96 SL-1 stumbles for a few minutes

On Sat, 29 Jul 2006 01:32:38 GMT, Buster > wrote:

>Would a bad fuel pump only act up for a few minutes in the morning?
>Problem doesn't recur until next day. Car has new ECT, plugs, wires
>and fuel filter. Will try cleaning the throttle body.

Back to the bad fuel pump issue. If I just drove the car, and then
parked it. My starting habits 'covered' the fact the pump was bad. I
would turn the car on (without cranking), buckle up, and then start
the car. The moment pause in going ON to Cranking gave time for the
fuel pump to refill the system.

Now over night, the system would drain so much, that a moment was too
short, so the engine cranked hard, and ran like crap for the first few
minutes. Since I had my pump replaced the 97SL2 runs very well.

Ofcourse I still get those mysterious "Check Engine" lights. They
solid, never seen flashing, but when I got to an auto zone to have
them checked, the light goes out.

later,

tom @ www.WorkAtHomePlans.com






>Buster
>On Fri, 28 Jul 2006 13:36:30 -0400, Tom The Great >
>wrote:
>
>>On Fri, 28 Jul 2006 01:45:15 GMT, Buster > wrote:
>>
>>>Hi,
>>>I have a 1996 SL-1 manual with 120,000 miles on it. For about the
>>>first 5 minutes most mornings, it stumbles under medium load. Idles
>>>ok. If revved above 3500, it runs ok. But, when cruising down the road
>>>at 2000-2500 rpm, it will start to buck like crazy. I just downshift
>>>and drive at a higher rpm for a while. After about 5 minutes, it goes
>>>away. I have recently replaced the plugs, plug wires, fuel filter and
>>>engine coolant temp sensor. It rarely throws a code (unless I let it
>>>buck a lot) and if it does, the code tells me I have a cylinder
>>>misfire (not always the same cylinder). It doesn't seem to do it as
>>>much if it the ambient temp is above 80F. I only have a code reader,
>>>not a real scan tool, so I can't check sensors, etc. Any ideas?
>>>Thanks,
>>>Buster
>>
>>My 97SL2 had problems.....
>>
>>This the process that seemed to reduce and later elminate the
>>stalling, rough idling, and spurtering.
>>
>>1. I cleaned the throttle body.
>>2. Changed the Coolant Temperature Sensor.
>>3. Changed plugs and wires.
>>4. many bottles of Fuel injector cleaners.
>>5. Later, had the fuel pump replaced(Saturn finally found out it was
>>defective).
>>
>>1-4 I did myself, #5 was costly. So far this is the first summer
>>without stalls, rough starts, and sputtering.
>>
>>So from what you said, and what I did, it sounds like you should have
>>your fuel pump checked. You might have a problem with it.
>>
>>Sorry.
>>
>>later,
>>
>>tom @ www.Consolidated-Loans.info

Does it seem to be running lean when cold? The Coolant Temperature Sensor
is supposed to tell the engine computer to provide more fuel till the engine
warms up. If the CTS is defective and registering a "hot" engine even when
cold, then you might have drivability issues. I know you already said you
replaced it, but maybe that one was bad? Saturn CTS is known to fail often,
is cheap and easy to fix.

