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Discussion Starter · #1 ·
I have a 2001 Impala LS and I was on the highway with it yesterday doing about 75mph. I went to pass a car, so I tried to speed up. When I hit the gas, it sounded like the engine was just about revved out, but the tach read only 3000 rpm. It wouldn't go above 3000 whether I let off the gas or hit it harder, then the engine started "stalling"(it felt like the fuel was cutting off and it was losing power, then it would kick back in, then out, etc). I got back into my lane and slowed down, but then the check engine light started flashing(no messages ever came across the message center). It did this until I got back down to 65 mph or so, and now it seems to do it every time I'm going over about 45 mph and try to speed up somewhat quickly(like to pass someone). The day I got the car, I had the spark plugs and wires changed and also got a new fuel pump put in. Could either of these be the problem? If not, any suggestions? Thanks in advance for any help you can offer.
 

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Discussion Starter · #2 ·
I just wanted to add FWIW, about 5-10 minutes after this incident on the highway, I stopped at a gas station and got gas in it. When I went to restart it, it wouldn't and it flashed "Security". I called my grandpa(who I got the car from) and he said it was the Passlock and talked me through the restart process. I think that all makes sense to me now, but I'm wondering if Passlock doing that to me had anything to do with the crazy actions on the highway(or vice versa).
 

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Discussion Starter · #3 ·
I just wanted to refresh this thread, hopefully someone can help me. The problem is continuing. It seems that when I'm above about 45mph and hit the gas(to pass someone, or just speed up), it bogs down and the rpms jump up and down like the car's trying to choke out completely. If I ease on the gas(gaining maybe 1 mph every minute or so), the rpms don't jump, but the motor still seems to bog down. I can't even begin to understand what the problem may be. It acts normal at low speeds, and even takes off perfect from a stop sign. The check engine light isn't on(the other day it flashed, but went out before I even parked it) nor are there any messages on the message center.
 

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I don't really know anything about these cars, but since nobody has chimed in on this yet,... I would take it to professional diagnostic mechanic, bcuz your obviously experiencing some kind of air/fuel (lean/rich) computer hick-up. Expect to pay between 60-90 buck an hour to hook a computer to your car.
So, if you know someone that has access to one these, you might wanna give them a call, it'll save you alot of money.
Hopefully, someone on here has experiened a similar situation and has a better remedy for this sort of thing.
 

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stalling and passlock

I have a 2001 3.8L Impala.

I had a similar problem (bogging down, high rpms, no speed).
At first it occured only at high speeds but eventually I wasn't able to go faster than 40 or 50mph.
It turned out to be my catalytic converter...it was clogged and needed to be replaced. I got an aftermarket CC installed for around 300.

As for the passlock, I have that problem too. When it screws up, the fuel injectors are disabled for 15mins. After that, I turn the key a few times (sometimes I have to pop it into neutral) and it starts.

I bought the car used and recently discovered an remote starter mounted underneath the steering wheel. Apparently, to mount an remote starter you have to bypass the passlock system. It seems like someone screwed up because PASSLOCK would give me problems. Sometimes, it would happen twice in a day, other times once every few months. I ended up unplugging the remote starter and I've only had the passlock problem once since then (it's been about 2 months). I should also mention that whoever installed the autostarter installed a switch under the steering column. From what I read, this switch should toggle the passlock system (either on or off). I toggled the switch from the last time the passlock problem happened and so far the problem hasn't reoccured...I wonder if it will last.

In any case, ask your grandpa if he installed a remote starter.
Also, you mentioned your grandpa told you how to reset the passlock problem...do you mind sharing that info??

Thanks,
Bart
 

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Take your car to a local auto parts store such as Auto Zone or O'Reilly's and use or have them use the OBD-II code scanner on your car. It will probably tell you that the "cat efficiency is below threshold". If so have the catilictic converter changed. Other wise what ever threw the light should still be in the computer.
 

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Discussion Starter · #7 ·
Thanks for the replies. I'm not too excited about replacing the cat, though. The check engine light isn't on anymore, so could AutoZone diagnose it still?

As for how to reset it, all I did was turn the key in the on position for about 5 minutes, tried to start it(he didn't tell me to do that, I just got anxious:biggrin:), then got out and locked the car with the keyless thing, then unlocked just the driver door(pressed it once), got in and it started. Maybe I just got lucky, but it worked, and that's how he told me he did it.
 

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The check engine light isn't on anymore, so could AutoZone diagnose it still?
Yes even though the light has turned off the error code exspecially if the cat efficiency is low will still be in the PCM. The PCM may wait awhile before tripping the MIL (malfuction indicator lamp, aka "Check Engine" lamp back on.
 

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Discussion Starter · #9 ·
Just got back from AutoZone and to their surprise(since the light wasn't on), it tripped a code. The guy at the store said he didn't know what it meant was wrong and he said there's no part recommendation for it either. This is what it says:
Definition
MAP(Man. Absolute Pressure)/BARO or MAF(Mass Air Flow)/VAF(Vane Air Flow) sensor condition
Explanation
All vehicles have one or more of these components. Engine load or the air volume entering the engine is measured by these components. The computer has recognized a return signal error.
Probable Causes
1.-Vacuum hose off, cracked or passage blocked-Engine mechanical timing condition.
2.-Throttle body intake tube loose, off or cracked.
3.-BARO(Barometer)/MAP(Manifold Absolute Pressure) defective.
4.-VAF(Vane Air Flow) MAF(Mass Air Flow) sensor dirty or defective.

All the hoses seem to be intact, so what does all this mean?:confused:
 

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If he did not reset the PCM I would go and try a differnt person at AZ and see if they can pull up the correct information. The engine will use one to up to three of those items, I am not sure which ones yours has. But if you did get the code writen down you might call the local dealer and aske them what the code means.

You might even try to unhook the battery for an hour and then reconnect it and see if the system is reset and runs properly. If it is a one time error it may not trip out the PCM again or not for a while. If there was a problem then usually with in 100 to 200 miles the same code will retrip the CE lamp.

If after reconnecting the battery the engine still has the same problem then it will need to be further checked by a mechanic to find the fault in the sensors.
 
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