LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Very weak engine

Thread Tools
 
Search this Thread
 
Old Sep 26, 2017 | 04:09 PM
  #1  
Shoedog's Avatar
Thread Starter
Registered User
 
Joined: Sep 2017
Posts: 5
Very weak engine

I just bought a 93 z28 manual trans. 70k miles. The car doesn't pull anywhere close to what it should. Struggles to rev past 3800-4000 rpm. It starts great and never dies, it's just weak. It is totally stock. Any ideas more than welcome.
Old Sep 26, 2017 | 04:46 PM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: Very weak engine

What happens when it hits 3,800-4,000 RPM - misfires, total loss of power, or keeps running, but just won’t go past 4,000?

Has it been checked for a plugged catalytic converter?

At any point have you scanned it for codes, or checked the fuel pressure?
Old Sep 26, 2017 | 05:46 PM
  #3  
Shoedog's Avatar
Thread Starter
Registered User
 
Joined: Sep 2017
Posts: 5
Re: Very weak engine

The car runs past 4000, it's just sluggish. Revs build slow.
I haven't checked anything (bought it last night). I will start a checklist of your suggestions. Thank you!
Old Sep 26, 2017 | 09:56 PM
  #4  
shoebox's Avatar
Registered User
 
Joined: Dec 1969
Posts: 27,728
From: Little Rock, AR
Re: Very weak engine

A weak coil can also cause weak performance.
Old Sep 26, 2017 | 10:05 PM
  #5  
Shoedog's Avatar
Thread Starter
Registered User
 
Joined: Sep 2017
Posts: 5
Re: Very weak engine

Is there a way to test the coil?
thanks guys
Old Sep 30, 2017 | 02:25 PM
  #6  
Shoedog's Avatar
Thread Starter
Registered User
 
Joined: Sep 2017
Posts: 5
Re: Very weak engine

SOLVED. The fuel was over a year old. I drained the tank and put in premium. HUGE difference. Thanks for the input y'all.
Old Sep 30, 2017 | 02:48 PM
  #7  
Chimera96's Avatar
Registered User
 
Joined: Jun 2003
Posts: 1,115
Re: Very weak engine

consider changing the fuel filter now




All times are GMT -5. The time now is 01:15 AM.