70elcoss

Just finished a rebuild on my 3.0 and it just about runs amazing! Only problem is that it has a low idle and sometimes even shuts off. The throttle body was leAking so I thought that was it, nope it helped slightly but not much.

There's only 2 things that I can think ok.... My hard fuel line under the intake plenum has a little kink in it. I don't think this is it because it runs good as soon as it starts rolling! It's just the idle.

Also, when I did the rebuild I broke the pcv hose so I replaced it with a hose I had laying around but it was slightly thicker so when it made the bend it also kinked probably restricting airflow... I'm thinking this might be it?

I tried to adjust it by backing out the idle screw but when backed out all the way, it only raised the idle to about 550 rpms and is still a little rough. Could it just be the ECU having a hard time re-programing? I'm totally lost on what to do, I don't see any vacuum leaks or anything.

70elcoss

Also it has about 65 miles on the motor since the rebuild and it still has black smoke coming out of the exhaust even when warmed up. Mpg is also terrible so far lol drove about 40 miles today and used almost half a tank.

ksti

The first thing I would check is vacumn lines

pholife

and coolant temp sensor; clear coolant lines of the bottom throttle body....

70elcoss

Right now I only have water in the cooling system. Would that have any affect?

norcal98

iTrader: (3)

I cant imagine only having water effecting the idle, though obviously wouldnt leave it with just water. You doing a flush?

Did you check timing after rebuild?

Adjust TPS?

70elcoss

I plan on adding coolant soon, just added Only water for the Intial start up. Yes timing is at 10* btdc. How would I go about adjusting the tps?

norcal98

iTrader: (3)

You can do a search here if you like or try this link to see if there is anything there to help you.

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml


Make sure you use the toyota red for your coolant if you werent already planning on it. Its more money, but worth every penny. I've always used it, but wasnt a real believer until I looked at my wifes motor with well over 300k plus and clean as we whistle inside vs a motor with half the miles but full of rust and scale from using the green(dont know how often they changed it, but doesnt change my opinion).

70elcoss

Ok well I think there's hope for me lol I checked the timing In the morning and it was really high! Past 15* I believe so I lowered it to 12 * and it seemed to stablize the idle. It is still low because I was messing with the idle screw yesterday and left it screwed in almost all the way. When I gethome I'm going to mess with that and hope it fixes it.

norcal98

iTrader: (3)

Hope so too. Hard to know for sure what a problem is without being there, but it was guess based on what I think you were saying. Using the eye of the wombat, the bolt on the dist should be roughly in the center. Obviously need a time light and get that thing at 10 btdc, but that a rough guess. After you get it done with a time light, then mess with idle screw and see if you can get it running right where you like it (800-1000). Hope that fixes it and holds time, otherwise we've got other issues.

Dont forget to use the jumper wire.......

70elcoss

Well havent fixed the issue yet and it's getting irritating lol I might have a solution....

When I took the motor out I stripped an exhaust bolt so I had to cut the downpipe from the manifold before the o2 sensor... I don't weld so when I put it back in I just used a band clamp to hold it together in place for the initial break in.... If it's leaking before the o2 sensor will it cause this? I'm expirencing the rough idle, poor gas mileage and black smoke out of my tail pipe when warm and cold.

I don't hear an exhaust leak but I'm pretty sure it's still leaking regardless because I think the clamps I used was for plumbing or something haha idk it was the only thing I had laying around the house

70elcoss

anyone have anything to say about my exhaust leak affecting the o2 sensor idea?

4runrjunkie

I hate to bring an old thread back to life but this describes exactly what i am dealing with right now. Does anyone know if an exhaust leak before the o2 will cause the low idle issues? Any possibly effect gas mileage?

tyson8851

it could be the intake hose to the throttle body, they tend to crack and suck air wich causes the o2 to be lean and the idle to be low, then the ecu over compensates and runs rich, giving you black smoke... Something to check out anyway, usually cracked on the inside bend at the bottom of the tube.