wittekl

I have a 1995 4runner sr5 3.0 5spd. ever since i have got the car my check engine light has been on. its code 71 which is my egr valve. i was gettting 16-17 mpg while wheeling it 3 times a week. now im getting about 14 and i havent wheeled it for 2 months. i sucked water into my motor about 2 months ago and i did everything by the books. runs fine i put new plugs , wires and changed all fluids multiple times. but lately it has started to run rich. black smoke when it starts, just alittle very little. and ive been getting the 14 mpg mostly city alittle highway. it has 135,000 miles on it. i was just wondering what u guys would think. any input would be nice. its also 31" bfg's and stock gearing. my exhaust is just a cherry bomb but with all stock piping. dist cap, rotor button , o2 sensor, egr valve what can i do to get better gas mileage.

Bob_98SR5

seems to me you already know what the answer could be. the gas mileage problem is just a symptom of what happened to your engine. its a little unclear if you fixed the egr valve problem. did you fix it? also, did you check to see if your MAF sensor is gunked up by mud/debris when you went swimming?

search "2nd gen EGR valve" and see what comes up. Also try searching "2nd gen MAF" and also see what comes up as well.

...does a 2nd gen even have a MAF? help me out, 2nd gen guys...hehe.

bob

surf4runner

time for a prius?
time for seafoam?

wittekl

no i never fixed the egr problem i dont believe i have a maf i have a flapper that i know off. i talked to a mechanic tonight and he thought a vacuum line or either the egr. but the egr valve is so expensive. how do u use seafoam, how much and would it help?

wittekl

should i run 93 octane in it?

erik

I'm heavily into DSMs (diamond Star Motors) I'm now interested in modifying my 4Runner. For best of multi use for 4x4, fuel, & performance.
In my experiences with DSMs. You can block off the egr off the intake manifold with no adverse affects to prevent the exhaust gas to reticulate back into the intake. This allows for a cleaner burn and also a cooler air intake temp slightly. It also prevents me from getting anymore soot in the intake tract. So for this purpose we remove the valve and replace it with a block off plate. I'm not sure if the 4Runners can allow this if there's a sensor that may throw a error code and thereby cause the ecu to burn differently and screw things up again? But I'd look into that. IF you can block it off with no adverse affects, please let us know here.
Also, it's very likely that if you ingest any of the littlest bit of crap into the air canister, then your MAS either has to be cleaned or replaced. These are temperamental. I've cleaned my MAS probe (the lil cap in the middle of the intake stream) with break parts cleaner. Then let it dry completely before operation. This will help. My ecu has thrown codes before and this remedied it.
thirdly. Does anyone know of a better manual than the Chilton's or Hanes manuals? They really suck and it's hard to make heads or tails about what I'm doing to the car. thx.
ew

kyle_22r

a properly working EGR will get you better gas mileage. why? because it's displacing air/fuel mixture in the cylinders with a small amount of exhaust gas. it's only supposed to kick on when cruising or when there isn't a demand for a lot of power.

that said, i have it blocked in my '79 truck, but it gets about 14mpg from its heavily modified engine.

erik

I suppose one could get some benefits out of the EGR if you have unspent fuel. Then it would go back into the intake to burn it. But theoretically, I disagree with this statement. (unless proven otherwise) Correct me if I'm wrong here.
For one. If you needed to displace your air/fuel mixture that is the job of the intake chamber (manifold) and injector pattern. And the amount is controlled by the throttle body and the ECU in a general point of view.
But the EGR is Exhaust Gas Recirculation. If you have a properly tuned engine, you will have a cleaner burn, as well as better fuel efficiency.
Hear me out if you will.
In your exhaust you have HCs (hydrocarbons) and other byproducts of the combustion. All that your engine needs is the correct fuel and oxygen in the right amounts at the right time to make a clean/efficient burn.
Our trucks (esp. the 2 & 3rd gens) are so latent with emissions crap to minimize what comes out of our tail pipe, that it is almost redundant. (could be)
Well, it could be, in fact, if we all had an ECU that could tune for closer tolerances. If there were a perfect world answer, the ecu could tune closer to the lean side. (stoichometric point)(splg?).
So what if someone were to take out the EGR? That may not resolve a problem, but may still help. If there was an ECU controller that would allow us to manually make a cleaner burn with our preferences. Such as when you are tuning for a performance auto. You would try to flirt with the leanest condition without burning the engine up. Thereby getting the cleanest burn. Thereby reducing some of the emissions (especially the HCs) out the tail pipe. See it's turn-key.
ew

kyle_22r

actually the leanest condition isn't always the cleanest. the hotter the combustion chamber gets, the more NOx(i think) it produces. the EGR cools down the chamber somewhat. the engine is actually tuned to run with the exhaust gas circulating into the intake, which in turn enables it to inject less fuel during a light load scenario.

rocket

iTrader: (1)

Their expensive but worth the money.
Heres a link with the phone number so you can order one:
https://www.yotatech.com/forums/show...highlight=fsms

btw, Welcome to the forum. Good to see another local CO guy and one that spells his name correctly...with a "k" and not a "c"

ThomasJ

Dont go and just buy an EGR and put it on. It may not fix it. There are alot of parts that will cause a code 71. The code 71 is present because the temp sensor in your EGR valve housing is reading low. This could be caused by a, bad sensor itself, clogged EGR tubing, broken or loose vacum lines, bad EGR VSV, EGR vacum modulator, or the vacum lines could be simply hooked up wrong. Ask me how I know

A quick test for your EGR is to pull the vacum line off the top and replace it with a longer one temporarily. Then apply vacum (or just suck on it) to the EGR with the engine running at full operating temp. The engine should stall or stumble. If you can not get it to do this then the EGR probably is bad or clogged. If it stumbles, your EGR is not bad and your tubing is not clogged. Try this test and if it the EGR checks out good you dont have to waste your money. I had a code 71 on my 4Runner when i got it so ive been through all the testing of the complete EGR system. There are alot of other people here who are familiar with the sytem also so im sure you can get it fugured out without gambling with your money. Toyota parts are not cheap. Let us know how it goes.

You do not have a MAF. You have a VAM (vane airflow meter). It can cause the rich condition you are describing. But there are ways to test that also.

ThomasJ

I am into 2.3L turbo fords and we also always remove the EGR for two reasons. One, to keep the intake cooler. Two, to keep the intake, intake valves, and intake ports clean. On the 4 Runner you could replace the EGR temp sensor with a resistor of the proper resistance to eliminate the code 71 you would normally get if you removed the EGR. If you dont have emissions testing i dont see any problem in doing this. And it would be easy to put back on if you ever had to start doing the testing.

Van91DSM

Yep. EGR helps to reduce NOx and cylinder temps while cruising.

Fancy seeing you here ew. I recently picked up a project '88 4x4 pu that is now running very well.

brandontrek

is it just me or are there a lot of dsm guys floating round here lately..

erik

Noice!
We can't let well enough alone, can we? What a horrible disease this is. If I had a few million dollars, I'd have many cars. But then they all would be modded as well. .. It never ends.

...recient mod to the 4Runner. A basic remote start system. Hoot!
Nice to see you two here!
__ I just like these faces. They're a trip. :walk: