Greetings from 'old' Newbie' and questions ...

[nrgetic99]

Greetings to my pals from other boards and my new friends here at UY !

I got invited by a Mod so I will automatically adopt a superior tone in my posts :D

Anyhoo, minor issue with my 98 3.4 Ltd 4runner Auto.
Drove from VA down to the Outer Banks of NC for some R&R.

About 2 hrs in, I have the cruise set at 60 miles per hour (Route 158 if you know the area is a big speedtrap) and vehicle starts to miss badly. Take if off cruise, run manually at same speed (~ 1900 rpm in top) and same result.

Seems fine under acceleration but will not run right at cruising speed.

Decide I should try and make it to the beach house and check a few things, plugs are new and clean, no obvious loose wires or vac hoses.

Tank was about 1/3 full so I pick up some FI system cleaner and fill tank with Shell V -power premium (contains highest additive level of any commercial gas right now) and it seems to run fine. Before coming home, fill up again with V-power premium ands dunk rest of FI cleaner in tank. Runs just fine all the way home.

I hooked up my OBD-II tool last night, no codes or pending codes, no misfires detected.

This leads me to the following :

1. Bad Gas ?
2. Intermittent coil pack/plug wire breakdown ?
3. Clogged injectors (hence OK under full accel but struggle on low revs)

Anyone got any ideas ? I will replace plug wire (Genuine OEM only ) when funds allow

Thanks

David

P.S. Drove on the beach and got some nice comments about my deflators and low budget on board air set up... peoples faces when they see me hook up an airline under my rear bumper are worth seeing
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[Seanz0rz]

i had a problem in the 1500-1900 range on my 3.4. it would shudder and studder. i replaced the wires and plugs (plugs were OEM denso from the stealer, wires were from ngk at about 2/3 the price the stealer wanted, found em on the net.)

i took a trip up to SLO from socal here and didnt have any problems, although it was hard to get the engine to peform that way even when i DID have the problem. so far i think that fixed mine. i also had no CEL or any other indication of a misfire, it purred at idle, etc. everything was fine except for that range of RPM.

yours sounds like it might have just been a tank of bad gas. do you remember where you purchased your gas from on that tank? had the vehicle sat for an extended period of time? i know mines runs poorly on arco and other brands of discount gas. i only put shell or chevron in, unless im forced otherwise.

hope that helps! and WELCOME!

[TDiddy]

You seem to have hit the major troubleshooting possibilities. I had a rough idle issue last year, but under acceleration or cruising it was fine. that turned out to be a bad plug wire. I'm betting you'll be fine from here on out.

[Bob98SR5]

david,

good to see an old face again in our little neck of the woods. keep us updated over a few tanks of gas and report back if the same conditions are still occurring

bob

[nrgetic99]

Thanks all,

Been driving the S4 this week but will fill up tonight and report back.
I may well pick up some plug leads anyway.

David

[MTL_4runner]

Good to see you over here David!

With it being so intermittent it may be hard to pin down until it rears its head again. Run a few more tanks of gas and see if it comes back. Try looking at the timing advance, O2 sensor, TPS and MAF with your OBD if is does reappear.

[nrgetic99]

So far so good on a fresh tank of regular gas.

I will, as I said, replace plug wires as funds allow.

BTW Jamie, how can I narrow down the shopping list of things you suggested without it throwing codes ??? Wait and see I guess.

David