Question: 2004 Ford
E-150 Club Wagon mileage: 78,000. Van has an
intermittent miss while accelerating. Van has had a
recent complete tune-up, complete with new oxygen
sensor. Has been to Ford garage 4 times and checked on
their analyzer with EGR problem. EGR valve and
positioning sensor has been replaced twice with no
results. Ford cannot seem to get it fixed. They say it
is internal carbon buildup and would have to go into the
top end of the engine to correct, very difficult in the
tight space on top of engine in a van. I have run
several cans of fuel system cleaner thru the gas but has
not helped. Ford said they disabled the EGR system and
the van ran fine. But, of course, they cannot leave it
disabled. Is there a way to dissolve or remove carbon
buildup without actually going into the inside of the
engine?
Answer: This is difficult because
the computer can't detect a problem, your van 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 (heavies) 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:
2004 Chevrolet Impala mileage: 84,000. Engine began to
miss shortly after I ran out of gas one day. Now,
engine misses mostly when cold while lightly
accelerating. Seems to miss only when the throttle
is slightly applied and held steady. When at
cruising speed, it will also miss at times. It
never misses at idle or when under medium to heavy
acceleration. Dealer couldn't find problem, but
did an ERG cleaning of the system. A fuel filter
has been replaced, sparkplugs and wires have been
replaced.
Answer:
Your car is ready for a tune up including spark plugs,
spark plug wires, fuel filter and air filter. Replace as
needed to repair problem.
Question:
2002 Chevrolet Corvette mileage: 75,000. What typically
causes a trouble code I've replaced the oxygen
sensor twice; the catalytic converter has been replaced.
Could you point me in the direction of what components
would be faulty since I have replaced many? Thanks in
advance.
Answer: It
sounds like your car is ready for a
Mass Air Flow sensor. Replace with new to repair
problem.
Question:
2001 Honda Accord mileage: 74,500. I just changed my
plugs and wires and I did it one by one (took off one
wire then the plug, put new plug back in then the new
wire) and I’m positive that it is in the right order and
I started it after I got done and it would idle and rev
up fine but when I took it out for a ride and got on the
gas it started miss-firing so I got out to make sure
that nothing was loose and everything was fine. It
baffled me so I ask a few other people and they didn’t
know, can you help?
Answer:
This can happen when inferior replacement parts have
been installed. OEM auto parts are the professional
choice just for problems like this.
Question: 2002 Dodge 1500 Ram Truck,
mileage 59,000: My truck has been bucking and jerking a
lot lately. It's a 5 speed. Bucks and jerks as you gain
rpms in each gear. It usually starts at around 1800-2200
rpms, but varies. I have had the service engine light
come on a few times...it goes out after a while. I took
it to the garage and they said it was a fuel pressure
regulator leaking and replaced it at $382...it is still
bucking and jerking. They then said it had plugged
injectors... cleaned twice and still jerking. They said
the codes said cylinders 1, 3, 6 were misfiring. They
said bad gas...dropped tank and cleaned but then they
said it wasn't the gas after all as the tank was clean.
They replaced the fuel pump after breaking the sending
unit on it and replaced the fuel filter. It is still
bucking and jerking...service engine light on again.
They said codes say cylinders 1,3,4,6 are misfiring
now....needs injectors in all 4 cylinders. Would this be
correct as it sometimes seems to run GREAT...other times
it bucks and jerks. I'm at a loss as the garage “seems”
to be guessing now and it is getting costly for a “no
fix” so far...$643 for the 4 injectors replaced if it
needs it as they say it does. Any suggestions?
Answer: It sound like you need a major
tune up
including
spark plugs,
spark plug wires,
fuel filter and
air filter. Replace as needed
to repair problem.
Question:
1997 Chevrolet Corvette
mileage 70,000. My Corvette just died at a stop light
recently; it was very hard to restart and ran very
poorly. After starting, it sounded like it was running
on 3 cylinders and died out again. Towed it home and
pulled a couple spark plugs which were ok. Tried to
start the car again and it ran fine for about 15 seconds
and then ran real rough and died again. Then I checked
for engine codes and it came up with no code. I replaced
both the power and burnoff relays along with the mass
air flow sensor because it was the original. Also
changed the spark plugs. Went to start the car and STILL
have the same problem, sounds like it's idling on 3
cylinders and dies out. I also noticed when the car was
idling very rough that the right side catalytic
converter looked red as if it was very hot. Any ideas
what's wrong?
Answer:
Try replacing the fuel pump. If the fuel pump
malfunctions it can cause the engine to run rough and
misfire. Replace fuel pump with new to recheck system.
