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Car Surge and Chugging Questions
Question: 2001 Toyota 4Runner, mileage: 80,000 For the past two weeks since
having my car serviced (grease and oil change) I have noticed a surging/losing power
problem. Initially the problem was when I was just beginning to accelerate from
stop, then the pattern changed to running ok when I first drove the car say 5km
to the supermarket and then when I came to drive home it would surge/lose power/buck
after a period of the car stopped for 20 minutes. After noticing this pattern, I
repeated it and the fault happened again. The car is an automatic and I have had
an automatic transmission service, had the coil replaced and the air intake temp
sensor as this was the only code the testing equipment showed. After the new air
intake temp sensor, the pattern changed again to playing up intermittently and today
the mechanic experienced the problem driving with the testing equipment attached
and it showed no codes. I normally drive it in overdrive and economy and the mechanic
thought it might be cycling in and out of overdrive but it still plays up with the
overdrive off. The mechanics are stumped and are contemplating a problem in the
onboard computer. I have noticed it is using more petrol than before. Up until this
problem, I have never had anything go wrong with the car and it has not lost a drop
of oil or water in the six years I have had it. It has had all its book services.
Prior to the service, the car somehow picked up a bit of plastic on the road and
it is melted to the outside of the exhaust. This is why I took it for a service
in the first place. Now I am wishing I never took it to the garage at all, as the
car ran fine before it and played up after but the garage assumes no responsibility
for causing it and says it is just coincidence. I have also had the catalytic converter
checked and that is clear. Do you have any other ideas as to the cause of the problem?
I have already spent over $1200 testing mechanics theories and don't want to spend
anymore dead money. I would appreciate any help you can give me.
Answer: This is difficult because the computer can't detect
a problem, your vehicle thinks everything is ok. In reality what is happening is
the electrical component inside the MAF sensor becomes contaminated by the impurities
in the air. These containments imbed themselves to electrical component that senses
the air flow causing the sensor to be slightly off, but not enough to trigger the
MIL (malfunction indicator lamp). Replace the MAF sensor with a new sensor and you're
problem will go away, plus your car get better mileage and performance. (Mass Air
Flow MAF sensor or Air Intake Sensor AIS, depending on manufacture. It does the
same thing with different names).
Question: 1997 Chevrolet S10 Blazer, mileage: 178,000. I'm having a "surging"
problem on my S10 blazer with I've already replaced the TPS, Oxygen sensor, and
installed a transmission oil cooler to help fix another problem it's having with
staying in overdrive and constantly wants to downshift. The problem also seems to
get worse as the fuel level goes down. The gas mileage is a little better, but I'm
still getting this "surging" which is also aggravating the transmission problem.
Anyhow, I'm now in the process of replacing the in-tank fuel pump. Before I completely
re-installed the tank, I thought I would try to run the pump in a pan of gas to
make sure everything was working. It worked okay. To make sure though that the "real
world" output was okay, I then installed the pump in the tank with a few gallons
of fuel in it. I then ran the pump again with the tank level lying on the ground,
but the pump's output now "surged" again to the same frequency I've been experiencing
when driving the truck k. It sounds like the pump stalls out and then "loads down"
as the screen picks up fuel again for a few seconds and then stalls out again. When
driving, it does this surging especially the lower the fuel gets. I've got a feeling
now that this fuel pump replacement isn't going to fix this problem. I checked to
ensure that the pumps pickup is reaching all the way to the bottom of the tank (it's
okay). The only thing I can think of is that there was either a recall of the fuel-tanks/fuel
pump systems which was never done on this truck or the fuel tank/fuel pump in my
truck are incompatible or wrong or something.
Answer: When we replace fuel pumps on S10 Blazers, we remove
the vibration dampener that is located directly above the fuel pump and replace
it with a longer hose.
Question: 1998 Dodge Ram 1500 mileage: 104,000. Truck would
buck and surge at various speeds. Stalls every time you come to a stop at a light.
Took it to the shop, they put it on their computer - no readings of anything wrong.
The mechanic then drove the car, came back and said it seems to be shutting off
for a second and coming back on. His diagnosis was an ignition problem. Changed
the ignition module and coil pack. We did this a month ago. Car would still buck
and surge but stopped stalling. Car would drive fine sometimes and other times it
would buck and surge. They seem to think it's electrical but don't know where
to go to start looking. They did talk to a tech that told them there is a secondary
wire going to the computer that sometimes shorts out. Well they cut open the wire
harness going to the computer under the car and found no bad wires. So if you guys
have any ideas? This car now drives, bucks and surges with the dashboard going nuts
every time you drive it; step on the pedal.
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then suspect the fuel pump.
Question: 1999 Pontiac Bonneville, mileage: 60,000. My Pontiac Bonneville
SE surges between 1700 and 2500 Rpms only when the car is completely warmed up and
going between speeds of 30-35 then 55-60 or anytime uphill at those low Rpms. The
car seems to loose power then immediately afterwards will surge back to the RPM
it should be. The dealer has replaced the fuel filter, plugs, coils, wires, and
air filter, serviced the fuel injectors and replaced the torque converter. They
said they now want to replace the transmission to see if that fixes the problem.
My guess is the engine is next. No error codes are displayed in their diagnostics.
So, they are "experimenting" until they find it or I run out of money. I have already
spent over $2,000 for these "services". I noticed someone else with a similar question
to you with same car and you suggested EGR valve. Any ideas?
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then what is happening is the electrical component inside
the MAF sensor becomes contaminated by the impurities in the air. These containments
imbed themselves to electrical component that senses the air flow causing the sensor
to be slightly off, but not enough to trigger the MIL (malfunction indicator lamp).
