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Cobalt turned Goblin throttle issues

331 Views 3 Replies 3 Participants Last post by  Robf
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Hello everyone I'm a fairly new cobalt owner. I decided to build a df goblin using a 2007 chevy cobalt ls 2.2l f35 5 speed donor. The car is now a legal goblin in the state of Iowa. I'm having some issues and I'm hoping this group will be able to help me sort it out. I've asked on goblin forums and no one else has had this problem.

I have had an issue with my goblin bogging down when my foot is to the floor in 1st and 2nd gear. The only check engine lights I have were the evap and 2nd 02 sensor as I'm running an afr gauge. I sent the ecu off to get tuned and remove the torque limits, increase rpm redline, remove check engine lights that are common with the goblin etc. I got it back and it feels better but again from like 3rd gear on. Ill attach some live data. It still seems like the throttle body isn't opening up like it should until I hit 3rd gear. When you launch it in first or second initially it feels like the butterfly wants to open but it just doesn't then it bogs down and does the same thing as stated above.

The throttle position data seems weird as the whole time my foot was buried unless I was shifting. 3rd and 4th feel like an entirely different animal just trying to get the other gears to do the same. I did a rolling start in third gear and the throttle opened the whole time nearly 100 percent. It doesn't matter how fast I'm going but if I'm in any gear other than 1st and 2nd it goes. What would the computer be sensing to say not to open the throttle more than 50 percent if I'm in 1st or 2nd but wide open as soon as I'm in third no matter the speed I'm going. Again no check engines and it doesn't sound like the transmission is slipping in 1st and 2nd. I did put a new clutch,flywheel, slave cylinder, master cylinder,timing chain kit and waterpump in when i was putting the car together. I wouldn't think even if those parts were installed incorrectly that it would affect the only 1st and 2nd and also make the throttle body not open vs just slipping the tranny.

When key is on I can get the throttle to match foot position in every gear clutch in or clutch out.
When running I can get the throttle to match foot position in neutral, clutch in in 1st and 2nd as well as clutch out full throttle under load in 3rd 4th 5th and reverse.

When under load in 1st and 2nd throttle opens to 30 to 50 percent but that's about it.

I have an appointment to do a live tune at the end of April but was hoping someone on the forum can point me in a direction before then.

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@Robf Sorry I don't have a solution or advice for you but would love to check out your Goblin. Shoot me a message if you are in the CR area or are bringing it to a show or meet.
Lonny can’t give you any ideas? Seems strange.
Lonny can’t give you any ideas? Seems strange.
Hey I got it figured out for whatever reason the brake torque limits were being hit so the computer wasn't opening the throttle body fully. I used hp tuners to shut it off and boom she runs good now!
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