Mechanics

CHECK ENGINE LIGHT AT SOME SPEED/GEAR COMBINATIONS

1995 Isuzu Rodeo • 4 cylinder 2WD Manual • 175,000 miles

Dear 2 Car Pros:
Mi 1995.5 Isuzu: 2 wheel drive, 4 cil, 2.6 lts. 180,000 miles keeps showing "check engine light" whenever I am riding at 30 to 40 mph in 3rd gear, 40 to 50 mph in 4th gear and 50 to 60 mph in 5th gear. At the same time, it can't pick up speed when this happens.
However, if I lift the foot from the gas pedal the light turns off and when I press it again it works fine for several minutes, until it lights up again if I didn't speed up.
It also turns off if I floor the gas pedal and the engine revs up (with a strange noise) to the upper speed shown above.
My mechanic doesn't find anything wrong with the engine, and since the light doesn't remain on, he can't retrieve any codes.
It only does this (light on and power diminished) within those speeds in those gears, and it's very bothering not to rely in a quick response, as I had for many years.
Please help, this problem have been going on for 3 or 4 months already.
Avatar
Taruno
July 25, 2011.




You need to get a scan done to extract the fault codes as indicated by the check light, do this first and post the codes here for further assistance.

Mhpautos
Jul 25, 2011.
Who does these scans?
And the light being off (except on those speed/gear situations)doesn't prevent the computer to show any fault codes?
I am an ignorant in the subject, I only know (and trust) one mechanic and he told me he could not read it.
I am trying to find out before having to resort to the dealer, who would cost me half the value of the car.

Tiny
Taruno
Jul 25, 2011.
Many larger parts stores do scans, but they don't often know exactly what they are doing, this should be done by a qualified mechanic, if your can't he may be able to suggest one he knows to do it.

Mhpautos
Jul 25, 2011.
I am a little disappointed with the answers. That I needed a scan I knew before asking the question, and that a qualified mechanic (Isuzu) will do it I also knew. I asked the question to get an idea of what could be the problem, not to refer me back to the dealer mechanic; which was what I was trying to avoid.
But well, have a dinner with my contribution, anyway.

Tiny
Taruno
Jul 25, 2011.
You have a check engine light On-its a must to have it scanned for code/s, this is the starting point of diagnosis

You can try testing the throttle and vehicle speed sensors
AD

Tiny
Rasmataz
Jul 25, 2011.

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