'93 Vette SURGES with AC on!!!

Reply Subscribe

Thread Tools

Search this Thread

Jul 25, 2003 | 11:41 PM

GRNVNM93

Thread Starter

Melting Slicks

Joined: Apr 2002

Posts: 3,024

Likes: 1

From: Naples FL

'93 Vette SURGES with AC on!!!

I've noticed recently that with the AC on and at constant rpm (like 1500) the car kinda drops back and surges forward.. not very drastic, but noticeable... What's the deal? Only does this with the AC on.... Something as basic as a new plugs/wires? Anyone else have this happen to theirs??

Jul 26, 2003 | 12:15 AM

don hall

Safety Car

Joined: Aug 2002

Posts: 3,842

Likes: 230

From: SANTA CRUZ CA

Re: '93 Vette SURGES with AC on!!! (GRNVNM93)

Your RPMs will drop slightly when the A/C compressor cycles on. Is your surge in sync with the compressor cycling?

Jul 26, 2003 | 12:20 AM

GRNVNM93

Thread Starter

Melting Slicks

Joined: Apr 2002

Posts: 3,024

Likes: 1

From: Naples FL

Re: '93 Vette SURGES with AC on!!! (Oldman)

Quote:

Your RPMs will drop slightly when the A/C compressor cycles on. Is your surge in sync with the compressor cycling?

I'd assume so, as the surges are in a rythm. But these surges are a lot more noticeable as of lately. :confused:

Jul 26, 2003 | 01:55 PM

GRNVNM93

Thread Starter

Melting Slicks

Joined: Apr 2002

Posts: 3,024

Likes: 1

From: Naples FL

Re: '93 Vette SURGES with AC on!!! (GRNVNM93)

Anyone with any ideas?

Jul 26, 2003 | 02:36 PM

Lone Ranger

Le Mans Master

Joined: Feb 2002

Posts: 7,858

Likes: 2

Re: '93 Vette SURGES with AC on!!! (GRNVNM93)

Quote:

Anyone with any ideas?

Its just your compressor cycling. Make sure A/C is fully charged with R12 or 134a, whichever. Low freon over time will make the compressor a tougher accessory to spin.

Jul 26, 2003 | 04:09 PM

don hall

Safety Car

Joined: Aug 2002

Posts: 3,842

Likes: 230

From: SANTA CRUZ CA

Re: '93 Vette SURGES with AC on!!! (GRNVNM93)

Quote:

Your RPMs will drop slightly when the A/C compressor cycles on. Is your surge in sync with the compressor cycling?

I'd assume so, as the surges are in a rhythm.....

To determine if the compressor is causing the engine surge, idle the engine with the A/C "on", raise the hood and watch the clutch engage the compressor. If the RPMs drop (which they should) when the clutch engages the compressor, and resume to normal when the clutch disengages, you will know the source of the problem. If the engine surges regardless of the clutch engaging the compressor, you have another problem.

Reply Subscribe