Ava

My Surf (a 3.0L V6 Japanese 4Runner of '93, righthand drive) misbehaves. One moment it accellerates fine, the next moment nothing much happens, besides a 'plop' from the engine compartment, until I completely floor the pedal.

When it behaves fine I get a lot of power when I bearly touch he pedal. When it doesn't behave well I need to push the pedal half way down to get a similar burst of energy from it.

The fluel consumption is going trough the roof lately (1 liter per 3,8 km, less than 9 mpg).

The car is 10 years old and in quite a good condition. It doesn't consume oil and there's no rust anywhere. But the previous owner(s) (or their garage) didn't know what they were doing. I found a few misrouted vacuum lines and also a welded shut EGR pipe. The EGR valve was connected to the fuel pressure unit via one of the VSV's.

The Haynes manual is not very detailed and/or precise because I cannot locate the color coded wires to the VSV's in the schematics. Ther are two VSV's mounted on the righthand cam cover. The top one is brown with one green and one white/red wire. The bottom VSV is green and has a pink and also a white/red wire.

My questions to the forum are:

A. Should the EGR pipe that sticks into the intake chamber be closed at the end? And if so, what is the use of a closed pipe? (On the drawing in Haynes manual it looks closed too)

B. Do any of you know which VSV is for the EGR system, and if the second one is meant for the fuel pressure unit?

C. Haynes tells me to jumper E2 and IDL on the throttle position sensor connector (the wire harness side) and then to gradually raise the engine revs. But Haynes forgets to tell what to look for. My engine interrupts (stalls) at even intervals. Is this the normal behaviour?

D. Im trying to figure out what is causing the plopping (it's probably mixture exploding in the exhaust) sound when I open the throttle. I've tried to induce it by removing the cranckcase ventilation- and AC Idle-Up tubes in order to create a leaner mixture (immitating a vacuum leak) but that doesn't seem to be it. The high fuel consumption leads me to believe there sooner is too much petrol in the mixture.

E. Then there is this so called 'Air Valve' which I cannot seem to locate. According to Haynes this valve bypasses the throttle valve when the engine is cold. According to the test from Haynes manual this valve does'n work. The manual doesn't say where this valve is located on a V6, and I cannot find it. Perhaps it's under the intake chamber, or perhaps a Japanese 4Runner doesn't have such a valve? Anyone?

Because the car can run well one day, and badly the next, I've ruled out things like glogged filters or injectors. If one of those were the case the car would run bad all the time, wouldn't it?

Hope someone can help,
Ava.

Ava

I have asked help on this forum a couple of times in the last weeks but didn't get any really helpful replies. Is there a place where the real hardcore Toyota truck driving techies hang out?

Ava.

Babypig

I too have similar probs. One day it feels like new, the next day it sounds like it needs a rebuild and idles like crap. I too have done all the tests and also had the same crappy vacuum hose problem. Seems the owner before me was fond of using electrical tape to plug up spots where there should be hoses. I might be able to take a pic of the manifold to show you where the hoses go. Mine is a Canadian spec runner and shouldn't be to different. I have chased the crappy idle problem down to wiring. I have found a couple of spots where the wiring has been worn through. The one place that I've seen on a couple of runners is on the drivers side ( your passengers side) injectors harness. The one right under the intake pipe get smushed down onto the intake and rubs thru underneath. Another thing that i figure is that the distributor may not be functioning well after 212,000 km. Might be the ignition parts are starting to go funky from all the moisture around here. Could also try the plugs. Mine has more ghosts that a scooby doo cartoon lately.

kctopher

Ava, to answer your second post I dont think its a matter of lack of tech, its a matter of asking the right question in the right forum...

We moved your post for more exposure since it could fall under both fourms (maintenance/ 4Runners, Trucks, & SUVs), you should find some leads here....

Chris

AgRunner06

I think that I may be able to help you with one of your questions. Here is an article on the TPS for the 3.0L. I hope that will help you some.

Have you checked your timing whenever it runs bad? I don't think timing is the only problem but it may point you in the right direction.

What do you mean by the EGR pipe being closed at the end? How is it welded shut?

I hope this was some help. I'll see if I can find that air valve.

Good Luck

Ava

I'll look into that. I did take a preliminary peek and spotted the same error in the V6 table (I think).

Quote:

Have you checked your timing whenever it runs bad? I don't think timing is the only problem but it may point you in the right direction.

That's a bit hard to do, but the first time I aimed a strobe at the pully I couldn't find the mark, so far off it was. Something like 45 BTDC. That cant be right; the engine would have detonated (pinging).

Quote:

What do you mean by the EGR pipe being closed at the end? How is it welded shut?

Just what I said, the end of the tube that sticks into the intake chamber has a little dome welded on it.

Quote:

I hope this was some help. I'll see if I can find that air valve.

Yes please! I can't find it. Same problem with the fuel filter. Seems that it isn't in the engine compartiment at all. I found it under the car, near the tank. At a real good position too. Next time I remove the transmission or transfer case I must remember to replace the filter. Sometimes I wonder who takes these design decisions.

Thanks 93_Runner06 (hmm, funny name)
Ava

Ava

I think I have that side workd out now. But really don't know what VSV goes to the EGR and what VSV goes to the fuel pressure valve.

Quote:

Mine is a Canadian spec runner and shouldn't be to different. I have chased the crappy idle problem down to wiring. I have found a couple of spots where the wiring has been worn through. The one place that I've seen on a couple of runners is on the drivers side ( your passengers side) injectors harness.

This might be someting to look into. If that is the case on my rig than that could explain the sudden changes in character, even while driving. But isn't there's something like about a square meter of intake chamber blocking my view? ;o)

Ava.

AgRunner06

What is this error in the table that you are talking about? I looked at the table and don't see any problems with it.

Your timing being off leads me to believe that it could be your TPS. When my TPS was bad my timing was somewhere between 1.5" and 2" away from the 15 degree advanced mark. So mine would have been about the 45 degree mark too. The dealership replaced my TPS and then adjusted my timing.

You should fix that EGR. There may be other problem that you will find once you fix it. That's probably why the previous owner did that.

I just so happen to have a Haynes manual here. I'm assuming that you have the same or similar version of the manual. If you look on pg 6-16 at the bottom right diagram it shows which VSV's go where. If that's the wrong page look in the Emissions Controls Systems section of the manual.

I looked for that air valve....and couldn't find it. Sorry. I looked around for about 30 minutes with no luck.

I hope this will help you some more.

Good Luck

Ava

>What is this error in the table that you are talking about? I looked at the table and don't see any problems with it.

Maybe I'm wrong. The Haynes repair manual has a schematic of the TPS and it has only one variable resistor. If that is true, the value in the table for VCC-E2 cannot be lower than VTE-E2. But on the picture I've seen now there is a possibillity there are more variable resistors at work.

>Your timing being off leads me to believe that it could be your TPS. When my TPS was bad my timing was somewhere between 1.5" and 2" away from the 15 degree advanced mark. So mine would have been about the 45 degree mark too. The dealership replaced my TPS and then adjusted my timing.

Then there's the little matter of the vacume driven start-device on the throttle valve, just between the valve and the TPS. That's not in any book or story about TPS I've seen, but it's on my rig. It opens the throttle a bit when the engine is off, and let's go when there is enough vacuum. In my book that means the meassuring points cannot be the ones in the book. Or do ALL 4Runners/Surfs have this device and are the positions correct when using the appropriate feelers. I adjusted TPS and timing without regard to this device and it didn't help much. I redid TPS and timing again after plugging the tube when running. Not much difference here with the first way. The timing was much better on both settings, though, but the engine apparrently doesn't respond very much to timing.

>You should fix that EGR. There may be other problem that you will find once you fix it. That's probably why the previous owner did that.

Overhere there are no laws for polution and the 0.00001 percent (give or take a few ;o)) gain it will give, the EGR system is the least of my worries.

>I just so happen to have a Haynes manual here. I'm assuming that you have the same or similar version of the manual. If you look on pg 6-16 at the bottom right diagram it shows which VSV's go where. If that's the wrong page look in the Emissions Controls Systems section of the manual.

What's wrong with this picture:
A. My manual is printed quite fat, but with a bit of figuring out I can almost guess what goes where.
B. My rig has the VSV's on the right hand cam cover, not on in the fender. I also cannot locate the wiring colors running to the VSV's in the Haynes manual. If you could tell me what colors the VSV's have, maybe that would help. Mine are brown and green, and the connectors cannot be interchanged.

>I looked for that air valve....and couldn't find it. Sorry. I looked around for about 30 minutes with no luck.

I looked longer, much longer, but same result. Look at page 1-13, there's a picture of that *&%$ air valve, on 4-7 a bit of text. And the TPS schematic is there too on 1-13.

Ava.