Replace the MAF sensor with a new sensor and you're problem will go away, plus your
car get better mileage and performance. (Mass Air Flow MAF sensor or Air Intake
Sensor AIS, depending on manufacture. It does the same thing with different names).
Question: 2001 Chevrolet Corvette, mileage: 84,000. My Vette seems to
idle fine and cruises fine but when I let off the accelerator from 55 mph, I can
feel the car surging. The rpms seem to fluctuate up and down 2-4 hundred rpms until
it gets down to a normal idle. I am thinking of replacing the IAC (idle air control).
Answer: Scan the computer for codes. It is possible you have
a weak oxygen sensor.
Question: 1994 Nissan Sentra, mileage: 135,000. Car surges and stutters
if speed is between 50 mph to 60 mph when feathering the accelerator. Example: Coming
down off the Chesapeake Bay Bridge in Md. when not accelerating but not decelerating
between 50 mph to 60 mph the car starts surging/stuttering. Have replaced all ignition
parts/fuel filter. Car runs smooth otherwise. Thanks
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then the EGR valve may be cycling opening and closing. Replacing
the valve may cure the surging. It is also possible, if your car is equipped with
air conditioning, that the air conditioning compressor may be cycling on and off,
lugging the motor.
Question: 2001 Ford Escort Wagon, mileage: 59,000. Hello, I Just bought
this car with 58,000 on the odometer, it starts, runs, idles and accelerates perfectly,
the only problem I have is the engine seems to surge at around 40 mph. Tonight I
went on an extended highway drive having all of 1000 miles experience with the car,
and made a conscious effort to keep the car at speed and noticed a surge in the
engine/car speed, I steadied my foot on the accelerator as best I could and noticed
the car would go up a few miles per hour and settle back down to the set speed only
to surge again a few minutes later and settle down to the set speed again. I now
realize that the reason the car was slowing down was because I would automatically
adjust for the speed surge by releasing some pressure on the accelerator, of course
after 5 or 10 surges, and releasing a little pressure every time I felt the car
increase in speed I'd be down 15 or 20 Mph from my intended speed. As part of the
purchasing agreement I took the car to a Ford dealership and had it checked out,
the wrench replaced the mass air flow sensorr and also replaced a couple of plugs
and plug wires, and otherwise was given a clean bill of health. Any ideas? Thanks,
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then suspect the oxygen sensor.
Question: 1999 Dodge Caravan, mileage: 178,000. Only after highway
speeds, then when coming into traffic and creeping along at slow speeds I notice
as if the feeling of the vehicle pulling, then relax, pulling, then relax, while
all this time I keep the accelerator steady. It's like having out-of-round
wheels, only from front to back instead of up and down. Is there an explanation
for this?
Answer: It sounds like you have drive axles that need replacing
to repair problem.
Question: 2004 Nissan Altima, mileage: 50,000. The problem started
with the idle speed fluctuating from about 1000 to 2000 rpm when the vehicle was
sitting at an idle. This fluctuation was fairly rapid (about every 5-10 seconds).
Then after a couple of hundred miles, the idle speed stayed at 2000-2400 rpm.
Now when accelerating, the engine surges terribly and is getting bad fuel mileage.
When the surge occurs a small amount of black smoke puffs out of the exhaust pipe.
There is also some kind of relay under the hood, over the right fender beside the
battery making a rapid irregular clicking noise. Could this be related?
I think the problem is in the emission control system but I'm definitely in over
my head. Can you help? Thanks a lot!
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then suspect a failed fuel pressure regulator.
Question: 1998 Chevrolet Lumina mileage: 168,000. Please help. My
car has been to the local GM dealer 8 times. When traveling at highway speeds
55-65 mph. With the A/C on. Ambient temp at 60 Degrees or above and
going uphill. The car surges. You can see the tach go up from 2000 to
2200 rpm and back. As soon as your on level ground car runs fine. The
dealer has replaced Plugs, Wires, air filter, fuel filter and it hasn't changed.
Also, it shows no fault codes. Please tell me what you think it could be.
Thanks!
Answer: First scan the PCM for trouble codes using a hand
held engine scanner, Then repair codes by replacing failed sensor as needed.
If no codes are present then what is happening is the electrical component inside
the MAF sensor becomes contaminated by the impurities in the air. These containments
imbed themselves to electrical component that senses the air flow causing the sensor
to be slightly off, but not enough to trigger the MIL (malfunction indicator lamp).
Replace the MAF sensor with a new sensor and you're problem will go away, plus your
car get better mileage and performance. (Mass Air Flow MAF sensor or Air Intake
Sensor AIS, depending on manufacture. It does the same thing with different names).
Question: 1998 Chevrolet 1500 4x4 truck, mileage: 195,000. Replaced
engine has about 200 miles on it and computer was replaced recently. Engine
has started random surging (especially when cold outside), sometimes while being
driven and other times on startup. Truck has to be shut off and then won't
restart (starter and battery are fine). I didn't see any references to surging
in other fuel injector, pump or filter solutions. The dealer can't help, as
there are no computer codes showing. Any advise?
Answer: If no codes are present then what is happening is the electrical
component inside the MAF sensor becomes contaminated by the impurities in the air.
These containments imbed themselves to electrical component that senses the air
flow causing the sensor to be slightly off, but not enough to trigger the MIL (malfunction
indicator lamp). Replace the MAF sensor with a new sensor and you're problem will
go away, plus your car get better mileage and performance. (Mass Air Flow MAF sensor
or Air Intake Sensor AIS, depending on manufacture. It does the same thing with
different names).
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