Holley 750 DP idle question
I've got a 71 Dart Street/Strip car with a 414 C.I. stroker and a procharger with a Holley HP converted to blow through carb. Been running this set up since 2019 with great results and doing dragweek a lot. The timing is locked at 20 degrees.
Typically this setup idles great in park at 900 and pulls down to about 750-800 when in reverse or drive. Been like that for years and runs great.
Lately the idle is still good at 900 but when you pull it in drive it pulls down to like 550-600 RPM and wants to die. I'm not sure what changed. I recently pulled the carburator and gave it a thorough cleaning. That didn't change anything.
The other day I put on the vacuum gauge, and it only read 5 lbs of vacuum at idle in park. I thought that was odd, so I started adjusting the 4 corner Idle screws until I ended up at around 10 or 11 lbs of vacuum which is more normal for this cam. after revving the engine a few times, I noticed it was back down to 5 or 6 at idle.
Any ideas? It doesn't seem to have a vacum leak and runs great street driving and at the track. It's just idle in gear that is a problem at stop signs.
Any help is appreciated, I've attached a few pics for inspiration.
I've got a 71 Dart Street/Strip car with a 414 C.I. stroker and a procharger with a Holley HP converted to blow through carb. Been running this set up since 2019 with great results and doing dragweek a lot. The timing is locked at 20 degrees.
Typically this setup idles great in park at 900 and pulls down to about 750-800 when in reverse or drive. Been like that for years and runs great.
Lately the idle is still good at 900 but when you pull it in drive it pulls down to like 550-600 RPM and wants to die. I'm not sure what changed. I recently pulled the carburator and gave it a thorough cleaning. That didn't change anything.
The other day I put on the vacuum gauge, and it only read 5 lbs of vacuum at idle in park. I thought that was odd, so I started adjusting the 4 corner Idle screws until I ended up at around 10 or 11 lbs of vacuum which is more normal for this cam. after revving the engine a few times, I noticed it was back down to 5 or 6 at idle.
Any ideas? It doesn't seem to have a vacum leak and runs great street driving and at the track. It's just idle in gear that is a problem at stop signs.
Any help is appreciated, I've attached a few pics for inspiration.