seafarinman

My 3.0 is running rich- at least that is what the error codes are saying. I noticed a big drop in gas mileage- 240 miles per tank to 140 miles per tank. I keep getting the CEL when I am idling. I keep pulling the EFI fuse and that clears it, but it will come back when I am idling like at a stoplight or something, but not when I first start it up in the morning. I heard somewhere that the injectors like to start dribbling fuel when they are old and worn out. I imagine that could cause a rich condition. Anyone know how much it will cost to get the injectors rebuilt or replaced? I had already replaced both O2 sensors for $120 each! I am out at sea in Southeast Asia right now, so I can't get it fixed until we get back home again. Thanks in advance!

GTE4runner

jump the test connector in the engine bay so you can see which code the ecu is throwing. My guess is that its a bad oxygen sensor.

AgRunner06

O2 sensor

95_4X4Runner

First, pull the codes by jumping E1 and Te1 in the test connector.

I would suspect an air leak. Say the engine thinks it's getting 100 cu/ft of air, but actually only 75 is making it through the throttle body. It would definetly run rich.

With a 10+ year old vehicle, I'd recommend checking out all of the hoses to the throttle body for dry rot/cracking, and a quick check of the vacuum lines.

AgRunner06

If it had an air leak it would cause a lean condition because the amount of air going into the engine is greater than what went through the AFM.

BTW if you read his post, he's already pulled the codes.

My bad, he already replaced the O2 sensors...I'm guessing this is a Cali vehicle since there is more than one. The only other things that I can think of would be a problem with the AFM or CSI. How well does it run? Is there any missing, shaking?

The CSI is easy to check. Just undo the two 10mm(I think) nuts and it pulls right out of the intake plenum. These do tend to leak and usually cause problems with cold starting. However I think mine became stuck open once and my truck would barely run. So if yours is leaking enough fuel, it could make it run rich. It takes a whole 5 minutes to check so you might as well.

If you pay someone to do the labor on an injector rebuild, you will be looking at about $500. Otherwise Cruzin Perfomance will do them for $12 a piece. When I sent mine in there was a 6 day turn around time. RC Engineering also does them but they run $20 a piece over there. I don't think that is the problem unless you are having other fuel related issues.

Also it couldn't hurt to make sure your connections to the O2 sensors are good. I wouldn't think that would be the problem but you never know. Sometimes its the easy stuff that you overlook only to find out that you didn't need to spend any money to fix your problem.

Good Luck

:bounce2:

seafarinman

Thanks for all the replies. I remember also that the exhaust smells almost like pure gasoline as well. I have been avoiding it, but I guess that the truck needs to visit the dealer or some good import shop.

95_4X4Runner

I thought I may have been confused, an intake leak with boost would run rich. Regardless, good luck, and let us know what you find.

What about a leaking cold start injector?

silvertaco

Check your compression. My father had the same problem, even had the same drop in miles per tank. Ended up being a burnt exhaust valve on #4

seafarinman

So how much will it cost me to get that fixed? I have never taken apart the internals of my 3.0, so I am kinda worried about that. I guess that it would involve pulling off the heads. My engine has almost 200K miles on it, and it is overdue for having the timing belt replaced anyway. I guess that a rebuild or another import engine would be my best bet at this time. Thanks for the ideas.

TRunner

The heads should cost under $300 for a full valve job. I had an exhaust valve burn up as well. You will want to fix it as fast as possible or or cat will go bad, but I would replace it after you fix the running rich bit anyways, because it causes your cat to get clogged. You can get a universal one on ebay for about $56 shipped. I have a link in another thread somewhere. If you haven't doen the timing belt by now I would get that done! Here is what I would suggest:

1. Check all your spark plugs for oil on them or in case one or more is not firing.

2. Do a compression test. If you find that you have low compression in one or more pistons then add a little oil to that piston and try again. If you have the same results, you probably need a valve job. If it corrects the problem then you have bad rings. Have a local machine shop do that work and not the dealer. You also have the option at this time to get some oversized valves put in. It wont cost much more at this time and it makes a good jump in power.

3. Replace your timing belt!!!

4. Get your injectors cleaned and flow tested. I used this guy as his prices were more then fair ($12 per injector) and he replaces all gaskets, screens, etc for free. Plus he gives you full read outs and all your old crap bag. Very professional!

At almost 200,000 miles I would do all these things with the exception of valves and rings if not needed. Your O2 sensor might be a problem, but I got mine out and sprayed it with brake cleaner and stuck it back in. Now it workls fine. I don't suggest this, but it worked for me.

Also I am currently running rich because of a cold start enrichment injector that stays on all the time. I don't notice too much gas smell, but it does idle very high and is going through gas. I have to fix that this weekend, but I doubt that is your total current problem, just another heads up after you finish the other things.

If you have any quetsions, feel free to ask and good luck!

seafarinman

Ted,
thanks for the information. I was looking for a rebuilt engine on the internet and was quoted $1995 shipped including a $500 refundable core charge so that means that the engine is $1495. I might consider keeping the old 3.0 to rebuild and save for my Samurai that I am planning on getting when I get back stateside.

AgRunner06

So has a compression check been done yet? That will determine if you really have a burnt valve. There's no sense in jumping the gun and spending more money than you need to unless you want to replace your motor anyways.