headgasket

Hey Yotas:

Just completed the "headgasket" fiasco.
Enjoyed the challenge and the fact that we're on the road again.
Compliments to Ted and Todd at engnbldr.com and Rock Gaskets.
Great price/quality match; fun to do business with, knowledgeable and friendly at that.

Now we're down to fine tuning the idle speed at initial start-up.
The conditions are here in soggy rain soaked western Oregon. Morning temps high 30's /low forties. Nothing extreme. Rig cranks fine, fires on cold start injector, at around 800 +/- and then drops to 400-600 rpm.

Does not die. Then when you rev it some with the gas pedal it will warm up to the point it will run at 1500 rpm and after a minute or too all is good to go.

Questions: Shouldn't it initially start at 1500 rpm and hold at a strong idle then drop. What culprits can I explore to make this thing run "Jake.?"

toytech76

Raise your base idle to spec after it is fully warm. Set it at 800 rpm when its at operating temp. Service your throttle body really well and get it nice and clean. If it is going up to higher idle when you first start it after giving it gas, you are probably looking at a misbehaving idle control speed valve. It's part of your throttle body. The 2 small coolant hoses going to it are what feed it coolant

headgasket

Toy Tech:

I have not pulled the throttle body off to do an extensive clean. I always save the TB gaskets from the head gasket set but haven't removed it in the interst of saving time with the hg repair. I am wondering what idle speed the truck should start with on cold start; I thought it was normal to rev higher until everything warmed up. It has been set with the TB Air inlet screw to 800 rpm +/- 50 rpm when warmed up and the paper clip across the terminals in the diagnostic code reader plastic box on fenderwell.

It would be helpful to know the normal rpms at different intervals of time on start-up before the 3VZE settles in to its 800 rpm warm idle mode.

I think oveall I'm just trying to alleviate the rpm drop I mentioned in first post.

Can I clean the TB without removing it. I'm sure it's gummed up.
How to would be great, pehaps a link.

TNRabbit

You can adjust the cold idle separate from the hot idle. Cold idle adjustment is on the right side of the TB as you are looking into the throat. It's a bolt/nut adjustment. Should be around 1100-1500 when cold.

Hot idle screw is on the front of the plenum, just to the left of the TB as you're looking directly into the engine bay from the front of the truck (recessed flat head screw). DO NOT connect the terminal pins for idle adjustment when hot.

headgasket

TN Rabbit:

Nice job explaining the different addjustments to a "shade" tree mechanic like meyself. Both Toy Tech and you have helped me solve what little remains to
give my new headgasket work the best chance to roll 7's or 11's as we're "on the road again."

And yes, I will make sure the paper clip is out on the cold adjustment as you mentioned. Ditto for the warm idle.

We're running the stock timing with the paper clip across TE1 and E1.

What advantage(s) can we gain from mvoing the dizzy to 12 degrees btdc. ?

I know I'm being a little conservative here at following the FSM.

I'm looking at running unleaded regular and going for fuel economy and as much extra power gains from a completly stock 4 runner.

Leaning toward a free flow cat and a new muffler to complete the headgasket "insurance policy" so to speak.

Thanks to all for your help.

headgasket

TN: I do not have the car here. Is there a page in the Throttle Body Section of my Toyota FSM manual in the section MFI System pp. EG 238-EG 245 or somewhre else I could locate the nut/bolt adjustment?

Thanks, Dave

Belize Off Road Team

yes it is supposed to idle at 1500RPM at start. and i dont know what the culprit would be, with mine it was how much pressure was in the A/C system( dont any body tell me anything else, cause thats what it was, the mechanic said it cant be that cause it does not have anything to do with the idle...) it worked for me.

TNRabbit

(Click for a larger pic)

headgasket

TN:

Thanks for the digital pics. 4Runner is back in Bend, Oregon doing wht it's supposed to be doing. Running great. I have had so much fun and I mean that debunking some of the "myths" behind the 3.0 head gasket failure.
One thing for sure, I'm learning how to get things apart and back together. I can't do 2 per day like the Toyota Technicians but am learning how to get the job down for (nearly $100) and 2-3 days of wrenching at my leisure.

I will still stand behind engnbldr's gasket set. Funny thing, in all reality all I really need is the plenuium paper gasket ($4.99 at Nappa), the intake gaskets, (can't be that much) and I can get the Toyota OEM gaskets for cost (NorthridegeToyota.com) minus 25% so that would be $86 to my doorstep (free shpg.).

With our heads being milled twice already not sure we can shave them any more, I'm going to the wrecking yards or Engine Rebuilders Supply Co.(Troutdale, Oregon) phone # 503-661-5614.
I will stock up on 2 replacement heads, get 6 new exhaust valves, mill the new heads + plus steam clean ($91)(required to do the job) pressure checked for another $30.

So as you can see for $200 and my time this is starting to not be the source of frustration it once was. I really appreciate all the great support and tips this forum provides. Builds confidence with the 3.0 slow.

Can you suggest a valve spring compessor source. We jsut used two wooden dowels and elbow pressure to do the valve removal on a tiny Tercel head.
3 VZE can't be that much different. Funny thing though one of the retaining clips went flying off; never did find that one.

toytech76

If you are gonna do that, buy the 6 exhaust valves (toyota only) and send them to the machine shop so they can pressure check your used heads, surface them and do a complete valve job. You don't wanna throw new exhaust valves on a seat that hasn't been ground or at least faced. Do them up right and they will last longer. Make sure you get the right year heads also. The early heads will work with the early years only. The late heads will work with early and late. the difference is what tbelt tensioner it uses. (spring or hydraulic) Just tell them what year yours is so youknow you have the right ones

headgasket

Toy Tech:

Your clarifications of early late 3.0 3VZE engines help. I did call Engine Rebuilders Supply from Troutdale, Oegon. I stand corrected. For a pair of used heads it is $300 per pair. He told me they are in high demand.

I would have the machine shop fit the valves as you suggest. Hand lapping wouldn't cut it. We're just trying to stretch the engine from 200,00 to
250,ooo or even 300,000 miles.

toytech76

That shouldnt be a problem. We have a customer who had, honest to god, over 600K on his original engine. Granted he had a few valve jobs but the motor went that long. Maintenance goes a long way