22mr2

you might want to pop off the air inlet hose off the throttle body, open the throttle and look behind it for a bunch of black goo. If the idle air control valve gets all gooped up with that stuff, that might be causing it to bind.

Bill54880

Here is the intake or throtlebody. What should I do now?

22mr2

Get a few cans of throttle body cleaner, spray, soak, scrub with a tooth brush or a good brass bristle brush. CHeapy brushes will break off the bristles and send them down for a intake ride. All the ones I have had that were that dirty, I take off, strip the electronics off and soak in carb cleaner. Take a look on the site to see who has any good tips for doing it on the truck

Bill54880

What caused this or is this just normal build up for 168,000 miles? If something is bad I want to change it so this doesn't keep happening. Is it safe to spay tb cleaner in while its running and/or when its off and cold and just let the engine run all this black crap and tb cleaner through the engine?

22mr2

Totally normal, especially with higher mile engines. The throttle body has a hose that sucks air right from the valve cover, which when you start to get an engine up there in miles has alot of blowby past the rings, but even newer engines will do this to some extent. Toyota 5sfe motors are notorious for this. You can try to do it running but it most likely wont run, because the afm cant get a reading when its unhooked. It wont hurt anything, but it will make it hard to start and it will run rough for the first minute, till it works all the cleaner out. Check out a product called sea foam too, I dont like it but alot of people rave about it. The lil ports in the throttle body should all be sprayed out too. The one on the bottom left is to the idle air valve, the upper left is to the idle screw and the one on the right is the one that goes to the valve cover. Disconnect the hose to the valve cover and spray into the throttle body

Bill54880

Since I have to go to work later I just sprayed tb cleaner in there with the engine off and used a long brush to clean the throtle plate and around it. I also just sprayed some past it in general in hopes it would make a difference some where. I also sprayed down the IAC hole that you talked about. I then started it up and of coarse it started hard but then idled fine with a much stronger idle. I then pulled a vacuum line and squerted in some more and then drove it around. Wow! Just that little bit that I cleaned has made a big difference in the power! I'm not sure if we've solved the problems completely yet but I do know that this has and will make a hell of a difference once I take it all apart and clean it up proper. Thanks! I also want to mention that I have seafoamed it through a vacuum line a couple of months ago and as you can see it didn't do jack to clean it out so I'd say forget that stuff and go with the cheap throtlebody cleaner spray that I bought for half as much. Any other thoughts? I'll let you know in the next couple of days if it's better or worse on that big hill I keep talking about.

Bill54880

Question, so with the intake all clogged up like it is/was and the fact that the injectors are seperate from the air intake system that means I was running rich because it just couldn't get enough air in at the rate it thought it was which was causing a loss of power because of the rich mixture?

22mr2

IM not sure if the deposits cause a rich condition or not. I think alot of it has to do with overall efficiency of the air intake stream to the head. Its such a rough surface that I think it causes alot of turbulance and makes it more difficult for the airstream to flow into each port on the intake equally. Id guess its that imbalance between cylinders that makes the o2 throw the mixture toward the rich side but it is just a guess!

Bill54880

I decided to take apart the intake and clean it the best I could. The real reason for doing it was that I wanted to see how clogged the intake was. The good news is that the intake wasn't clogged just very dirty. I also found what appears to be an intake leak. I also found that the vacuum lines where almost completely clogged so I sprayed them down and made sure they are free flowing.

I cleaned it out with a can of spray and put it all back together and now I'm warming up, as I'm working outside in Wisconsin at about 40F. I'll fire it up shortly and repost with the results.

Here is a pic of the engine with the throtlebody off as I started my cleaning.

Here is a pic of the inside of the intake. Notice the clean spot below the cold injecter, leaking maybe?

Here is a pic of the gaskets where the upper intake meets the lower. Leak?

22mr2

The clean spot inside the back of the intake is from the cold start injector, totally normal, fuel keeps that spot and the 2 back runners alot cleaner than the rest. Yeah, looks like there was a leak on the back runners, a new gasket will fix that real quick. Cold here 2- hate winter already

Bill54880

The more I drive it the better it feels. I still think I have a slight problem some where because of the occational loss of throtle response, maybe just a new tps or something, but over all I'm way happier now that I cleaned it because I have so much more low end power that I don't have to ram the rpms up to 4 grand all the time to get up to speed.

22mr2

whats the symtoms of the loss of throttle response? Just when cold, just when hot, sputtering?

Bill54880

Once it's warmed up it will sometimes just get weaker the further I push the pedal down past 1/4th throtle rather than get stronger. It doesn't back off the throtle as if there is a "dead spot" in the tps it just seems to get weaker rather than stonger like the mix is getting thrown off by pushing the pedal. As quick as it starts it stops and goes away so it's hard to get a real good chance to play with it and see what the problem is. Usually I flutter the pedal and it goes away. So in short, when this is happening the most power is at quarter throtle not full throtle as one might expect.

Ezrider_92356

i would unplug the tps and see if it runs better

22mr2

How often does it happen? You might want to do a few quick checks. Pull the hose off the egr and suck on the hose to see if the egr is stuck. Doesnt taste very good, but if the egr is ok, youll hear it move. X2 on the tps, it wont hurt anything to unplug it and the worst it will do is give you a high idle.

Bill54880

What do you mean by "X2" the tps?

22mr2

agreeing with ezrider about unplugging the tps, if you unplug it and you still have the same problem, its not in the tps circuit.

Bill54880

Which vacuum line? The one on the top?

22mr2

yes, the hose on top of the diaphram.

Bill54880

So if it's the egr, what do I do? Can I clean it or something or just buy a new one?