Bob

"Buster" > wrote in message
...
> Would a bad fuel pump only act up for a few minutes in the morning?
> Problem doesn't recur until next day. Car has new ECT, plugs, wires
> and fuel filter. Will try cleaning the throttle body.
> Buster
> On Fri, 28 Jul 2006 13:36:30 -0400, Tom The Great >
> wrote:
>
>>On Fri, 28 Jul 2006 01:45:15 GMT, Buster > wrote:
>>
>>>Hi,
>>>I have a 1996 SL-1 manual with 120,000 miles on it. For about the
>>>first 5 minutes most mornings, it stumbles under medium load. Idles
>>>ok. If revved above 3500, it runs ok. But, when cruising down the road
>>>at 2000-2500 rpm, it will start to buck like crazy. I just downshift
>>>and drive at a higher rpm for a while. After about 5 minutes, it goes
>>>away. I have recently replaced the plugs, plug wires, fuel filter and
>>>engine coolant temp sensor. It rarely throws a code (unless I let it
>>>buck a lot) and if it does, the code tells me I have a cylinder
>>>misfire (not always the same cylinder). It doesn't seem to do it as
>>>much if it the ambient temp is above 80F. I only have a code reader,
>>>not a real scan tool, so I can't check sensors, etc. Any ideas?
>>>Thanks,
>>>Buster
>>
>>My 97SL2 had problems.....
>>
>>This the process that seemed to reduce and later elminate the
>>stalling, rough idling, and spurtering.
>>
>>1. I cleaned the throttle body.
>>2. Changed the Coolant Temperature Sensor.
>>3. Changed plugs and wires.
>>4. many bottles of Fuel injector cleaners.
>>5. Later, had the fuel pump replaced(Saturn finally found out it was
>>defective).
>>
>>1-4 I did myself, #5 was costly. So far this is the first summer
>>without stalls, rough starts, and sputtering.
>>
>>So from what you said, and what I did, it sounds like you should have
>>your fuel pump checked. You might have a problem with it.
>>
>>Sorry.
>>
>>later,
>>
>>tom @ www.Consolidated-Loans.info

Any tips on how to tell if it's running lean? I'm pretty sure it runs
rich once it's warmed up, I get a lot of popping back in the exhaust
system when decelerating. Also, when I changed the ECT there was no
difference in performance or gauge operation.
Buster
On Sun, 30 Jul 2006 02:00:03 GMT, "Bob Shuman"
> wrote:

>Does it seem to be running lean when cold? The Coolant Temperature Sensor
>is supposed to tell the engine computer to provide more fuel till the engine
>warms up. If the CTS is defective and registering a "hot" engine even when
>cold, then you might have drivability issues. I know you already said you
>replaced it, but maybe that one was bad? Saturn CTS is known to fail often,
>is cheap and easy to fix.
>
> Bob
>
>"Buster" > wrote in message
.. .
>> Would a bad fuel pump only act up for a few minutes in the morning?
>> Problem doesn't recur until next day. Car has new ECT, plugs, wires
>> and fuel filter. Will try cleaning the throttle body.
>> Buster
>> On Fri, 28 Jul 2006 13:36:30 -0400, Tom The Great >
>> wrote:
>>
>>>On Fri, 28 Jul 2006 01:45:15 GMT, Buster > wrote:
>>>
>>>>Hi,
>>>>I have a 1996 SL-1 manual with 120,000 miles on it. For about the
>>>>first 5 minutes most mornings, it stumbles under medium load. Idles
>>>>ok. If revved above 3500, it runs ok. But, when cruising down the road
>>>>at 2000-2500 rpm, it will start to buck like crazy. I just downshift
>>>>and drive at a higher rpm for a while. After about 5 minutes, it goes
>>>>away. I have recently replaced the plugs, plug wires, fuel filter and
>>>>engine coolant temp sensor. It rarely throws a code (unless I let it
>>>>buck a lot) and if it does, the code tells me I have a cylinder
>>>>misfire (not always the same cylinder). It doesn't seem to do it as
>>>>much if it the ambient temp is above 80F. I only have a code reader,
>>>>not a real scan tool, so I can't check sensors, etc. Any ideas?
>>>>Thanks,
>>>>Buster
>>>
>>>My 97SL2 had problems.....
>>>
>>>This the process that seemed to reduce and later elminate the
>>>stalling, rough idling, and spurtering.
>>>
>>>1. I cleaned the throttle body.
>>>2. Changed the Coolant Temperature Sensor.
>>>3. Changed plugs and wires.
>>>4. many bottles of Fuel injector cleaners.
>>>5. Later, had the fuel pump replaced(Saturn finally found out it was
>>>defective).
>>>
>>>1-4 I did myself, #5 was costly. So far this is the first summer
>>>without stalls, rough starts, and sputtering.
>>>
>>>So from what you said, and what I did, it sounds like you should have
>>>your fuel pump checked. You might have a problem with it.
>>>
>>>Sorry.
>>>
>>>later,
>>>
>>>tom @ www.Consolidated-Loans.info
>

