4k rpm then sputter, choke, backfire!

[brian2sun]

Damn that sucks. I would probably go the used route because new ECMs aren't cheap at all. Maybe a salvage yard would be your best bet. Luckily, it's not a common problem so the chances of getting a used one that will still last a long time are very good (at least I would think).

Well, if you only paid $1500, put $200 into tune up stuff, and have to spend say $500 on an ECM (just a wild guess), $2200 is still an awesome price for a good running '98 4Runner w/ 110K. If this takes care of it, it's worth way more than that in good running order. You may want to spend the $70 or whatever to take it to the dealer first and have them diagnose the ECM for sure, but I think kball is right. Just something to consider.

 

[19984runner]

It is more than worth even another grand in it, I love it when your boss decides to leave his wife and doesnt want her to have the 4runner in the divorce, yet needs fast cash to leave her. Its a one owner sr5 loaded, power everything, dark green, cruise, seems to have the limited rims, the 16inchers that have 265/70/16 tires, cd player that the kids installed quarters into, so thats another fix, BUT has new timing belt, harmonic balancer, belts, but ac works great. just cant rev above 4k. Just read a post from a guy who had a t-100 with the 3.4 that had the same problem, he took it to the dealer, they said the limiter had moved, reset it and he was good. Im gonna take it in next week, let them know that Im pretty car savvy, so games arent gonna work, have them run the TPS ranges, mass air, tranny range sensor, then tell them to reset all settings in the ecm to factory spec, then look for a bad ecm ground. Truck has NO rust, just some hail dents, or, as i live in the STL, probably 9mm rounds fell from the city and dented my hood in a couple places.We call that hail. Too bad they wont let me "hail" my own 30-06 rounds back to the east. Probably against the hague convention anyways...:ak472:

 

[steezemcqueen]

seriously dude...are my posts invisible or something???

 

[19984runner]

I read em greenmonster, Im gonna have the ecu looked at tuesday by a toyota tech afterhours, ill slip him 20 bucks, and if needed, he will reflash it for me.

 

[bmcnutt]

did you find your problem ?

 

[JR Sully]

I had the EXACT same problem with my 2000 that I purchased last month.(approx. 163000 miles).

**The problem was resolved by resetting the crankshaft timing pulley to the proper location on the crankshaft snout.** (sproket with crank position sensor flange on the back).

I went into the problem with the mindset that maybe a basic tune-up would help the issue, as it did feel like a fuel delivery problem when you hit 4K and sputters, chokes like it is hitting fuel cut.

So I started with the basics:
fuel filter
plugs
wires
air filter

took it out for a drive.... ran smoother at idle, but no improvement on the 4k rpm brick wall problem.

So I took it back to my garage and started in on the rest of the tune-up, which consisted of T-belt, WP and tensioner and pulleys.

Eventually got to the infamous crank bolt... With my home made SST to hold the pulley stationary, I put a breaker bar on the bolt and got ready to give it hell....

Much to my surprise, the crank bolt was barely tight... From the research I have done on here, It is apparent that this is not an uncommon occurrence for techs or DIY's to skip the very important step of properly torquing the crank bolt spec for timing belt or water pump jobs (they might just guess at the torque with a high power impact wrench and call it good). As a result, if/when the bolt comes loose, all sorts of problems can arise. (worst of all, the snout of the crank can potentially break off)

In my case, once I got the harmonic balancer and bottom timing cover off, I immediately recognized that the crankshaft pulley (sproket for timing belt) was sitting forward from the main seal on the crank by approximately 0.5". The sensor teeth on the sproket that align with the crank position sensor pickup were sitting at the very edge. It had shifted due to a lack of torque on the crank bolt, and thus probably throwing the computer irregular readings at higher rpm. "Well, there's your problem", I thought.

To get the sproket off to reset it, however, was a NIGHTMARE! It was pretty well stuck on the shaft with rust. Using a puller, TONS of PB Blaster, attempting to walk it off with the two screwdriver trick, heating it up with a propane torch and hitting it with a brass hammer still brought no glory. After breaking off a few of the sensor teeth from trying to pry it off :redbrick:, I let it soak over night with PB and went to Toyota the next day to get a replacement part. Still unsure how I would be able to get the now damaged sprocket off, I contemplated putting an air chisel to it and cutting through it. But after fussing with it some more the next day, I was finally able to work it back and forth and get it off.

Got it all buttoned up, and now it runs like a raped ape all the way up to redline! :guitar3:

Moral of the story: PROPERLY TORQUE THE CRANK BOLT when doing service that requires removing it!!

BR,

Joe

 

[ChildrenOfBodom]

Actually makes sense because his harmonic balancer was replaced.

Wonder if he's gotten it figured out yet.

 

[jcolt00]

tacoma timing belt replaced revs at 4000 rpm

is all you had to do was tighten the crank pully to resolve this