Hitoyota84

Hi.......
I have a 93 Fourrunner with 235,000 miles on it. It started running rough a month or two ago so I changed the cap, rotor and spark plugs. I also replaced the air intake tube because it was cracked. It isnt any better after doing this. Would possibly changing the wires help? I was trying to avoid that as they cost about 100 bucks at the dealer. The smell coming out of the exhaust is really rich but its not smoking. Any input would be greatly appreciated.....

swaycleveland

hi brunswick north ridgeville here ! what do you mean by running rough? idle? driving under load? if you can discribe the symtoms better we could help
did you check your timing? when was the timing belt last changed? and one of the most important things is VACUUM lines. make sure they are all pulled in. spray some starting fluid around all the vac lines to check for leaks

Hitoyota84

Hi. It runs pretty rough under a load. when its in neutral or park it seems a little better.

swaycleveland

like death cougar said in your other thread i think there is un metered air coming into the engine. try spraying some strating fluid on your vac lines and see if the engine surges or dies. all the vac line!!!!!!! front back side of engine ! one line unplugged can make our motor run horribly
did you check to see if you put the wires back on the right plug?

Hitoyota84

I havent replaced the wires for new ones. someone did mention something about an 02 sensor maybe going bad. but I figured the check engine light would come on for that.

swaycleveland

the CEL might not come on if the o2 sensor is bad
are you sure when you replaced the plugs that you put the wires back on the right plug?
i really dont think its the o2
check vac lines
check to make sure wires are going to correct plug
check egr valve
check timing
do you have the service manual ?
if not you do NOW
http://www.ncttora.com/fsm/1993/index.html

Hitoyota84

Thank you so much. I didnt put the wires on myself, my friend did. He probably did because it is running the same as it was before we pulled the old spark plugs out.

Hitoyota84

The spark plug wires were put back on correctly. There are no vacuum leakes, that I can hear. I bought some new wires so we will see if that helps. The dealership said they can put it on a dx tester for 87.00 bucks. Maybe that will tell me where the problem is... What is strange is the check engine light has never come on.

Andy_Structable

you may have got this by now, but if not, i might be able to help. did it suddenly get rough, or did it ease into it? were you driving at the time or did it just start one morning? once you check spark and air, try fuel. it is less likely if it started suddenly, but have you replaced the fuel filter recently? those are cheap and easy to replace, and even if it isn't the problem, it never hurts to have new fuel filter, especially if you haven't done it in 70k miles. remember, on a 93 you can order your own engine diagnostic tester for as much as the dealership will charge you to plug into theirs. amazon.com has a simple one for $25. but it probably won't tell you anything anyways because if there were a trouble code, the light should normally be on, although not always.

something to try with the vacuum leak. make one, and see what happens. the easiest way to do this is to start at the brake booster (big round thing on the firewall) and follow the big rubber hose back to the intake manifold. remove the hose from the manifold and you have created a vacuum leak. removing the hose should make the engine run worse. if it doesn't, you probably have a massive vacuum leak somewhere else. now, put your finger over the nipple that the hose came off of. it should suck your finger up against the opening. this is a simple way to check the vacuum. if you can't tell the difference between plugging the hole with your finger and leaving it open, either in how the engine runs or in the suction you feel on your finger, it means a bad vacuum leak. if you feel excessive suction, it means there is an obstruction in the air intake.

my buddy used to store oil rags by stuffing them into a crack under the hood. one day, it sucked a rag into the air intake and plugged the line. the truck basically ran just as you described. we noticed the power brakes were very touchy, meaning too much vacuum, meaning obstructed lines.

i suspect the diagnostics you want to run are a vacuum test, fuel pressure test, and maybe even compression (if it is a problem in the guts of the engine you want to know about it before you pour a bunch of money into other stuff) chances are, the fuel injection computer has little to tell you. all of these testers can be bought at a parts store for less than you pay a dealership to run the test. amazon also has a combination fuel pressure tester/vacuum gauge for the low, low price of $12. the dealer won't open the hood for that.

get your manual, get the $12 gauge, and follow the instructions. then you will have some real info to go on. also, remove one of the new spark plugs and see if it has fouled up. a poor running engine will foul spark plugs quickly. if they look like there's crud on them, is it dark, or light? while your at it, with the engine running, remove and replace the plug wires one by one. each removed wire should make the engine run worse. if you find a wire that makes no difference whether it is connected or not you know a cylinder isn't firing.

maybe that gives you some ideas, then again, maybe you've solved the problem by now.

Hitoyota84

Wow thank you so much, that is alot of useful information. If I remember correctly, it started suddenly. I dont think it was minor and then got worse.

I will definitely try those tips, no I havent taken it in yet. And so far no check engine light has come on. No wonder they call them idiot lights LOL......

