993TT Misfire- Help
#48
Rennlist Member
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Are you using s 3.8 bar fuel pressure regulator or 5? I don't know but might be low if using a 5. Also although you may have good pressure, flow might be different (but not sure why there would only be a problem at idle). Are you using a rs pulley on the alternator? What's your voltage at idle?
#49
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Are you using s 3.8 bar fuel pressure regulator or 5? I don't know but might be low if using a 5. Also although you may have good pressure, flow might be different (but not sure why there would only be a problem at idle). Are you using a rs pulley on the alternator? What's your voltage at idle?
#50
Rennlist Member
Thread Starter
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Here are my tests from today:
1-Rented an air compressor and pressurized intake manifold and found no leaks, only air coming out was thru the exhaust valves etc.
2. Cleaned idle stabilizer valve and nothing still runs same.
3. Replaced both 02 sensors with new ones and I get same code. P0130 bank 1 sensor 1. I will get this code towards the end of the day as car starts popping while cruising at idle speeds.
4. Lastly replaced MAF with a used one I had in the garage and get same lean condition at idle with both MAF!! That rules out the MAF issue.
One last thing, when they installed the proto headers I noticed they shrinked exhaust down to like 2.5 inches with some crappy bends. Could this be causing too much back pressure and cause a lean condition at idle?
I sent an email to Todd but have run out of options. Might have to take to a shop for help.
1-Rented an air compressor and pressurized intake manifold and found no leaks, only air coming out was thru the exhaust valves etc.
2. Cleaned idle stabilizer valve and nothing still runs same.
3. Replaced both 02 sensors with new ones and I get same code. P0130 bank 1 sensor 1. I will get this code towards the end of the day as car starts popping while cruising at idle speeds.
4. Lastly replaced MAF with a used one I had in the garage and get same lean condition at idle with both MAF!! That rules out the MAF issue.
One last thing, when they installed the proto headers I noticed they shrinked exhaust down to like 2.5 inches with some crappy bends. Could this be causing too much back pressure and cause a lean condition at idle?
I sent an email to Todd but have run out of options. Might have to take to a shop for help.