Trouble at 4000 rpm
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Trouble at 4000 rpm
I'm working on a 94 Z26 with the 3100 that has an odd problem.  It seems to run well but if you take it to 4000 rpm in neutral (or under load) the engine starts to run real bad.  Under load it backfires a little.  When you let off of the accelerator it sometimes makes a 'bang' around 2000 rpm. It's a loud metallic noise.
I haven't been able to pin-point the problem and it's driving me nuts.  It's got new plugs, wires, and fuel filter.
Any ideas?
I haven't been able to pin-point the problem and it's driving me nuts.  It's got new plugs, wires, and fuel filter.
Any ideas?
The Kids: Fast and Faster.


- Mr Goodwrench
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- Location: Wis
Trouble at 4000 rpm
Seems kinda odd any codes??
almost sounds like a bad lifter,push rod or rocker arm. even a broken or bent valve..
pluged or bad egr valve?? bad cat?? bad or warren out or leaky fuel injector or regulator gowing..
got me stumped
Mr Goodwrench
almost sounds like a bad lifter,push rod or rocker arm. even a broken or bent valve..
pluged or bad egr valve?? bad cat?? bad or warren out or leaky fuel injector or regulator gowing..
got me stumped
Mr Goodwrench
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Trouble at 4000 rpm
(Mr Goodwrench @ Jun. 19 2006,22:49)Q
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ESeems kinda odd any codes??
almost sounds like a bad lifter,push rod or rocker arm. even a broken or bent valve..
pluged or bad egr valve?? bad cat??  bad or warren out or leaky fuel injector or regulator gowing..
got me stumped
Mr Goodwrench
Yeah, it's a puzzler.
No codes so that's a bummer.
I'm thinking of pulling the top end and having a look because I'm thinking push rod or lifter. Never thought about the rocker arm...good idea.
U
O
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ESeems kinda odd any codes??
almost sounds like a bad lifter,push rod or rocker arm. even a broken or bent valve..
pluged or bad egr valve?? bad cat??  bad or warren out or leaky fuel injector or regulator gowing..
got me stumped
Mr Goodwrench
Yeah, it's a puzzler.
No codes so that's a bummer.
I'm thinking of pulling the top end and having a look because I'm thinking push rod or lifter. Never thought about the rocker arm...good idea.
The Kids: Fast and Faster.


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Trouble at 4000 rpm
In neutral and park the 3100 is programmed to not go over an RPM that is close to 3500-4000. You might look into that.
Rex Weatherford
92 Beretta GTZ Quad4 Turbo / 5-speed (sold)
Best 1/4 ET =  13.523 @ 105.16 mph
07 Mazda 5 Black on Black (it's slow)
92 Beretta GTZ Quad4 Turbo / 5-speed (sold)
Best 1/4 ET =  13.523 @ 105.16 mph
07 Mazda 5 Black on Black (it's slow)
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Trouble at 4000 rpm
can you get it over 4000 rpm when driving? Im thinking maybe the park/neutral switch or something else that tells the system its allowed to rev over 4000 rpm.
94 Beretta Z26 57,4xx miles
3100, auto, crank windows, power locks/trunk, A/C,
To many mods to list
-intercooler
Among beretta boards
1st Turbo 4t60-e
1st Turbo 3100
1st Turbo Z26
1st 94+ Turbo
3100, auto, crank windows, power locks/trunk, A/C,
To many mods to list
-intercooler

Among beretta boards
1st Turbo 4t60-e
1st Turbo 3100
1st Turbo Z26
1st 94+ Turbo
- Mr Goodwrench
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- Joined: Thu Feb 09, 2006 8:21 pm
- Location: Wis
Trouble at 4000 rpm
correct it does have a rev limiter in park an neut. thinking 3,800 to 4,200 rpms. it may back-fire a little
but it shouldnt be banging..
Mr Goodwrench
but it shouldnt be banging..
Mr Goodwrench
- KFLO 93 GT
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Trouble at 4000 rpm
Sounds like a cat plugging up, or breaking apart to me. Gotten a good whif of the exhaust lately?

93 GTs
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Trouble at 4000 rpm
(KFLO 93 GT @ Jun. 26 2006,11:30)Q
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ESounds like a cat plugging up, or breaking apart to me.  Gotten a good whif of the exhaust lately?
Yeah, that's what I'm thinking. Even though it's only a year or so old, it certainly smells like a bad cat. Phew.
U
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ESounds like a cat plugging up, or breaking apart to me.  Gotten a good whif of the exhaust lately?
Yeah, that's what I'm thinking. Even though it's only a year or so old, it certainly smells like a bad cat. Phew.
The Kids: Fast and Faster.


- Mr Goodwrench
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- Location: Wis
Trouble at 4000 rpm
if it only a year old and gone bad check to see if it has any warranty. most cats have a 1-5 year on them..
Mr Goodwrench
Mr Goodwrench