Question:
2003 Mazda MPV Van
Mileage: 82,000. The car is running really rich,
especially when I start it in the morning. When the car
is warm, it seems to run fine, well most of the time.
Parts I have replaced recently are the O2 sensor, timing
belt, distributor cap, spark plug wires/plugs, and air
filter. I am currently getting about 12 miles to the
gallon.
Answer:
We suspect that the
fuel pressure regulator has failed and needs
replacing.
Question: 2002 Honda Accord, Mileage: 83,000.
Being adventurous and persistent, I decided to replace
my own timing belt...I just finished today. I was very
careful to line up all the marks, and I was ecstatic
when the car actually started after I put everything
back together. But I have a check engine light that is
on that doesn't remove itself with the simple negative
battery cable removal trick, and the car runs
great...until the motor speed gets to 3000 rpm where it
bounces in a range of 2750 to 3250 rpm, independent of
how much gas I apply. I have taken the valve cover
gasket off to check the marks on the cam to make sure
that they line up with the crank...and they both look
perfect. I'm pretty sure the balance shafts are correct
as well...I was very careful. Could I have damaged
something to cause this problem? Is the car so old that
"correct/factory timing" is off and I should adjust for
that? Please help if you can...btw, this car doesn't
have adjustable spark timing, as far as I know.
Answer: Look at the air intake senor to
make sure it is connected. This is the one item that
causes a check engine light on reassembly.
Question: 2000 Infinity G35
3.5 Coupe, miles: 45,980. Hey I really love your site.
This has stumped other mechanics. You're my only hope.
The car usually idles fine, but when you put it in gear
and step on the gas it sounds like it backfires in the
engine up by the air filters? This happens on Initial
acceleration but gets better like on the freeway. I took
it to a mechanic who changed the TPS again and said it
was fine now. Months later the same thing happened, it
came back. Went to another mechanic and did it all over
again. What could it be? Could it be the actual computer
that's fried? If I go to another mechanic, how do I know
they know what they are doing because they seem to know
about as much as I do with this problem? I love my car.
Please any suggestions or insights would be great.
Answer: 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 Dodge 3500 Ram
mileage: 102,000. My son's truck drives poorly and is
driving me nuts. The truck chugs as if rich and has low
power and poor mileage. The EGR appears to work
correctly. I can see the pintle move as the engine is
revved. Adding vacuum at idle kills the engine. Oxygen
sensor replaced 3 times! Still getting "too rich / too
lean" codes. TPS, Map, CTS, all pass tests or have been
replaced. Where to go now?
Answer: Check for a failing fuel
pump, check fuel pressure it should be between 55 - 65
psi. If not replace
fuel pump with new to recheck system.
Question: 2003 Chevrolet Express
1500 mileage: 81,000. I swear my van is haunted. This
isn't the first incident, but it's the most recent.
Perhaps you have a clue as to what's going on. Monday
morning, the "service engine soon" light comes on,
within 15 seconds of starting the van. At first, there's
no noticeable degradation in performance. After it warms
up, it seems to be running a bit rough. Also seems to be
getting just a bit warmer than normal. Drove it to work
this way, but decided when I got there to take it to a
shop. I took it to a local shop near where I work. Their
computer scanner indicated that the car needed an oxygen
sensor and an ignition module. Not knowing what an
ignition module was, I remarked that the van started and
ran, so I couldn't understand how an ignition module
would be the problem. I asked them to replace the O2
sensor and change the oil. When they were done, the car
behaved exactly the same - the "service engine soon"
light still came on, and it still ran rough. Not wanting
to be further taken advantage of at that shop, I took
the car to a different shop near where I live, the next
day (perhaps that was my biggest mistake). They
confirmed that the codes indicated that an ignition
module was required.
After asking them to make sure it wasn't something
simple like a spark plug wire, and after waiting an
entire day for them to look at the spark plug wires, I
told them to replace the module. They did, and the car
STILL did the same thing: service engine soon light is
on, runs rough, and the computer codes STILL indicate it
needed an ignition module. I had them reinstall the
original module and RAN away from their store as fast as
I could. I should have known better than to take the car
to the same shop anyway, but I never imagined it would
really be a tough nut to crack. So, my question is, have
you guys ever heard of a similar situation? That is, a
computer indicates two parts need replacing, you replace
them, and the problem still exists. The code for the
ignition module still returns even after being cleared
multiple times (and the battery being unplugged). The
service engine soon light still comes on, and it still
runs rough. Spookier still, the light doesn't always
stay on. This evening after work, my wife took the car
on a couple errands. After she returned, I took the car
out. The 'service engine soon' light DID NOT COME ON for
a while. I only drove the car 3 or 4 miles, and just as
I pulled up into my driveway, the light came on again.
