03 Rodeo over revving, sounds loud, like it's stuck in gear

[Jimysan]

This is driving me nuts...

OK, never had any issues with my 03 Rodeo.

Then one day I start it up, and it sounds like my foot is half-way down
on the accelerator... it's over-revving and now it's LOUD...

usually she starts up and purrs nice and smooth, and now it's loud and
even when I take off it sounds like it's stuck in 2nd gear, although the
shifting is normal.

How else can I explain this?
Normal... smooth running... usual engine noise.. runs great
Now: Sounds like I've stomped on the gas... over LOUD, running hard
and losing gas mileage.

If anyone can help I'll buy the drinks!

Jim

[trooperbc]

the easy solution is the simple one, that pops to mind. check that the stupid rubber boot that goes over the accelerator cable and housing at the throttle body end hasn't 'melted' into goo and is jamming open the accelerator by not allowing it to return. it actually was an isuzu official recall.

//bc

[andrew_j]

yup trooper's spot on. mine did it and the throttle would be really hard to press and get stuck. i almsot ran my friend down cause of it getting stuck. cut it off with a razor blade 10'000 miles ago and haven't had any problems. should fix your issue. cheers.

[Jimysan]

Well, like I said, it's hard to explain, but

no, the accelerator isn't sticking... it returns to position like normal.

When the car starts it is idling so high, and then when driving it
the high idle just gets higher... almost as if you shortened the
accelerator cable by an inch... everythings going higher revs, but the
accelerator acts normally.

Told ya it was drivin' me nuts !!!!!

[XR400R]

Interesting. Guess I don't understand the earlier suggestions regarding the accelerator cable. I thought all 2nd gen Rodeo's had Drive-By-Wire? I know mine does. I must be misunderstanding the suggestions.

Anyhow, this sounds suspiciously like an intermittant leak in throttle body or intake plenum gasket. You sure that's not it? Spray some carb cleaner or propane at junctures & see if idle changes, perhaps while trying to jiggle TB or plenum?

[95passport]

auto?
what is the tach saying for rpms is it over revving or not
it sounds like you have a transmission problem to me, yet you say its shifting normally.

if the rpms are going too high its transmission related either internal or computer related.

or perhaps I don't understand the symptoms.

does it make the same noise in nuetral?

[95passport]

oh i think i understand now

you just have a really really high idle correct?

it's not revving very high its just starting way too high

found this on search
Answer
Hello and thanks for the question...I'll try to help.
WHat I would suggest you look for is a vac leak, external or internal in the engine. The external leaks are usually vac lines, or valves that are cracked. The internal leaks to check are the plenum gasket (the big silver thing that holds the throttle body), PCV valve, and EGR valve.
I would also suggest that you disconnect the negative battery cable and reset the idle strategy. Wait for 10-15 minutes before reconnecting it. Then dive the vehicle for 5-10 miles, going from 0-55 mph.
You might also want to clean out the throttle body with a mild cleaner on a rag.
Hope this helps,
Erik

/\
i would try all that...even though it was for a different vehicle, I searched for extremely high idle.

good luck
john

[amigo-2k]

Originally Posted by trooperbc

the easy solution is the simple one, that pops to mind. check that the stupid rubber boot that goes over the accelerator cable and housing at the throttle body end hasn't 'melted' into goo and is jamming open the accelerator by not allowing it to return. it actually was an isuzu official recall.

//bc

in 2000 they started the drive by wire system, so there is no throttle cable.

[trooperbc]

Originally Posted by amigo-2k

in 2000 they started the drive by wire system, so there is no throttle cable.

so i guess you're saying it's a good idea to note the year of the vehicle with the problem . . .

in my defense, i would if the year had only appeared in the Title.
(oh, nevermind)

i mean, if the year had only appeared in the body of the text.
(oh. nevermind)

i mean, i would if the year had appeared with the other vehicle info in the poster's signature.

yeah, that's it. if only the year had appeared with the other vehicle info in the poster's signature line. ....


//bc

[Ramblin Fever]

When you start the truck, or rather 2-3 seconds after starting it, what is your RPM's at that point??

Also, are we talking a stick or automatic truck?

[srpope80]

Gentlemen,

Had the exact same thing happen to mine and it was basically because I went so long without cleaning the throttle body. The butterfly in the T.B. is so tight the carbon buildup around would not let it return fully. I would get a insane idle 1500-2000 RPM, etc. 1 can of carb cleaner to the T.B. mouth and butterfly and BAAAM. It's good as new.

[Jimysan]

Originally Posted by Ramblin Fever

When you start the truck, or rather 2-3 seconds after starting it, what is your RPM's at that point??

Also, are we talking a stick or automatic truck?

This is about as close to describing the problem as there is... better than I described it.

You know how when you start the Rodeo, you get that LOUD revving noise and then after 5-10 seconds it settles down into that nice smooth running noise and then runs just great... well mine STAYS at the loud revving noise. Even after you put it in gear and take off... everything has that loud
revving noise.

The rpm's SEEM to be normal... and she's an automatic.

Also, as a side... is there an online manual for an 03 anywhere out there?
I only did a quick search, but didn't find one yet.

[99 Fronty]

If the rpm seems normal would this be the radiator fan playing up? I don't even know if this is clutch or electric fan but if it is normally loud when you start up that could be the fan howling until the clutch activates. Maybe now it is defective and staying on.

I know when my missus drives into the garage with the air-con running it sounds like the engine is reving but it's the fan.

'99

[Ramblin Fever]

Yes, check your fan clutch - Isuzu's are loud generally anyway, their fans. But yours may be stuck on.

[dynastykid22]

Have you tried the throttle position sensor ???