My 80's running rough....could this be the cause? PICS

[Arya Ebrahimi]

Ok, my '94 is running rough. Almost sounds like it's missing, but I pulled each plug wire individually and it doesn't appear to be based on my observations during that test. I was looking at the EGR valve and noticed there's a port underneath that's not hooked up to anything. There is also a port on the EGR actuator(I think that's what it's called) that is not hooked up(see pics...I'm pointing at the two ports with a screwdriver in the pics).

Could this be causing a sporadic idle?(when I start it in the morning it revs to 1200 until it warms up, then sometimes it idles at 7-800 like it's supposed to, and sometimes it drops down to 3-400)

Thanks for any tips.

Ary

 

[LandCruiserPhil]

Yes there should be a vac hose between them. Install the hose and see if it changes anything.

 

[IdahoDoug]

How about some tips from you to help us, Ary? Did you just buy the truck and it's always been rough? Have you owned it and suddenly yesterday this started after years of smooth running? Did you go offroading and it started? What, what?

DougM

 

[landtoy80]

My 94 reves to 1900 to 2000 rpms when cold.

THe modulator ( the thing with the green cap) should have the hose atached to the bottom of it.

Are you saying there is no hose on the bottom of the modulator?
There should be a hose there.

 

[Scamper]

There's a hose on the bottom of the modulator that's supposed to be connected to that port.

 

[Arya Ebrahimi]

How about some tips from you to help us, Ary? Did you just buy the truck and it's always been rough? Have you owned it and suddenly yesterday this started after years of smooth running? Did you go offroading and it started? What, what?

DougM

Sorry about that Doug. We've owned the truck for about a year now. It's always been a bit quirky in the idle department and has gotten progressively worse over the past year to the point that it now stumbles at traffic lights. I noticed a new sound today as well, that of a rattleing cat, which would explain my recent problem of stalling at a light and significant loss of power underway(pieces of cat blocking exhaust flow). However, that is a new problem and is not what I'm trying to fix at the moment(I will be replacing the cat shortly). I just noticed the fact that the hose was missing today when I took it to my mechanic and he pointed it out to me. I examined the throttle body as well today and when I open the butterfly the backside is coated with brown oily residue, as is the rest of the intake that is visible downstream of the TB. I've heard of cleaning these, but wasn't sure if I need to remove it, or if I can just squirt carb cleaner down the intake(I imagine this would be hard since when I removed the intake hose from the air cleaner to the TB it cut off(I guess the mass airflow sensor is required for operation?)

To be quite honest I only drive this thing once or twice a week and my brother drives it the rest of the time. He is mechanically inept, so I'm trying to help out.

Thanks

Ary

 

[IdahoDoug]

I'd replace the hose(s) and clean the throttle body for starters. Do a search for the cleaning here.

DougM

 

[landtoy80]

Sounds like you need a good tune up and carbon cleaning.

Get some SeaFoam cleaner. Run it in the PCV hose and in the gas tank. You can add it to the oil to if its real bad.
Get a can of BG44K or Toyota FI cleaner and dump it in the gas tank.
You need to remove the intake chamber to clean the carbon out.

Are you sure the cat is plugged? The guards on the cat and exhaust pipe rust and start to make noise as they get old.

 

[landtank]

I don't think that hose being missing would cause a rough idle as it is not a vacuum hose. But I'm not sure why you aren't getting a CE code PO401??? No CE light would definately make me wonder, since that circuit is basically disabled without that hose.

 

[Arya Ebrahimi]

The Check Engine light is not on. I'm not familiar with OBD I vehicles(assuming the 80-series is OBD1), can codes be pulled from the computer like on an OBD II system?

It went in for a dealer tune-up about a month ago and there was absolutely no noticeable difference whatsoever.

Doug, what hoses do you speak of?

Does anyone else have experience with the seafoam product? I've heard both positive and negative things about it, but nothing specifically concerning land cruisers(I live in the Jeep world 95% of the time ;p ).

Thanks

Ary

 

[Rookie2]

I've heard of cleaning these, but wasn't sure if I need to remove it, or if I can just squirt carb cleaner down the intake

IMO, removing the TB is the best way to get it clean (butterfly, blow out ports etc.). Some do it without removing, but it's not that hard to remove. Get an FSM and after the first time you'll be pro.


Rookie2

 

[CruisinGA]

(I live in the Jeep world 95% of the time

Ary

Sucks for you

 

[Arya Ebrahimi]

Sucks for you

yes I know, the Jeep is currently for sale, and when it is sold, I will be building a truggy that will not be any one brand in particular except probably the grill/front clip(that's the plan anyway)

 

[landtank]

The codes for your truck can be pulled witha paper clip. There is info that you can find with the search function of how to do this. Didn't realize you were a 94 so there is a code for the same situation but a different number, sorry

 

[nakman]

I second, or third, maybe fourth the clean the throttle body suggestion. Definitely search around a little, it's not that hard, and there are several informative posts about it. Here's a good place to start.

 

[semlin]

my first comment is that the missing hose may be preventing the EGR temp sensor from generating a check engine code for EGR failure (code 71 on a 94 which is obd I). Those are long nipples and that hose sure doesn't fall off on their own so someone must have taken it off.

check when the turck is cold to see if the heat shields are loose on the exhaust pipes in front of the cat. they very often rattle. It could also be rocks between the cat and the sheild. I very much doubt a bad cat is cuasing you any performance issues, and since you have no way on a 94 to verify the cat is actually bad I think you are crazy to replace the cat until you have eliminated everything else since everything else combined would be cheaper than the cats.

you have a common situation with an 80, that is a messed up EGR system and a bunch of build up in the throttle body. A vacuum leak anywhere in the egr system or a bad egr valve itself could be causing your stall problems. however, if reconnecting the missing hose doesn't fix your idel problem I am not sure because usually egr problems don't cause much in the way of idle symptoms so your idle problem could be in the throttle body, or a vacuum leak elsewhere, including a crack in the big rubber intake bellows.

I would

1. pull the plastic cap off the modulator and see what the filter looks like inside. lots of back stuff means you need a new modulator and prolly new vacuum hoses. not a big deal $ wise.

2. pull all the vacuum hoses between the modulator and both the throttle body and egr valve and look for blockages and corrosion on and in the metal pipes. make sure you have a good vacuum fit and no blockages.

3. check that you have unrestricted air flow from the three vacuum ports on top of the throttle body into the body itself. clear them as necessary. You may need carb cleaner and compressed air to do it, but a stripped twist tie from a loaf of bread can work.

4. Given how bad it sounds, I would remove the throttle body to clean it on the bench (and closely inspect the air bellows while you are about it). The in situ throttle body cleaner will not clean out vacuum ports clogged with carbon. It also won't clean out the port in the intake chamber between the EGR valve and the throttle body which you need to inspect to see if it is blocked. Pulling the throttle body also allows easier access to the rest of the egr system under the intake plenum. you need to check those hoses aren't blocked too.

go to the faqs and read up about the egr system.