Back Fire when Accelerating

Reply Subscribe

Thread Tools

Search this Thread

Jan 6, 2020 | 08:29 AM

RNAVDAVE

Thread Starter

Instructor

Joined: Aug 2013

Posts: 124

Likes: 0

From: Buckhead GA

Back Fire when Accelerating

I have a 94 LT1 that pops in the intake when accelerating fast. If I simply ease on the gas no pop. Engine runs perfectly smooth at idle and at higher RPM and only pops on hard acceleration. All plug wires are correct and none crossed and it has a new Opti Spark on it. Anyone ever had this issue.

Jan 6, 2020 | 09:04 AM

Tom400CFI

Team Owner

Joined: Aug 2004

Posts: 21,543

Likes: 3,216

From: Park City Utah

Check your fuel pressure when the symptom is occurring. -When accelerating fast.

Jan 6, 2020 | 09:11 AM

RNAVDAVE

Thread Starter

Instructor

Joined: Aug 2013

Posts: 124

Likes: 0

From: Buckhead GA

Thanks I will check that. Car also has new fuel pump and filter.

Jan 6, 2020 | 09:44 AM

Kevova

Le Mans Master

Joined: Sep 2013

Posts: 6,192

Likes: 750

From: near the thumb in the mitten

Codes? Vacuum leaks, air leaks between MAF sensor and throttle body. MAF film contamination from over oiled air filter. You could try MAF cleaner. While you are make sure throttle body bores are clean just maintenance.

Jan 6, 2020 | 10:04 AM

fake

Safety Car

Joined: Jan 2004

Posts: 4,549

Likes: 343

From: Glastonbury CT

My 1993 opti failed when hard accelarating! What did you use for a replacement ? Did you change your water pump? Did you seal the unit after installing with Marine clear caulk? Any codes? How much mileage on this beast?

Jan 6, 2020 | 03:30 PM

RNAVDAVE

Thread Starter

Instructor

Joined: Aug 2013

Posts: 124

Likes: 0

From: Buckhead GA

Yes water pump was replaced and Opti came from Summit Racing, there are no codes.

Jan 6, 2020 | 03:51 PM

FAUEE

Race Director

Joined: Oct 2012

Posts: 17,382

Likes: 6,526

From: Melbourne, FL

Are you sure it's in the intake and not just the exhaust popping? If it's running a little rich you might get some popping and cracking out the exhaust.

Jan 6, 2020 | 06:21 PM

fake

Safety Car

Joined: Jan 2004

Posts: 4,549

Likes: 343

From: Glastonbury CT

Was the opti a MSD from Summitt? Mine shown no codes that made any sense. No warning just got worse ! Place some mileage on it and see if it gets worse. Some times the rotor screws get loose if they do not Blue Lock tite them.. Could be the china wall in rear leaking, look for oil deposits near the intake!