stuttering in 6th gear
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Joined: Jul 2011
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From: Palm City FL
stuttering in 6th gear
I have a 1996 LT4 that will not accelerate in 6th gear. The symptom is for lack of a better definition stuttering. I do not have any codes thrown and 1-5 seem to perform normally, however when the temperature exceeds 210 I get random misfire codes.
I have new injectors, plugs and wires. Any ideas would be helpful. I suspect the opti, but heat can effect many things.
P0300
I have new injectors, plugs and wires. Any ideas would be helpful. I suspect the opti, but heat can effect many things.
P0300
Last edited by starfire54; Mar 31, 2013 at 10:38 AM.
Team Owner
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From: altered state
St. Jude Donor '05
post the codes up maybe someone can help.
So many good deals on LT1 cars..but god that stinking lousy pos ignition $y$tem they have keeps me from owning one. What an abortion of a design. Nice followup to the flop of the CFI and TPI intakes lol.
So many good deals on LT1 cars..but god that stinking lousy pos ignition $y$tem they have keeps me from owning one. What an abortion of a design. Nice followup to the flop of the CFI and TPI intakes lol.
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From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
There are far more of them out there without any issues at all than ones having problems.
Jut over 120k miles on mine now, without any issues.
Still has the factory original Opti.
Team Owner
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From: altered state
St. Jude Donor '05
Dont get me wrong they run great with some mods and drive way better than the early C4s...drove a 93 with EVERYthing new from bumper to bumper after i sold my Z...new msd opti too.
On a hot summer day sitting in traffic occasionally it would start that random slight miss business or typical opti stuff. That and they run so hot lol. I was just waiting for the thing to die. It didnt but shook my trust.
Those cars just arent for me dont trust em.
On a hot summer day sitting in traffic occasionally it would start that random slight miss business or typical opti stuff. That and they run so hot lol. I was just waiting for the thing to die. It didnt but shook my trust.
Those cars just arent for me dont trust em.
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From: Palm City FL
I neglected to include all of my attempts. I double checked the gaps and even had a mechanic friend verify the gaps, replaced the fuel filter the day I bought the car only 20 miles or so on the filter, check fuel pressure, but have not when the car is hot (which I will), new injectors form John (FIC), new Taylor wires, NGK Iridium plugs. I will check for vacuum leaks.
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Race Director
Joined: Jan 2005
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From: Slidell Louisiana
Dont get me wrong they run great with some mods and drive way better than the early C4s...drove a 93 with EVERYthing new from bumper to bumper after i sold my Z...new msd opti too.
On a hot summer day sitting in traffic occasionally it would start that random slight miss business or typical opti stuff. That and they run so hot lol. I was just waiting for the thing to die. It didnt but shook my trust.
Those cars just arent for me dont trust em.
On a hot summer day sitting in traffic occasionally it would start that random slight miss business or typical opti stuff. That and they run so hot lol. I was just waiting for the thing to die. It didnt but shook my trust.
Those cars just arent for me dont trust em.
The vented optis ROCK>>>>>
Race Director
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From: Slidell Louisiana
On my OBDII impala .. I kept getting misfire codes after a tune up.
Chased it for months until I put factory wires back on it. for some resaon it did not like the high dollar aftermarket wires.
Mike
Chased it for months until I put factory wires back on it. for some resaon it did not like the high dollar aftermarket wires.
Mike
Melting Slicks
Joined: Sep 2008
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From: Cherokee National Forest TN
At what RPM or vehicle speed does the problem occur?
If running on a flat stretch of road 6th gear is used after 65mph with a 3.33 R&P.
High load + low RPM equates to engine bucking or luggng & is bad for piston skirts.
If running on a flat stretch of road 6th gear is used after 65mph with a 3.33 R&P.
High load + low RPM equates to engine bucking or luggng & is bad for piston skirts.
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From: Palm City FL
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From: Slidell Louisiana
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From: shapleigh maine
6th gear is a .5 to 1 overdrive. I can't use 6th on my car below 65 mph. Too much overdrive, and I have a 4.10 rear gear. I suspect that you are engaging 6th too early causing an engine stumble.
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From: Slidell Louisiana
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From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
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From: Miami Florida
I think you're just getting on 6 way too early. I believe the LT4s are 3.45 stock. I know I only get on 6 at around 70. If that doesn't do it double check the heat range on you plugs. I doubt it's opti. Was the problem present before your tuneup?
Melting Slicks
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From: Cherokee National Forest TN
Burning Brakes
Joined: Nov 2010
Posts: 855
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From: Crystal Springs MS
I have a 1996 LT4 that will not accelerate in 6th gear. The symptom is for lack of a better definition stuttering. I do not have any codes thrown and 1-5 seem to perform normally, however when the temperature exceeds 210 I get random misfire codes.
I have new injectors, plugs and wires. Any ideas would be helpful. I suspect the opti, but heat can effect many things.
P0300
I have new injectors, plugs and wires. Any ideas would be helpful. I suspect the opti, but heat can effect many things.
P0300
'96 LT4, 123K miles - I drive around 2000, 2500 highway miles a month in this car, it's my 'work' car, and I know it well. Back in January I noticed my highway gas mileage was dropping from 30mpg down to around 27, 28mpg. Around middle of February I started noticing a slight stutter/shudder when climbing hills and inclines on the highway, and speed would drop a couple of MPH - it's never done that before.
We pulled out the Tech2...misfires. The misfire graph lit up like a checkerboard @ 65-70mph, only random while driving in town and at lower speeds. After checking injectors, wires, plugs, ICM/coil and fuel pressure I bit the bullet and ordered an Opti. I expected to see evidence of arcing and an eat-up rotor but surprisingly they were in decent shape. The bearing on the shaft had given out and there was significant 'wobble' in it. Amazing thing, it never threw a code. Replaced the Opti and now the ol' girl is back!
RollaMo, the mileage on mine was 123,998 miles at the swap...2 miles short of 124k.
Last edited by Phat98; Apr 4, 2013 at 12:24 PM.