Was driving down the Highway & all of a sudden I had no throttle. I shut the 87 4runner down & then noticed my dash pot adjustment screw was missing but that didn't seem to be an issue. Towed it & then took a look at it when I got home.

I started it up & this time drove it around the block. The engine was running up the RPMs at weird times so I took it back home and parked it. The CPU was throwing a 11 code & it ruled out my thoughts of a bad throttle cable. Was now thinking TPS.

This afternoon I popped the hood & took of the air intake hose. Well, I found a sleeved round rubber piece stuck in the flapper on the air intake & it was causing the throttle linkage to bind up. I replaced that hose several months ago & some how must have left this rubber piece in the intake hose & it finally moved.


So I thought great, finally an easy stupid fix...WRONG!

The engine is now idling up & down or rough. I took off the vaccum hose that goes from the Air Valve to the bottom of the idle adjustment screw and it is idling better but when I put the hose back on it idles up & down.


FYI: I did have to shut the engine down several times at HIGH rpms because of that stupid rubber piece.

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Thanks!

Okay just started it up & checked the timing. The timing is good. I redjusted the air intake hose & made sure that everthing was good and tight. I have a strong vaccum coming from the end of the red vaccum hose, shown above. When I put my finger over the end of the connection below the adjust screw the engine starts idling up & down, just like it does when I have the hose connected.

I checked the diagnostics and it is not showing anymore codes (1 flash).

Any suggestions would be appreciated.

After working on the problem all day I found this post:

Now, another problem, and maybe one that people forget to check. As I already stated, I'm running a bored out TB. When the machine shop fitted a new throttle plate, they did "okay" but there were some gaps around the edges letting a little too much air through. Funny thing is I've been running this set-up for over a year with no trouble. For some reason it now wants to rear it's ugly head.

So, I filed down the spots that were too far extruded and not allowing it to fully close. I now have it to where it's as sealed as the other TB is that I have on hand. I then realized that in my case the linkage that connects the TB to the throttle parephenalia on the side of the intake plenum needed to be shortened slightly to allow the throttle plate to fully close. I noticed that the idle would stay in the 1400-1500 range unless I put pressure on the external throttle linkage, forcing it closed. Easy fix, and now the idle stays around 1000, which is plenty acceptable to me. But I wish I wasn't maxed out on the low side of the idle adjustment screw



So, I know I mashed on the throttle several times with that rubber piece bound up in the throttle plate. I have a feeling I bent the plate, how can i tell for sure and how do I fix it???

Desperate...

I don't know man - I'm not well versed in the throttle bodies yet, and looks like yours is an earlier one. I'd say it's possible that you may have damaged something, like the throttle plate, or more than likely threw something out of alignment like the Throttle Position Sensor. If you've got a FSM for your year then start with a throttle body inspection and throttle position sensor check. check the dashpot. Inspect the throttle opener. and adjust if necessary. I'd say look into the trottle body at the valve and if it's fully closed there should be no gaps on top or bottom. YOu might have to adjust the trottle positin sensor.

Just trying to offer some things to consider. .... (from my 93 FSM)

Alright I adjusted the TPS & it took the loping away BUT now timing is way off. I adjusted the distributor but was only able to get it back on the first timing mark (ran out of adjustment. It was about 1.5 MOA to the left off of the timing numbers before I moved distributor.

Now what? Do I pull the distributor and get TDC and then go from there?

It sounds good its just idling fast...

Okay, now that my brain had a few days I realized it has nothing to do with TDC.

After adjusting the TPS to .85 ohms at an idle the engine was just idling way to high. My timing was off by 1.5 MOA and it was out of adjustments. I adjusted the TPS to .65 ohms at idle and the engine idles nice when initially started for about 2 minutes or so...It then drops idle slightly after it warms up & starts loping.

I am about to pull my hair out! The only thing I can think of is I bent something in the throttle linkage and or the TPS was tweaked when I had the incident.

I now believe my 2.5 year old son must have put that rubber piece in the intake hose when I had it sitting on the ground for service. <img src="/forums/images/graemlins/zombie.gif" alt="" />