[Sick335]

Too much input guys, please slow down

[dicostal]

I do not know about the code, but symptoms sound like a bad injector. When you changed the spark plugs did you notice any of them darker than the others?

[Sick335]

Originally Posted by dicostal

I do not know about the code, but symptoms sound like a bad injector. When you changed the spark plugs did you notice any of them darker than the others?

I believe spark plug #5 was a little darker, but nothing crazy.

[boostaholic786]

I'm having the EXACT same issue your having. Injection cylinder switch off. I changed my plugs to see if that helped and I guess move on to coil packs since it doesnt give me a specific cylinder This is what I cant stand though...Start throwing parts at it not knowing if its going to be fixed or not. The car ran completely fine with the stock LPFP and about 8 gallons E85, 4 gallons 93. As soon as I installed, or my buddy installed the Walbro drop in 465LPH fuel pump, this issue comes up immediately. We even went to the extent of taking the fuel pump back out, checking all the lines, making sure everything was perfect and thought it was a faulty pump. I was pissed so we tried my buddy who has a perfectly good walbro 455lph AND SAME SHIT!!! So I have been trying to diagnose this issue FOREVER and am on a mission to make sure I figure this shit out!!!

[Sick335]

Originally Posted by boostaholic786

I'm having the EXACT same issue your having. Injection cylinder switch off. I changed my plugs to see if that helped and I guess move on to coil packs since it doesnt give me a specific cylinder This is what I cant stand though...Start throwing parts at it not knowing if its going to be fixed or not. The car ran completely fine with the stock LPFP and about 8 gallons E85, 4 gallons 93. As soon as I installed, or my buddy installed the Walbro drop in 465LPH fuel pump, this issue comes up immediately. We even went to the extent of taking the fuel pump back out, checking all the lines, making sure everything was perfect and thought it was a faulty pump. I was pissed so we tried my buddy who has a perfectly good walbro 455lph AND SAME SHIT!!! So I have been trying to diagnose this issue FOREVER and am on a mission to make sure I figure this shit out!!!

I hope you figure it out soon. I'm replacing my fuel pump and the injectors, so if it doesnt do the trick, i will have no idea what to do next.

[09E90utah]

Originally Posted by Sick335

I hope you figure it out soon. I'm replacing my fuel pump and the injectors, so if it doesnt do the trick, i will have no idea what to do next.

I had something similar when I went to the back-end flash. I had all the settings right for my G5 ISO and it still did it. So I reloaded the firmware into the G5 then reset defaults and everything cleared up. Just a thought.

[Sick335]

Originally Posted by 09E90utah

I had something similar when I went to the back-end flash. I had all the settings right for my G5 ISO and it still did it. So I reloaded the firmware into the G5 then reset defaults and everything cleared up. Just a thought.

Just turned my car in to the dealer to get injectors replaced. I'll try resetting the flash after i get it back. Thanks for the advice

[09E90utah]

Originally Posted by Sick335

Just turned my car in to the dealer to get injectors replaced. I'll try resetting the flash after i get it back. Thanks for the advice

Did you remove the G5 and back-end flash before you took it to the dealer? If so, was it still doing the same thing?

[Sick335]

Originally Posted by 09E90utah

Did you remove the G5 and back-end flash before you took it to the dealer? If so, was it still doing the same thing?

no i didnt, i have a pretty cool SA.

[135Pats]

Whenever fuel cuts that abruptly (assuming that is the issue itself, and not merely the resulting outcome of an unrelated problem) I usually look to the high pressure side. Low pressure issues usually involve crappy starts and breaking up, not outright fuel shutoff.