I'm pretty sure it typically fails the "other way" - it goes out with
too high a resistance value. Consistantly, it 'indicates' a low
temperature condition when that is not the case.
It thinks the engine is too cold, and tries to warm it up even when its
hot.
I know that you can increase EGT by leaning out the mixture, but I dont
think that is how it manages to "warm up" the engine. With an over
rich mixture (and higher RPMs especially), I think you might be making
the engine run warmer, even if EGT is not high.

-WaV

Bob Shuman wrote:
> Does it seem to be running lean when cold? The Coolant Temperature Sensor
> is supposed to tell the engine computer to provide more fuel till the engine
> warms up. If the CTS is defective and registering a "hot" engine even when
> cold, then you might have drivability issues. I know you already said you
> replaced it, but maybe that one was bad? Saturn CTS is known to fail often,
> is cheap and easy to fix.
>
> Bob
>

Tom, I tried your technique and it didn't help. I usually just turn
the car on. Today, I turned it to the RUN position, then took the
trash to the curb. After about a minute, I started the car and it ran
the same.
Buster
On Sat, 29 Jul 2006 11:07:32 -0400, Tom The Great >
wrote:

>On Sat, 29 Jul 2006 01:32:38 GMT, Buster > wrote:
>
>>Would a bad fuel pump only act up for a few minutes in the morning?
>>Problem doesn't recur until next day. Car has new ECT, plugs, wires
>>and fuel filter. Will try cleaning the throttle body.
>
>Back to the bad fuel pump issue. If I just drove the car, and then
>parked it. My starting habits 'covered' the fact the pump was bad. I
>would turn the car on (without cranking), buckle up, and then start
>the car. The moment pause in going ON to Cranking gave time for the
>fuel pump to refill the system.
>
>Now over night, the system would drain so much, that a moment was too
>short, so the engine cranked hard, and ran like crap for the first few
>minutes. Since I had my pump replaced the 97SL2 runs very well.
>
>Ofcourse I still get those mysterious "Check Engine" lights. They
>solid, never seen flashing, but when I got to an auto zone to have
>them checked, the light goes out.
>
>later,
>
>tom @ www.WorkAtHomePlans.com
>
>
>
>
>
>
>>Buster
>>On Fri, 28 Jul 2006 13:36:30 -0400, Tom The Great >
>>wrote:
>>
>>>On Fri, 28 Jul 2006 01:45:15 GMT, Buster > wrote:
>>>
>>>>Hi,
>>>>I have a 1996 SL-1 manual with 120,000 miles on it. For about the
>>>>first 5 minutes most mornings, it stumbles under medium load. Idles
>>>>ok. If revved above 3500, it runs ok. But, when cruising down the road
>>>>at 2000-2500 rpm, it will start to buck like crazy. I just downshift
>>>>and drive at a higher rpm for a while. After about 5 minutes, it goes
>>>>away. I have recently replaced the plugs, plug wires, fuel filter and
>>>>engine coolant temp sensor. It rarely throws a code (unless I let it
>>>>buck a lot) and if it does, the code tells me I have a cylinder
>>>>misfire (not always the same cylinder). It doesn't seem to do it as
>>>>much if it the ambient temp is above 80F. I only have a code reader,
>>>>not a real scan tool, so I can't check sensors, etc. Any ideas?
>>>>Thanks,
>>>>Buster
>>>
>>>My 97SL2 had problems.....
>>>
>>>This the process that seemed to reduce and later elminate the
>>>stalling, rough idling, and spurtering.
>>>
>>>1. I cleaned the throttle body.
>>>2. Changed the Coolant Temperature Sensor.
>>>3. Changed plugs and wires.
>>>4. many bottles of Fuel injector cleaners.
>>>5. Later, had the fuel pump replaced(Saturn finally found out it was
>>>defective).
>>>
>>>1-4 I did myself, #5 was costly. So far this is the first summer
>>>without stalls, rough starts, and sputtering.
>>>
>>>So from what you said, and what I did, it sounds like you should have
>>>your fuel pump checked. You might have a problem with it.
>>>
>>>Sorry.
>>>
>>>later,
>>>
>>>tom @ www.Consolidated-Loans.info

