yotafool

I have a 98 2.7L Tacoma 4x4 that has some engine trouble. I first bought it back in the summer of 2007 and drove it from Dallas to Kansas City. I was averaging about 24mpg on the highway. For the next few months I would get around 310 miles per tank combined city and highway. My mpg started slowly getting worse and the truck started idling rougher. I did the basics such as changing plugs, wires, cleaning MAF sensor, air filter, seafoam, cleaning throttle body and whatnot.

Recently things have gotten even worse. I am getting about 200 miles per tank mostly highway. I changed my oil back in November and it is very black and needs to be changed already. Plugs also need to be changed again within 10,000 miles because they are very black. Truck backfires, hesitates sometimes when accelerating, idles rough, and occasionally dies at idle. I think I have narrowed it down to EGR, but would a bad or dirty EGR valve have caused all of this?

Is there something else that I am missing or should check? I used to get a check engine light that said I was running rich but it went away about a month ago.

If you think EGR is the problem do I clean it, replace it, or block it off?

I know people have mixed feelings about blocking it off but I have no idea how it affects the 2.7L.

If I replace it do i get one from autozone or from stealer? Autozone sells it for 165, Napa for 165, and OReilly's for 180. I cant find one from Toyota.

If I should clean it how should I go about that? Soaking in seafoam or something similar and scrubbing with small wire brush?

Thanks

Teuf

MM I don't have an answer, but am posting this to get a mail back. I need to check my EGR also.

yotafool

I'm going to take it off today. I've read that I should vacuum test it. How do I go about that?

yotafool

Also I'm going to replace both my o2 sensors. They are both the same part number 234-4162 made by denso for the pre and post cat correct?

Anybody know what the OEM brand and part number is for the EGR valve? Or would I just get a generic one from autozone?

yotafool

Bump. Going to class. When I get back I'll see if i can get it off.

yotafool

Took me too long to gather stuff to clean valve today after class so i'll be doing it tomorrow.

Toyoda22

definately let me know how that goes. I think i need to be cleaning mine too. I read somewhere that to test it you can let the engine idle till its warm then push up on the diapghram of the EGR and if your engine idles down and may stall then your egr is good. let me know any trouble you have and any tips to make this go better. i'll be doing it this weekend with my steering rack bushings

yotafool

if i find something wrong i'll post pics as well

yotafool

i have the egr valve off and it seems to be beyond cleaning. i've soaked it with carb cleaner and scraped as much as i can with little metal picks. is the valve inside supposed to be movable at all by pushing on it? i can not get it to budge, but at the same time i'm not pushing on it enough to damage it. should I just put it back on as is and buy an new one next week, or should i block it off until i buy one next week? if i do block it off should i do it with cutouts from aluminum cans like i've heard others doing?
thanks

yotafool

Here it is just pulled out. Lot of crud in there.







Here is my temporary fix.



Put it all back together and it ran just fine. Seems like its running better than normal but I still think its too soon to tell. I'll be driving it 2 hours away tomorrow on the highway so I guess that will be the real test for it.
I also just changed my plugs, cleaned MAF sensor, cleaned throttle body, cleaned K&N air filter, and changed oil. The only concern that I have is the half fast job that i did making the blocker and the fact that i did not have a fresh gasket to help seal it. I did drive about 15 mins with it on the highway and it seems to be running good. I'll post how the trip this weekend goes with it.

yotafool

truck seems to run a lot better with it blocked off. drove about 400 miles this weekend in all and got around an average of 17-18mpg. not as good as I'd like but a lot better than I was getting.

Toyoda22

I took my EGR valve out this weekend and cleaned it up with some carb cleaner. sprayed a little in the pipe and the intake while i was at it. I used my mouth to create vacuum on the valve and got it moving back and forth smoothly before i put it back in. I changed my spark plugs from the ty bosch +4's i had in it to NGKs and now the truck runs great. no sketchy idling after the truck warms up. i hitnk the plugs had a lot to do with it, but the egr valve was quite dirty and hard to move before i cleaned it. I'm running some fuel system cleaner in it right now. but after that is done, i will figure out my MPG

yotafool

nice. yeah i couldn't get mine to do that. which line did you put a vacuum on to get it to move. i tried the line on the top and couldn't get it to budge. did yours look like mine inside? it was pretty bad and it looked like it was getting bad going into the intake manifold.

Toyoda22

Mine looked about the same as yours. i wanted to really get in there and clean that whole pipe but i didnt have the time. i had some degreaser i cleaned the valve with and then hit it with the carb cleaner and let it sit opening the valve and closing it a bunch of time. I just used my mouth to get it moving. its the top little metal tube that comes out the top of the egr. I could tell it was opening and closing because it would leak down the cleaner when i opened it. you can tell when its snapping shut bc it kind of clicks and you can feel a spring vibration as it shuts.

yotafool

truck is running like crap again. i have no idea lol. i may buy a new egr and see if that helps then it will go to a mechanic to be looked at i guess.