throttle stop screw

I am back to daily driving my Tacoma for a few weeks and have noticed a rough idle for <30 seconds during a cold start. The pedal is stiff, hard to push and have read that I need to clean the throttle body. I was in the process of seeing what else could be causing this rough idle and noticed a screw is missing from the throttle assembly. This is for a 97 2rz.

I found the following thread that is similar to my problem.

http://www.tacomaworld.com/forum/1st-gen-tacomas/111440-throttle-body-adjustment.html

Where can I find the screw that goes there or should I just find one that will fit there?

How far away is the screw supposed to be from the valve when the engine is off?

Does anyone else have pictures they can share?

 

I did manage to find a screw to put there and have been adjusting it to where i think it should be. However, this has not solved the problem of odd idling. I removed the throttle and cleaned it, but now it idles worse and gave me check engine codes. PO300, PO301, PO302, PO303, PO304.

I can hear a loud hissing sound near the egr valve. I noticed I had pretty much all the vacuum hoses cracked. I changed them all hoping this would solve the problem, but it hasn't. It idles a bit better, but the hissing sound is still there and still idles rough. What else can this be? I have parked my truck and am daily driving my car, but need the taco to run properly.

The fuel filter, spark plugs, distributor cap, rotor are brand new and were installed a few hundred miles before cleaning the throttle body. The rough idle and engine codes began after removing, cleaning, and installing the throttle body.

 

I would say you still have a vacuum leak somewhere.

 

Use a 2-foot length of vacuum line as a stethascope, and try to locate that vacuum (hissing sound) leak.

 

Here is a photo of my throttle stop. There is no gap when cold and not running. Actually, mine is adjusted so that its beyond 0". The 'dash pot' strut is holding the throttle open a bit. Mine may need adjusting, I'll have to research it.

 

Thanks for all the replies guys. I also read about disconnecting the battery to allow the computer to reset itself now that the tb is free from gunk. I am going to inspect it again and see what I find.

 

Problem solved guys! I made a rookie mistake and noticed something when I removed the throttle body bolts/nuts. I installed the gasket upside down and was not sealing properly. I reset the check engine light and she started up perfect. At least I was able to catch several bad vacuum hoses from this ordeal and now have a clean throttle. Thanks to all the replies.

 

The rough idle on a cold start continued and eventually lead to me losing coolant. I would top of the overflow tank and would have to refill it every few weeks. I eventually started looking around, pulled the plugs, and plug number 3 was wet. I took it somewhere locally and the headgasket ended up being bad.

The head was removed, checked and was told it had cracks between the valves. I went to go see the headgasket and head myself, and there were minor cracks between the valves for three cylinders. The truck never overheated though, but I did also notice that coolant was forced out of the upper radiator tank seal before taking it in.

The truck has 224,000 miles and I have been the owner since 67,000 miles. This is the first major repair, other than a busted differential that was from abuse. I opted to get a rebuilt head since nothing else is wrong with the truck and it does not burn oil. I told them to leave the timing chain and water pump alone.

I did notice that I hadn't changed the coolant in 5 years (my mistake) and never had the valves adjusted. So perhaps all this contributed to this issue. The Tacoma is back on the road though.

 

These things happen. Sounds like your on the right track and will be up and running in no time. Laterz

 

I still have the problem of loosing coolant. I have kept a record of miles driven since I picked up the truck from the shop. I fill the coolant recovery tank to the full line and 200 miles later the coolant is at the empty line or lower. It does not leak onto the ground and cannot see any leaks. Here is what was changed with the head job:

new headgasket set
remanufactured cylinder head
spark plugs

I had noticed that the heater control valve was leaking and I replaced it with a toyota part. I also changed the 18 year old heater hoses/coolant bypass hoses and it still continues to lose coolant. The coolant hoses are new and thermostat/gasket.

The water pump and heater core are original, 224k miles. I checked the passenger floor and its dry. I also check the plugs a few weeks ago and they are dry.

I will be taking the truck back to the shop because they didn't fix the problem of losing coolant. Anyone have any idea what it could be? It doesn't overheat.

 

You could have a pin-hole leak at the top of the radiator. It would allow vapor to escape continuously while the engine is hot, gradually losing coolant. I had that issue with a honda I used to have. No liquid coolant was leaking but still loosing coolant.

