help please, does 86 roc have computer
Thread Starter
Member
Joined: Mar 2008
Posts: 251
Likes: 1
From: South Carolina
Car: 1986 Iroc-Z
Engine: 355 Phase 2 Bowtie heads
Transmission: 700r4
Axle/Gears: 342
help please, does 86 roc have computer
i have an 86 iroc that came with a 305 carb. i now have a slighty modified 350 and i'm having major issues.
my car runs like a champ except at 5000 rpm's. once i reach that rpm the car will start skipping and popping.
to the best of my knowledge the computer shouldnt be hooked up, but the car redlines at 5000 rpms and that is where my car starts skipping and popping.
could the computer be giving me a problem?
my car runs like a champ except at 5000 rpm's. once i reach that rpm the car will start skipping and popping.
to the best of my knowledge the computer shouldnt be hooked up, but the car redlines at 5000 rpms and that is where my car starts skipping and popping.
could the computer be giving me a problem?
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
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Some third gens are equipped with a vehicle speed limiter which prevents attaining top speed.
However, most of them are were the high winding 305 TBIs.
Z28s and other TPIs are not equipped with a limiter.
The limiter should function in top gear, not neutral.
A well tuned engine will sound beautiful at 5000 RPM.
It sounds like you have an ignition problem.
An oscilloscope would tell you allot in this case.
Happy Racing!
If People Drove Any Slower Theyd Be Going BackwardsHow bout those dorks too scared to drive without headlights in the daytime!
.
Thread Starter
Member
Joined: Mar 2008
Posts: 251
Likes: 1
From: South Carolina
Car: 1986 Iroc-Z
Engine: 355 Phase 2 Bowtie heads
Transmission: 700r4
Axle/Gears: 342
Re: help please, does 86 roc have computer
thanks for the response.
ive had this problem for years and i cant figure it out. i have new plugs, wires, cap, button, distributor, heads, intake, hell the engine only has 6 thousand on it. ive changed the carb, cam and lifters. i'm really out of ideas. i'll start checking around for a oscilloscope.
i even changed out the module in the distributor yesterday thinking it could be going bad! WRONG!!!
ive had this problem for years and i cant figure it out. i have new plugs, wires, cap, button, distributor, heads, intake, hell the engine only has 6 thousand on it. ive changed the carb, cam and lifters. i'm really out of ideas. i'll start checking around for a oscilloscope.
i even changed out the module in the distributor yesterday thinking it could be going bad! WRONG!!!
Supreme Member
Joined: Jan 2009
Posts: 2,313
Likes: 115
From: belle fourche,s.d.
Car: '82 z28
Engine: L83 5.7
Transmission: 700r4-1985
Axle/Gears: 3.42 posi
Re: help please, does 86 roc have computer
weak valve springs can cause that problem-my '69
camaro did that exact thing,right at 5000 rpm-springs
had 140,000 mi on them.
camaro did that exact thing,right at 5000 rpm-springs
had 140,000 mi on them.
Thread Starter
Member
Joined: Mar 2008
Posts: 251
Likes: 1
From: South Carolina
Car: 1986 Iroc-Z
Engine: 355 Phase 2 Bowtie heads
Transmission: 700r4
Axle/Gears: 342
Re: help please, does 86 roc have computer
yeah i thought about the springs too. i have had two different sets of heads, both fresh, same results. the second set of heads, i had the springs installed to match my cam. that doesnt mean the guy at the machine installed the stiffer springs i paid for though.
i've also tried a different coil.
let's say for shiz and giggles that my car has a rev limiter. if i ran a straight 12 volts to my coil, for test only, would that bypass my limiter?
i've also tried a different coil.
let's say for shiz and giggles that my car has a rev limiter. if i ran a straight 12 volts to my coil, for test only, would that bypass my limiter?
Supreme Member
Joined: Jan 2009
Posts: 2,313
Likes: 115
From: belle fourche,s.d.
Car: '82 z28
Engine: L83 5.7
Transmission: 700r4-1985
Axle/Gears: 3.42 posi
Re: help please, does 86 roc have computer
What about fuel delivery?-stock fuel pump would not
keep up at high rpm on my'82,car did not pop though,
would just start to buck and surge-fixed the problem
with an electric fuel pump that i had on hand.
The popping sounds like an ignition problem,but you
have subbed out all ignition parts with no improvement!
could try running12 v straight to the coil just to make
sure it is getting full voltage.There is no rev limiter on
thirdgen ignitions,ECM only controls the spark advance.
good luck!
keep up at high rpm on my'82,car did not pop though,
would just start to buck and surge-fixed the problem
with an electric fuel pump that i had on hand.
The popping sounds like an ignition problem,but you
have subbed out all ignition parts with no improvement!
could try running12 v straight to the coil just to make
sure it is getting full voltage.There is no rev limiter on
thirdgen ignitions,ECM only controls the spark advance.
good luck!
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