Also, while it was not lit, the car wasn't running rough
any more... it seemed to run normally. Spooky, no? Any
ideas?
Answer: It sounds like
your
fuel pump is starting to fail and needs to the
replaced to repair problem. Replace with new to recheck
system.
Question:
2001 Pontiac Sunfire, miles: 89,900. Car
starts fine, drives fine for a few minutes
in the morning, however after a while any
load on the engine causes it to jerk
violently (I bit right through my tongue -
ouch). Spark plugs changed within the last
month. Had it to three shops so far, codes
come up. Happens at all speeds, 0-90 mph
depending on load. From stop, stalls
frequently, unless I floor it, in which case
I waste tire longevity, risk tickets, and
when it jerks violently, it's worse than
usual. They've checked for vacuum leaks,
changed a few vacuum lines, changes nothing.
Any help would be greatly appreciated, as I
live 102 kms from work, and the drive is
made excruciatingly long because of all the
hills, and if it always feels like this, I
don't want to bite through my tongue again.
Answer: It sounds like
you have a
ignition coil housing that is starting to fail,
replace with new to recheck system.
Question: 2002 Ford
Thunderbird mileage: 86,000. For the past 6 months I
noticed that as I accelerate lightly and the car reaches
above 35 mph if I hold the accelerator steady the rpm
slowly decrease and the engine begins to vibrate until I
let go of the pedal a bit and give gas again. During the
winter when it's cold, the car would run well until it
warms up. I changed all filters, and many people tell me
that it could be the EGR valve. Should I try to clean it
or replace it? It feels as if the engine is losing power
during cruising condition but while driving with full
acceleration the car runs fine.
Answer: It sound like you
need a major tune up
including
spark plugs,
spark plug wires,
fuel filter and
air filter. Replace as needed
to repair problem.
Question: 2003
Saab 9-5 Wagon I4 Aero mileage: 82,000. The problem with
the car is that when you step on the gas it goes to
about 15 then it loses power. My daughter says it spits
and sputters. It seems like it is not getting fuel.
Could bad gas cause this? We have changed the fuel
filter, plugs, wires, and checked the fuel pump. We put
some fuel injector cleaner in the gas tank and my
daughter said this seems to be helping but it still is
not running right. Any advice you can give me would be
appreciated. Is it difficult to change the fuel
injectors if that is the problem?
Answer: Check the
catalytic converter for blockage. It sounds like the
catalytic converter has failed and is blocking the
exhaust system. Replace
catalytic converter with new to recheck system.
Question: 2002
Ford Mustang mileage: 90,000. Hi guys.. I have seen
other articles here with VERY similar symptoms, so I
apologize for a repeat, but here goes, two problems. The
car starts very well, hot or cold, idles pretty good
when cold however pretty rough when hot. The idle when
the car is sitting still is about 550 RPM, but if I let
the car roll in neutral 5-10 MPH down hill, the idle
jumps to about 2000 without touching the accelerator
(note - it also smoothes out). Once I push the brakes
and slow the car back to 0 Mph the idle settles into a
rough 550 RPM or so. This symptom is very consistent and
reproducible. The second issue is occasionally the car
flat out dies. When it's cold and I can stay moving
(i.e. Freeway 55 MPH and no traffic) it runs great. Once
I have stopped a few times either in traffic or just
around town, it will die unexpectedly. The only recourse
is to put the car in neutral or park, turn the key off
and start. It always starts right up. It does sometimes
die again immediately after starting, other times, away
I go down the road. Any help on either or both of these
problems would be appreciated.
Answer: You have
a
idle air control motor that is malfunctioning and
needs to be replaced. Replace with new to recheck
system.
Question: 2002
Chevrolet S10 Blazer, mileage: 85,899. It has been
running rough lately and a lot of fuel has been coming
out of the tailpipe and the smell of fuel is very
extreme. I have had it put on the computer to check
everything. My husband has changed all the spark plugs;
the left side was bad, the right side was good. We even
had the fuel injector cleaned. But when we did this it
really started to run rough. Any suggestions on what may
be causing the problem? I am putting too much money out
for fuel lately.
Answer: Check the
fuel pressure regulator. You will probably find that the
diaphragm has ruptured allowing raw gas to be drawn into
the engine. To repair replace
fuel pressure regulator with new to recheck system.
Question: 1999
Toyota 4Runner mileage: 74,000. My 4Runner has started
to miss/stumble when accelerating, doesn't seem to
miss/stumble once you reach a constant speed, doesn't
miss/skip when idling, just had it tuned up not to long
ago (it should not need another one this soon) when
going up hills there is a strong smell like
sulfur/rotten eggs, I think it's my catalytic converter,
short of replacing it is there anyway to unplug one?