Thanks again.
I will keep an update if I get anywhere, in case someone else has the same problem.

Hitoyota84

Update.... I took the truck into a auto repair shop. It took them a day and a half to figure out my number 1 and 3 pistons have a compression reading of about 40. I guess normal is around 150. Not sure what I can do about it at this point.
They told me the engine needs to be replaced, duh..... for about 5 grand I can get one. I only paid 3700 for the truck 3 years ago..... Is this something that is major to fix.... It has a tendancy to burn oil somewhere and it gets low and I always try and check it but somtimes it ran a quart low, could this have been what caused the damage.

Innervision

I would find a new shop if it took them a day and a half to do a compression check. Also 5 grand is a bit expensive for a new engine. Is it a V6? Low compression could be a head gasket issue which the V6 is famous for having. Also since its 1 and 3 cyl I would suspect the HG is where the problem lies. Have you noticed the coolant being low? This can be fixed at a shop for under 2K.

Team420

x2 on the h/g... usually when 2 cyl side by side have low compression #'s, its an indication that you have h/g failure... not always... but usually. Def check your coolant. also...you said the exhaust has a rich smell...is it kinda sweet smelling, or like roten eggs, or unburnt fuel? Sweet smell would be coolant burning....another indicator of h/g failure.

Hitoyota84

we replaced the head gasket about a year ago, maybe a little longer. when that went it was running fine, then all of a sudden i started it up one day and it was pooring smoke out of the tailpipe. So we fixed it, luckily ourselves, so it only costed me about 200 in parts... They seemed like the almost didnt want to be bothered by it since it was so old and high miles, but I guess they had to come up with some answer, so it makes me wonder if they are even right. I told them all we did before I took it there, and they still rechecked that stuff which wasted a good part of the time. Then the next morning after about 3 hours they call me and tell me they did the compression check and 1 and 3 are very low. I am not really sure about the exhaust smell, only that is is not normal, smells kind of rich... I wonder if I burnt the valves..

Team420

You did h/g's for $200??? Did u reuse the head bolts? Those are known to stretch, also what kinda gaskets did u get? I been looking around and so far, a complete top end gasket set is over $200 by itself, then u got the bolts to buy($8 each I think), and whenever you do h/g's you should always send the heads out to be re-surfaced, and checked for cracks. I'm not saying you didnt do it right...cuz I dont know what you did... but if not done properly... it will continue to eat h/g's untill it becomes terminal.... my $.02

Hitoyota84

sorry, it was more, close to 500 bucks, bought timing belt, gasket set, spark plugs. oil. we did not send the head out, it was all cleaned up and it didnt ever over heat. It has ran great since then, over a year now with now problems. whats weird is when I bought it the engine compartment was so clean you can eat off of it, and now it has a oil film all over it and whenever I put the oil dip stick in and I check it is always a half an inch pushed out. Its like oil and fumes are comimg out of the dip stick or something.

swaycleveland

have you even tried the vac lines yet!!!! did it run better worse or the same if you remove a line as the other post said. 5000 for a motor hahahahahahahahhahha
i swear if i have to take a trip to brunstukey ......
ill be you and whoever is working on it a sixpack that
A your motor aint shot
B you have a vac leak somewhere
C you didnt change the tensioner when you did the timing belt and it jumped

seriously if you want ill take a peek at it sometime next week
let me know

Hitoyota84

Hi, the coolant level is fine, never had a problem with that. I do not believe its the head gasket this time. I will either have to find another motor for it or sell it while it still runs.

Hitoyota84

They were a bunch of yahoos from the start. I wonder if they even did a compression check on it...... I feel like they said screw it lets just make something up that goes along with the symptoms since she isnt having us fix it anyways....
I told them off the bat, I just need to know what is wrong, and I can get it fixed. I dont think they liked that.

Ya the guy told me 5 grand for a motor with a 100,000 mile warrantly. I love my truck but I would never invest 5 grand for a motor. I hopefully can find one for it that someone is selling but want to hear it run in the truck. If you hear of any let me know.
P.s. we did check for all vacuum leaks and found none...The timing belt was replaced when the H.G. was about a year and a half ago..... Whats odd I think is when it is in park it seems to run very well, but as soon as I put it in drive that is when it starts. Also when I accelerate it runs smooth, but when I let off the gas it shakes like the tires are unbalanced but they are not.

swaycleveland

the offer stands if you want me to take a peek i will. im sure most people on here would. i dont think there is any reason to sell it or spend thousands
seriously the 3.0 motor does have its quirks but most can be fixed by a 14 year old ( and by that i mean
you just have to know what to look for )

atleast have someone who knows yotas look before you give up on your baby