I have a 94 Rodeo V6,3.2 with 150K miles on. Today when I was driving
on the highway going around 70 (rpm is between 2k and 3k I think), I
noticed I start to loosing power and engine started to bucking. Then I
found the check engine light is on. Occationally the light would be off
and the car seemed to be normal again, but then it would come back and
I could felt the enging bucking and losing power. It is especially
obvious when I am driving uphill or accelerate. I have to drive below
60 and not sure what happened.
I did add gas this morning. I changed oil a couple weeks back and
replaced new air filter.
Any thoughts? Please help. Thansk!
My guess is that the light comes on because the engine is bucking. The
light doesn't appear to be an indication of a computer code. If it
were, the light would stay on all the time and never go out until the
computer was cleared.
Check the gas cap and make sure it's tight and sealing.
I have had this same problem. It's quite possibly a gas cap issue. When it
happens, if you can do it safely, pull over and take a whiff of your
exhaust. It will smell very different if your gas cap is not on tight.
When it starts bucking, take a look in your side mirror and you might see a
lot of dark smoke from the exhaust. When this happens and you crack the gas
cap, if you don't get a rush of air from breaking the vacuum, it's a gas cap
The light actually stayed on most of the time. I did stop but I did not
check the gas cap. When I started the car again, I noticed the light
was off, but I just found the car was sluggish. I did not pay attention
to the smoke thing. I was in such a rush that I rented a vehicle and
keep going. I will check that on Thursday. Hopefully it is a small
matter. Thanks for the input though...
Sorry to rain on the parade, but a loose gas cap most likely does not
cause you engine to all but die.
Don't cheat, buy a Haynes manual, read it, then check for codes. You
will have one in memory even with the light off. The computer is
hoping you'd get the idea to perform proper maintenance before the year
2100 rolls on by...
I beg to disagree. I have experienced this phenomenon on several occasions.
Somebody stole my cap and when I was driving home, the engine ran like crap
and would die when I hit a red light. I was getting a lot of dark smoke
from the exhaust so I thought perhaps I had bad gas. When I went to refuel,
I noticed the cap gone. Replaced it and the problem went away. The issue I
am having is that the new cap doesn't always get a good seal and the problem
recurs from time to time. The Fix...remove the cap and screw it on again.
Works like a champ.
Certainly there could be other things going on here and a proper diagnosis
should include checking for trouble codes.
Thanks for all the input.
So I came back and got in my car again, which had sit on the parking
lot for 4 days. I checked the gas cap and it seemed to be perfect,
because when I opened it I heard the sound of pressure release. I
tightened it up again anyway.I checked the exhaust pipe and sure it was
dirty, lots of fumes and my finger is all black. LOL...
Anyway, I drove 110 miles home and the car is smooth and the light did
not bother to come on once. A few uphill I was actually hitting 4000
rpm. I am still thinking to pull the code when I have time, so I could
know what happened. But I hope myabe it is just becoz bad gas or
I 'll let y'all know.
1. Have you replaced the fuel filter? or do you know when it was last
replaced? I had a situation when I was on 395 in the middle of nowhere
and the car seemingly hesitated/bucked/etc. Pulled into an all night
auto parts store and replaced the fuel filter. Everything ran fine.
2. I've also read about the oxygen sensor on Isuzu's. Have you
replaced it? or do you know when it was last replaced?
I believe I had a new oil filter when I changed oil a couple weeks
back. I have not replaced oxygen sensor for a at least 3 years,40 k
Anyway I went to AutoZone today try to have my engine code read. The
guy came out and told me he could not read it. He said the adapter is
different, and he said AutoZone's reader only has one adapter fits all.
Is that true?
Not sure about the reader, but an Isuzu dealer may be able to give you
a diagnosis service at a reasonable cost.
But about the fuel filter... it is different than an oil filter.
Though, it would not cause your check engine light to come on as I
don't believe it is monitored. I guess it is possible that maybe it
could come on because of an irregular gas flow causing other issues,
thus the light. Replacing it is a simple process that only requires 2
basic clamps on the fuel hose (to prevent gas from spilling) and your
hands. If you are not comfortable doing it, any service station can do
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