On Wed, 02 Aug 2006 23:40:54 GMT, Buster > wrote:

>Tom, I tried your technique and it didn't help. I usually just turn
>the car on. Today, I turned it to the RUN position, then took the
>trash to the curb. After about a minute, I started the car and it ran
>the same.
>Buster

Sorry to hear that. I was just explaining what happened to me, it
wasn't meant as a fix. You need to get your car to a qualified
mechanic.

tom


>On Sat, 29 Jul 2006 11:07:32 -0400, Tom The Great >
>wrote:
>
>>On Sat, 29 Jul 2006 01:32:38 GMT, Buster > wrote:
>>
>>>Would a bad fuel pump only act up for a few minutes in the morning?
>>>Problem doesn't recur until next day. Car has new ECT, plugs, wires
>>>and fuel filter. Will try cleaning the throttle body.
>>
>>Back to the bad fuel pump issue. If I just drove the car, and then
>>parked it. My starting habits 'covered' the fact the pump was bad. I
>>would turn the car on (without cranking), buckle up, and then start
>>the car. The moment pause in going ON to Cranking gave time for the
>>fuel pump to refill the system.
>>
>>Now over night, the system would drain so much, that a moment was too
>>short, so the engine cranked hard, and ran like crap for the first few
>>minutes. Since I had my pump replaced the 97SL2 runs very well.
>>
>>Ofcourse I still get those mysterious "Check Engine" lights. They
>>solid, never seen flashing, but when I got to an auto zone to have
>>them checked, the light goes out.
>>
>>later,
>>
>>tom @ www.WorkAtHomePlans.com
>>
>>
>>
>>
>>
>>
>>>Buster
>>>On Fri, 28 Jul 2006 13:36:30 -0400, Tom The Great >
>>>wrote:
>>>
>>>>On Fri, 28 Jul 2006 01:45:15 GMT, Buster > wrote:
>>>>
>>>>>Hi,
>>>>>I have a 1996 SL-1 manual with 120,000 miles on it. For about the
>>>>>first 5 minutes most mornings, it stumbles under medium load. Idles
>>>>>ok. If revved above 3500, it runs ok. But, when cruising down the road
>>>>>at 2000-2500 rpm, it will start to buck like crazy. I just downshift
>>>>>and drive at a higher rpm for a while. After about 5 minutes, it goes
>>>>>away. I have recently replaced the plugs, plug wires, fuel filter and
>>>>>engine coolant temp sensor. It rarely throws a code (unless I let it
>>>>>buck a lot) and if it does, the code tells me I have a cylinder
>>>>>misfire (not always the same cylinder). It doesn't seem to do it as
>>>>>much if it the ambient temp is above 80F. I only have a code reader,
>>>>>not a real scan tool, so I can't check sensors, etc. Any ideas?
>>>>>Thanks,
>>>>>Buster
>>>>
>>>>My 97SL2 had problems.....
>>>>
>>>>This the process that seemed to reduce and later elminate the
>>>>stalling, rough idling, and spurtering.
>>>>
>>>>1. I cleaned the throttle body.
>>>>2. Changed the Coolant Temperature Sensor.
>>>>3. Changed plugs and wires.
>>>>4. many bottles of Fuel injector cleaners.
>>>>5. Later, had the fuel pump replaced(Saturn finally found out it was
>>>>defective).
>>>>
>>>>1-4 I did myself, #5 was costly. So far this is the first summer
>>>>without stalls, rough starts, and sputtering.
>>>>
>>>>So from what you said, and what I did, it sounds like you should have
>>>>your fuel pump checked. You might have a problem with it.
>>>>
>>>>Sorry.
>>>>
>>>>later,
>>>>
>>>>tom @ www.Consolidated-Loans.info