Please help, my husband says it isn't the catalytic
converter, could it just be a problem with fuel mixture,
it is fuel injected.
Answer: It
appears you may have a fuel pressure regulator. Remove
vacuum line to check for the presents of fuel. If so
replace with new to recheck system. This is also causing
the smell out of the exhaust.
Question: 1998 Nissan
Sentra mileage: 120,000. Car sputters and jerks/lurches
in a rhythmic fashion (like I'm revving the engine even
though I am applying constant pressure to the
accelerator). Typically does it when I get to above 40
mph, but has done it accelerating from a dead stop and
other speeds as well. Also, doesn't do it all the time.
Have changed fuel filter & replaced air flow sensor.
Nothing. Mechanic has said it is neither "gunk"/moisture
in the gas tank, nor fuel injector problems. We are at
the point of fishing...HELP!
Answer:
Your car is ready for a tune up including
spark plugs,
spark plug wires,
fuel filter and
air filter. Replace as needed to repair problem.
Question: 2002 Cadillac
Seville mileage: 97,000. I took the car to the Cadillac
dealer and they performed a 100,000-mile tune up which
consisted of replacing the spark plugs, and fuel filter.
They also performed a de-carbonization service and
serviced the E.G.R. and throttle body parts. The engine
continued to run rough and when I took it back they
re-secured a coil control wire and performed idle learn.
The engine continued to run rough, so I took it back to
the dealer again. This time they stated that a spark
plug was defective causing an intermittent misfire. They
replaced No. 1 plug, scoped ignition system, tested
injector output and ran complete fuel systems test. All
OK They stated vacuum gage fluctuated at idle; fuel
mixture is lean at idle. Also stated that an internal
problem may exist at valve guides. I was not satisfied
with their analysis as the engine continued to run
rough. I took the car to a local mechanic with 30 years
experience and asked him to have a go at it. The engine
still runs rough! I would appreciate your input as to
what may be causing the problem.
Answer: Check the
cylinder #1 compression if it is over 110 pounds. Try
replacing your #1 cylinder
fuel injector. If under 110 pound there is some
internal engine damage and a engine inspection is
required.
Question: 2004 Nissan
Xterra 4WD V6 mileage: 58,000. My question is this. I
have been having some trouble with my truck sputtering
very badly. It really acts like it is not burning all
the gas. I changed the spark plugs and fuel filter. This
did not help. Then I changed the 02 sensor. This did not
help either. There is a really bad exhaust smell, like
un-burnt fuel and there is some really black suit all
over the back of the car. The car does not run hot, but
the exhaust pipe is hotter than normal. One time
recently the catalytic converter light came on. Could it
be a problem with my ignition coil or something else? I
am sure that the fuel is getting there ok, but I just
don't think it is being fully burnt. Please help. Any
help or advice you can give will be greatly appreciated.
Thank you
Answer: It sounds
like your
EGR valve (exhaust gas recirculation valve) needs
replacing. Replace with new to recheck system.
Question: 2001 Dodge
Neon mileage: 94,000. Engine is running rough and at
times, producing very little power. I took it to an
authorized service dealer for diagnosis. They said the
"upstream oxygen sensor" has failed and needs to be
replaced. That sounded fine to me. Next, citing the
mileage of the car, the guy earnestly mentioned that the
timing belt should be replaced. I understand the
implications of a failed timing belt but I was rather
surprised that it would need replacing at only 64,000
miles. Any thoughts?
Answer: In most
cases the manufacture recommend the timing belt be
replaced every 60,000 miles. And when the timing belt
drives the water pump replace the water pump also.
Question: 2001
Buick Park Avenue mileage: 104,000. Problem, About 45
mph when converter clutch (T.C.C.) comes on, car starts
jerking and bucking hard. Acts like bad ignition module
under engine load. When taking off from a stop or
trying to maintain freeway speed, car keeps going
slower. More gas given, slower it went. Acted like a
carbureted engine with a bad accelerator pump. Then it
would suddenly take off. The next time you stopped
and/or if you turned the a/c or defrost on, same thing
again - only much worse. Replaced throttle position
sensor (T.P.S.) Replaced oxygen sensor, fuel
filter, fuel pump relay and had injector cleaned. These
are all related to one common reason - these problems
only happen when it rains. I have checked all the
wiring, can't find and exposed or corroded wires or
connections, checked ECM - dry as a bone. After it quits
raining and dries up car runs great. HELP!
Answer:
Your car is ready for a tune up including spark plugs,
spark plug wires, fuel filter and air filter. Replace as
needed to repair problem.