 

Usually, cracks between 3 sets is getting damn hot,,at some point in time. Could have had a gauge or sender giving out false signals,,or still doing that.

The radiator was pressure and flow tested?. You say you seen coolant by the upper tank seal.

Where is your radiator coolant level when you check it cold thru the neck.

Heater puts out good heat?. Quick defrost and all that?.

 

I forgot to mention that the radiator is new. I installed it after picking the truck up from shop. And the recovery tank hose is new.

If the engine had gotten too hot, wouldn't it have spit out coolant from the recovery tank? This truck has never spit out coolant in the 14 years of ownership.

They had done a pressure test before they did any work and they said it was not holding pressure. But that could have been from the bad headgasket or head and not necessarily the radiator, correct? The radiator that I removed after the work was completed was the one that I believe had a damaged upper seal.

I always check the coolant level cold. The level in the radiator is always full since it sucks up coolant from the recovery tank. I swear that I actually heard coolant getting sucked into the radiator when I shut off the engine once and put my ear up to the radiator cap. The level in the recovery tank always is slightly lower each time that I drive it and check the level fully cold (I have been keeping an excel paper of level/miles). The heater/defroster works fine and puts out heat much faster than my trans am.

 

The bad radiator could have certainly contributed to the loss of pressure on that initial test. You might have it pressure tested again, after replacing just about everything,,minus the WP and heater core. A hot and cold test.

No water loss out of the water pump weep hole after a hard pull down the highway and up to temp?.

No milkshake looking oil on the dipstick,,right? If so,,bad juju with the block.

Plugs are new you posted. Similar burn color across all 4 when checked?.

 

I have checked under the engine and at the water pump after driving home and can see to signs of leaks. The oil is clean. I drained it prior to having the work done and it was clean, and so is the dipstick. The spark plugs were identical and looked normal when I removed them a few weeks ago.

 

Radiator cap was replaced I am assuming. Those can be pressure tested as well, to see if they release off pressure when they reach there set psi and just to make sure it's working properly.

You posted you heard a slight bubbling sound with your ear to the rad cap when you shut it off once, which is normal. A engine can sometimes spike in temp right after shutdown and it will push coolant out just a tiny bit. A needle in the red severe overheat will erupt like Old faithful into the coolant overflow tank upon shutdown or very shortly thereafter as the temp spikes just a bit more.

Water will be pulled from the overflow tank once the system cools and starts to pull back with vacuum from cooling down contraction,,usually just tiny little sips until the system equalizes and the radiator level is full. The rad coolant level is where it should be cold, full to the neck.

The only couple of things that could now possibly explain the coolant loss would be a cracked overflow tank,, minute crack opening only after it warms up from radiant heat. Or,,a big air bubble in the system trapped somewhere,,slowly filling up. That might be your water pulling back in to the system sound you heard when you shut it down. Pretty thin stuff since it has been ran for awhile and should have purged out with no indicated overheat.

 

I had similar issue. I replaced the radiator cap and I also replaced the hose going from the radiator to the reserve tank. Also, I put a hose clamp on the hose where it connects to the radiator from the reserve tank. Mine was leaking there. Havent had leak since. Forgot to mention I used fuel line since its stronger.

 

The radiator cap was one of the first things I changed when all this started happening before the head job. I do understand that coolant expands when hot and contracts when cool, and the level in the overflow should be the same after the cold/hot/cold cycle. However, mine will go through a cold/hot/cold cycle and the second cold cycle level will be lower than the first cold cycle level, if that makes any sense.

I hadn't thought about the overflow tank possibly cracked, but there are no signs of dried up coolant in that area. I don't thinks its air in the system either. I bled the system by turning on the heat full blast and making sure the radiator fill point was the highest point (lifted front end). I am just driving it before I take it back to make sure the pattern of coolant loss is consistant since that would indicate that the head replacement and headgakset job was not the only culprit.

Does anyone recommend using a leak detector dye to see if it's an external leak?

 

That's another possibility. Some of the coolant dyes are not compatible with certain coolants. This one here says not compatible with GM Dex-Cool.
http://www.oreillyauto.com/site/c/d....oap?ck=Search_N1786_-1_-1&pt=N1786&ppt=C0050

Never used this stuff or any dye before, never had the need. I don't know if you need a blacklight or eye goggles or whatever. Definitely do some research before you set them loose on that.