No power under 2,000 RPM then pulls like a Mother???
#1
No power under 2,000 RPM then pulls like a Mother???
Hey everybody,
I am having a problem with my 86 TA 305TPI/700R4. When I pull out my car seems to have NO power whatsover under 2K RPM's in 1st, its barely rolling, but once it shifts to 2nd the car gets back its normal power. I'm suspecting bad timing, I just ordered a timing light and will fix that soon, could this be casuing my problem?
Any other suggestions? IAC, O2, TPS???
-Max
I am having a problem with my 86 TA 305TPI/700R4. When I pull out my car seems to have NO power whatsover under 2K RPM's in 1st, its barely rolling, but once it shifts to 2nd the car gets back its normal power. I'm suspecting bad timing, I just ordered a timing light and will fix that soon, could this be casuing my problem?
Any other suggestions? IAC, O2, TPS???
-Max
#3
Could be timing... Are you throwing any codes? Check the EST bypass wire.. the tan with a black stripe wire running by the passenger side... if it's disconnected it'll be a the base timing and wouldn't be computer controlled.. It could be that, but I'm thinking it's probably something else.
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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else
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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else
#4
Thnaks for the help, but again I doubt that its timing. I'm leaning towards the Oxygen sensor failure. IF it fails I'm thinking it would casue the engine to stay in "open loop" (poor idle, rich mixture just to warm the engine up) and never to switch to "closed loop". Do the symptonms sound like that could be the cause?
If so how much is it for a replacement O2 sensor and wheres the best place to buy?
Thnaks for the help,
-Max
If so how much is it for a replacement O2 sensor and wheres the best place to buy?
Thnaks for the help,
-Max
#5
Hey,
Bosch makes O2's that go for about $30 at autzone, peps, etc.. One from the dealer is like $80.
I'm kinda torn though.
I've had problems with bosch O2 sensors in the past, I've had one go bad about a week after I installed it, and when it was replaced with a new bosch, the car ran really weak. I relaced it with a gm O2, and it ran alot better.
I'm looking for input as to if anyone has had these probs with aftermarket O2. ?
Bosch makes O2's that go for about $30 at autzone, peps, etc.. One from the dealer is like $80.
I'm kinda torn though.
I've had problems with bosch O2 sensors in the past, I've had one go bad about a week after I installed it, and when it was replaced with a new bosch, the car ran really weak. I relaced it with a gm O2, and it ran alot better.
I'm looking for input as to if anyone has had these probs with aftermarket O2. ?
#6
Well, the best place to buy an O2 sensor is the parts store (Advance Auto, Autozone, etc.). It screw into the driver's side exhaust manifold.
I'm not certain, but I don't think the O2 sensor controls whether or not the computer is in open or closed loop mode. I think that's dependant on the engine temperature and throttle position. Could be mistaken.
Oh and umm... I think an o2 sensor is about 10-20 bucks? I can't remember. It would be beneficial to change it if it's never been done, even if it doesn't clear up the problem.
I'm not certain, but I don't think the O2 sensor controls whether or not the computer is in open or closed loop mode. I think that's dependant on the engine temperature and throttle position. Could be mistaken.
Oh and umm... I think an o2 sensor is about 10-20 bucks? I can't remember. It would be beneficial to change it if it's never been done, even if it doesn't clear up the problem.
#7
I doubt the 02 sensor is causing the low power under 2000RPM or any other problems. The ECM gets imput from the 02 sensor at Wide Open Throttle but ignores what it reads. At WOT the ECM reads preprogramed tables to achieve the WOT 13:1 air/fuel ratio. The 02 sensor is read only when the ECM is trying to maintain an air/fuel ratio of 14.7:1 (part throttle)
If the Torque Converter locks up you know that it is in closed loop if not -open. Get a new 02 sensor either way.
[This message has been edited by whiteroc (edited September 28, 2001).]
If the Torque Converter locks up you know that it is in closed loop if not -open. Get a new 02 sensor either way.
[This message has been edited by whiteroc (edited September 28, 2001).]
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#8
Anybody else?
This week I'm getting a new TB with vith nice and clean passages, I'm hoping this will clear things up. A new IAC and TPS will be included too. My previous TB has a bad IAC and a broken minimum air adjustment screw.
This week I'm getting a new TB with vith nice and clean passages, I'm hoping this will clear things up. A new IAC and TPS will be included too. My previous TB has a bad IAC and a broken minimum air adjustment screw.
#9
Mine was pretty lame when the O2 sensor wire burned on the exhaust manifold (not the pigtail), and after a couple O2 sensors and fixing the wire it still wouldn't run. I then determined that the O2 sensor circuitry in the ECM was fried and replaced the ECM. Made a big difference.
So I think it's either your O2 sensor, a bad spot in the TPS, or fuel injector/pressure issues. Just my $0.02.
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1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."
So I think it's either your O2 sensor, a bad spot in the TPS, or fuel injector/pressure issues. Just my $0.02.
------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."
#10
It really seems to me like its running in continuous open loop. It has a bad idle, very rich mixture, and no power. So before I go swapping ECM's or cleaning injectors would a faulty O2 sensor or CTS casue this?
-Max
-Max
#11
Oh Christ, it got REAL bad today when I went to start the car. I started it up and besides my exhaust stinking of gas it stortaed popping backfiring and what not. In adition to that I had a horrible idle and popping noises coming from the intake as well. Terrible hesitation when I step on the gas and car barely stayed alive. I warmed up th car to 220* and still all the synptoms remained.
I think only one thing could cause all of these problems: a faulty ECM. So if somebody has a good one out of an 86-89 TPI (305 and 350's) for a reasonable price please E-mail me.
Also if I'm jumping to conclusions, fell free to correct me.
-Max
I think only one thing could cause all of these problems: a faulty ECM. So if somebody has a good one out of an 86-89 TPI (305 and 350's) for a reasonable price please E-mail me.
Also if I'm jumping to conclusions, fell free to correct me.
-Max
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