1998SR5

I need some help from the gurus. My otherwise great 98 2wd SR5 blew an engine in 06. I got a salvage motor and replaced it. Everything's been fine for over 12 months but now the one sporatic symptom I remember noticing before the engine blew has returned. After start up and "drive" selection on the slush box, the engine will surge under the throttle input for a second or two while the truck just sits there. Then, it will engage with a little bump and off it goes like normal. DOes that sound familiar to anyone and would you know the fix?

Just in case anyone things I killed it the first time: oil was changed on 4K interval, timing belt, plugs, tranny fluid, thermostat, water pump etc were all done before the first one went. I fly a 1971 Cessna 172 with my kids and truly believe in maintenance. Thank you for your consideration.

socal91runner

I seemed to remember something like this on my 1991 4runner.

It would 'hesistate' when I'd give it gas and then lurch forward and then drive smoothly after. This would occur after setting for a while (like when parked) and after going in reverse (like out of a parking space).

The problem was some type of leaking seal in the rear end/differential. The leak gummed up the rear brakes with 90-weight gear oil and caused the brake drum to bind to the brake shoes.

My mechanic replaced the seal, cleaned up the brake shoes and drum and all was well until I sold the '91 4runner.

Not sure if this is the problem you're having, but it would hurt to look at your rear brakes.

-socal

1998SR5

I'll check them. Thanks.

Adam F

I had the same problem on my 96. VERY common for this year truck.

Check the insides of your rear wheels for wetness.

BajaRunner

I don't think the axle seals would cause sputtering.

The first thing that comes to mind, since it is very common is to clean the Idle Air Control Valve (IAC). It is located right beneath the throttle body, and is cleaned in the same matter you would clean the TB. Just Take off the four bolts that hold the throttle body to the intake manifold, unhook a few hoses, and you'll find it. Try doing a search on here for some pictures.

I did this and it helped my sputtering... The valve tends to get dirty and stick.

1998SR5

I just crawled around under the read axle & didn't find any oil on the inside of the drums. I'll pull the wheels just to be sure. I've taken the day off from work to try and chase this thing down. Many thanks to everyone helping out. I'm willing to give anything a shot, but the engine doesn't seem to skip a beat. There's just a second or two where the power is not delivered to the wheels.

BajaRunner

Oh its after changing the gear? Might have something to do with tranny then. I misread your original post.

1998SR5

I hate to do it but I think I'm off to the transmission shop. The rear drums were filthy but dry as a bone. It was worth a shot.

Adam F

He never mentioned sputtering.