Ummm What???

[Jtwo]

OK, I feel like ghost riding my 4runner off a cliff......

Had to replace the fan clutch sub assembly so I took it to my mech. Well on the way there I went to pass a car (normally not a prob) but instead got it around 4krpm and it just starts stuttering bad, almost sounds like some popping going on too.

So I have my mech look at that too since it's going to be there.

Replaced the plugs and 1 coil pack thinking that would be the problem. Nope, still getting the same results!

This is what happens:
Steady acceleration to 4k rpm, engine stutters (kinda like hitting the rev limiter)
Floor it to 4k rpm, engine stutters, get popping noises (like a miss fire/back fire) acts like I'm pinging the rev limiter......

My gas mileage went to complete crap too........

I'm at a total loss, getting very frustrated, and tired of spending money on it.

and advise would be great!

-Seph


EDIT* 1999 T4R, SR5, 4WD, Auto, has 110K on it

 

[polvadis]

Had a very similar experience with my mom's '98 4Runner, turned out to be fuel injectors.

Had all six injectors cleaned and some $700+ dollars later the car drives like new again. My mechanic just took out the injectors and sent them out to some "cleaning company". They said 1 was really bad, 2 others were bad(dirty), but all 6 required cleaning. Either way, it was best to do them all at once since any mechanic will charge you a lot to take them out, one or six, same price.

Also, for some reason my fuel filter was really bad, although some other mechanic was supposed to replace it many thousand miles ago... don't think he did.

 

[Jtwo]

Thanks for the reply, I just got done changing the fuel filter and still have the same problem. I really hope its not the injectors but I guess I'll have to get them looked at.....

I just changed the fan clutch sub assembly yesterday (part alone cost 500.00) then add labor. So, I'm a little bummed after dropping so much and still having a totally different problem!

I know that the plugs were way overdue, since I bought used I don't think they've ever been changed. Got them changed and replaced one coil, I might have to change the wires. I'm thinking I'll bring it in on Monday.........there goes new tires!

-Seph

 

[Jtwo]

Quick update......

Bought new plugs and new wires, unplugged the neg terminal to reset the ecu.

Swapped the old stuff for the new stuff then reconnected the negative.

Started up, ran it for about 15 minutes while I retuned my stereo.....Reved it...same problem, reved it again and it seemed to get better (almost like blowing the carbon) Reved it again, and it did just fine...so I took it for a spin, ran better than before!

So I cleaned it, waxed it, and shinned it up.....then I went to run it again and back to square one. Misfiring again, not going past 4k rpm.....whats the deal?

I'm stumped...........

 

[ProMed]

So I cleaned it, waxed it, and shinned it up.....then I went to run it again and back to square one. Misfiring again, not going past 4k rpm.....whats the deal?

I'm stumped........... [/B]

As polvadis said above, it sounds like your injectors need a scrub job.

 

[KellyJ]

throw some seafoam in the PCV valve and that will clear a lot of the crud in there out. throw the rest in the tank when its almost empty and then fill it and that should help some

 

[vinnymac]

missing

Is your Check Engine Light coming on? And if it is, what code is it throwing?

 

[Darrin530]

im sure running some injector cleaner, slick 50 or some gas treatment wouldn't cure it, but it wouldn't be a bad idea

 

[polvadis]

im sure running some injector cleaner, slick 50 or some gas treatment wouldn't cure it, but it wouldn't be a bad idea

That's what I thought until my mechanic said "cleaners" actually do more damage than good. He said that cleaners weaken the seals and do some other bad stuff I don't remember at the moment.

From a logical point of view it sort of makes sense, if something's failing cause it's dirty adding a little extra something to the fuel can't help all that much... but that's just my logic, anyway.

 

[Jtwo]

Not throwing any codes which is why I'm having such a hard time.

I'm going to change the other 2 coil packs as I've only changed the one and see if that will clear it up.......

It runs perfect below 4k rpm its just when I go above that when I start having probs....

Thanks for the info.......keep em coming

-J

 

[hellbound]

had same problem

I agree with the injector theory. I had a simuliar problem, took it to my local Toyota dealer, they charged 75 to diagnose that they needed to do a 150 buck injector clean wich consisted of removing the two caps over the vacume lines on top of the EFI minfold and spraying injector cleaner in there with the engine running. This worked for a little bit until it ran rough again, and finaly popped a code. Missfire cylinder 6. So took it back in, 300 bucks later (they cut me a break because I have already dished out 225) and they replaced the fuel injector on cylinder 6. Ran like a top after that!

So here is what I learned:

Do what you can first... SEAFOAM is the best (IMO) out there. run your tank almost empty, dump the bottle in there, and fill up. I now run a tank with seafoam in there once a year

If you pop a code, get it read. If the code points to on cylinder, replace the injector yourself if you have the skills. (I should have done this) The injectors run about 100

Also, another learning I have from a different experience, If you use premium gas in the winter, DONT! With gas prices the way they are, in colder climates when prices go up the premium gas does not get bought as much and sits in storage tanks at the gas stations and actually collects water in with the gas. A friend had issues and found 20% water in his gas tank! he good old toyotas run fine with regular unleaded gas.


my 2 1/2 cents

 

[Jtwo]

At last......

Ok after a month of trying to figure out what the deal was with my runner we finally figured it out.

Thought it was either the cam sensor, crank angle sensor, or the ECM. I was really hoping it wasn't the ECM but it turned out to be just that!

So, we replaced the ECM and she runs like a charm! I also replaced a tie rod....hopefully I'll get into a lift and new treads by next month.

Thanks for all the info!

-J