Sometimes LT1 Engine Rpm takes sharp drop?
Thread Starter
Racer
Joined: Mar 2005
Posts: 285
Likes: 0
From: Keller Texas
Sometimes LT1 Engine Rpm takes sharp drop?
Driving down road 2000-3000 rpm coming toward stop sign or light, push in clutch and sometimes engine rpm takes nose dive to 500-600 then dies. Other times I do the same thing and rpm will slowly go down to and nicely set at 750-800. I am going to computer idle raised to 850. But I know this is not the answer because one of the chips i have tried does have idle set at 850So I now bring the rpm with car in gear so i dont take chance of stall. This happens with chips from 2 different tuners so i think It is more the engine and not the tune. IAC? not adjusting quick changes?
93 lt1 383 lt4 hot cam ported heads
93 lt1 383 lt4 hot cam ported heads
Last edited by 66grandsport; Feb 17, 2009 at 09:05 AM.
1st Gear
Joined: Jun 2014
Posts: 1
Likes: 0
same issue
Mine is really random it goes up through the gears fine but randomly when I downshift. push in the clutch and the RPM's just drop from under it and it will stall. It could be from 6th gear to 5th or 3rd to 2nd with no rhyme or reason. I would love to hear what you figured out. Other times it drives great. I can shift into neutral and roll to a stop sign with no problems.
Thanks in advance
Kris
Racer
Joined: Oct 2011
Posts: 270
Likes: 15
From: Benching 455RAW Texas
Did you ever find out your solution to this problem. I just bought a 67 camaro with an LT1 - 6speed and have the exact same issue as you do. I have been racking my brain trying to figure it out.
Mine is really random it goes up through the gears fine but randomly when I downshift. push in the clutch and the RPM's just drop from under it and it will stall. It could be from 6th gear to 5th or 3rd to 2nd with no rhyme or reason. I would love to hear what you figured out. Other times it drives great. I can shift into neutral and roll to a stop sign with no problems.
Thanks in advance
Kris
Mine is really random it goes up through the gears fine but randomly when I downshift. push in the clutch and the RPM's just drop from under it and it will stall. It could be from 6th gear to 5th or 3rd to 2nd with no rhyme or reason. I would love to hear what you figured out. Other times it drives great. I can shift into neutral and roll to a stop sign with no problems.
Thanks in advance
Kris
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Happens when you use the search feature. Sometimes don't notice the date of the original post.
Try checking the fuel pressure regulator. If it is bad, it could cause something like this to happen. Does it drop and stall if you rev it in neutral without pushing the clutch in?
If it does it ONLY when you push in the clutch, the only thing i can really come up with is that either your pivot stud is worn and the fork is hitting the PP, but that creates a banging noise. Or your throw out bearing may be bad?
On second thought, maybe the Idle Air Control, or the throttle position sensor may be going? assuming of course that your LT1 is stil SFI and PCM controlled. That or a vacuum leak.
Did you ever find out your solution to this problem. I just bought a 67 camaro with an LT1 - 6speed and have the exact same issue as you do. I have been racking my brain trying to figure it out.
Mine is really random it goes up through the gears fine but randomly when I downshift. push in the clutch and the RPM's just drop from under it and it will stall. It could be from 6th gear to 5th or 3rd to 2nd with no rhyme or reason. I would love to hear what you figured out. Other times it drives great. I can shift into neutral and roll to a stop sign with no problems.
Thanks in advance
Kris
Mine is really random it goes up through the gears fine but randomly when I downshift. push in the clutch and the RPM's just drop from under it and it will stall. It could be from 6th gear to 5th or 3rd to 2nd with no rhyme or reason. I would love to hear what you figured out. Other times it drives great. I can shift into neutral and roll to a stop sign with no problems.
Thanks in advance
Kris
If it does it ONLY when you push in the clutch, the only thing i can really come up with is that either your pivot stud is worn and the fork is hitting the PP, but that creates a banging noise. Or your throw out bearing may be bad?
On second thought, maybe the Idle Air Control, or the throttle position sensor may be going? assuming of course that your LT1 is stil SFI and PCM controlled. That or a vacuum leak.
