Lt1 sounds like a D@$n cannon
06-03-2017, 09:06 AM
#1
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Thread Starter
Join Date: Mar 2017
Location: Ofallon, IL
Posts: 25
Lt1 sounds like a D@$n cannon
So I bought a 94 camaro. V6 car and the previous owner swapped in an LT1 and a t56. It takes around 8 seconds to start and maybe once a day or once a week, its random, it backfires louder than a cannon. I made the mistake of leaving my window down once and it rung my ears for a while. The thing runs perfect after. No idle issues. Maybe gets bad gas mpg but never had another lt1 to compare.
new starter and checked fuel pressure regualtor so those arent it.
Any idea what causes the starting issue? Please help. Bout to get an $200 code reader.
ICM, COIL, WIRES, ETC?
new starter and checked fuel pressure regualtor so those arent it.
Any idea what causes the starting issue? Please help. Bout to get an $200 code reader.
ICM, COIL, WIRES, ETC?
06-03-2017, 09:48 AM
#2
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: Lt1 sounds like a D@$n cannon
Delayed start can often be traced to fuel pressure problems. Attach a pressure test gauge to the Schrader valve, turn key to "run" (not ”start"), pump will prime for two seconds and shut off. Observe fuel pressure at pump shut off, and watch how quickly pressure drops. Should prime to at least 40 PSI, and pressure should not drop rapidly.
What year is the LT1 PCM? If it's OBD-1 (93-95), you don't need a $200 scanner. Discontinued Actron CP9185 is dual OBD-1/OBD-2, and was available (may be sold out) on Amazon for $73. Or, better yet, free download of Scan9495 software, and buy a cable. Pulls codes and can make data logs allowing serious diagnostics of engine operating problems. The author is a member here, and provides timely assistance.
https://www.camaroz28.com/forums/com...95-lt1-874306/
Do not buy an Innova or Equus dual OBD-1/OBD-2 scanner. The LT1 database is corrupt, and they report codes the vehicle does not actually have.
What year is the LT1 PCM? If it's OBD-1 (93-95), you don't need a $200 scanner. Discontinued Actron CP9185 is dual OBD-1/OBD-2, and was available (may be sold out) on Amazon for $73. Or, better yet, free download of Scan9495 software, and buy a cable. Pulls codes and can make data logs allowing serious diagnostics of engine operating problems. The author is a member here, and provides timely assistance.
https://www.camaroz28.com/forums/com...95-lt1-874306/
Do not buy an Innova or Equus dual OBD-1/OBD-2 scanner. The LT1 database is corrupt, and they report codes the vehicle does not actually have.
Last edited by Injuneer; 06-03-2017 at 09:52 AM.
06-03-2017, 10:02 AM
#4
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Thread Starter
Join Date: Mar 2017
Location: Ofallon, IL
Posts: 25
Re: Lt1 sounds like a D@$n cannon
I unhooked the vaccum line on the regulator and no gas came out. I will check it with my gauge however.
would the the fuel pressure cause that huge of a backfire however. Its not an exaggeration. It sounds like a cannon. My muffler would be blown if it wasnst for an exhaust leak.
it actually set off 4 car alarms at my buddies place an made someone call the cops lol.
would the the fuel pressure cause that huge of a backfire however. Its not an exaggeration. It sounds like a cannon. My muffler would be blown if it wasnst for an exhaust leak.
it actually set off 4 car alarms at my buddies place an made someone call the cops lol.
06-05-2017, 10:40 AM
#5
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: Lt1 sounds like a D@$n cannon
If the injectors are leaking, bleeding off the fuel pressure, it could cause fuel to build up in the exhaust. There are several different things that can cause pressure bleedoff when the pump shuts down. A leaking diaphragm in the fuel pressure regulator, allowing fuel into the vacuum line is only one of them. That's why you have to check the fuel pressure.