94 Yota 4Rrunner

ok i have a 94 4Runner with the 3.0 3VZ-E, and it seems to be running fine and all, no check engine light is on or anything,but under acceleration, around 2500-4000 RPM you start to hear that low end ping when the timing is not set right. so i borrowed a timing light, jumped the 2 terminals te1 and e1 like it says to and i get a reading of something way over 10 degrees before TDC, funny thing is, when that test connector is put in place, there seems to be no sound change in the engine, almost as if its not seeing the test jumper. when i try to set it at 10 the engine idles very rough no throttle response, and im at the max travel of the distributor. so something is not right. HELP PLEASE!!!

gas milage sucks too lol

Marc

To make sure you have it jumpered correctly the Check Engine light should be flashing.

thook

Well, with the test jumper in place....on the te1 and e1 terminals.....and the key on, verify that the CEL is flashing. That way you'll know if the ECU is registering and you have good contact at the jumper.

If all that's good, then it may be an issue with the throttle sensor. On the other hand, even with a brand new TPS set correctly, I've never noticed much of a change in RPM on my '92 3vze when I jump the diagnostic terminals. I mean, there is a minute change, but fairly unnoticeable. (It's a lot more apparent on my 22re!) So, I wouldn't worry about that too much. What you should notice more so, with the timing light flashing on, is that the timing mark changes it's position. With the jumper in, the mark should retard to base timing....10*btdc. With the jumper out, it should advance. Not really sure to what, though. You should also notice if the timing mark remains stationary at 10*btdc and not bouncing around.

That being said, you're timing may have been fine from the start, and when you started fooling with it, it is now retarded too much. So, make sure of what I said in the first paragraph and try and reset the timing so that the engine is running smoother again. And, also check your tachometer. As long as you haven't begun to fool with the idle speed set screw, it should idle at 850-900rpm. Keep in mind, do ALL of this with the engine at operating temperature. If you neglected that during your first attempts, it may be part of your troubles.

If you just can't get the timing right, then start looking the throttle sensor. And, then you can also address the ping, if that's what you are hearing. Could be the TPS or something else.

About your mileage, what was it before you started messing with things, did the mileage suck then or after your messing, and what exactly were your mpg's, anyway.....before and after?

thook

Hehe.....beat me to it.

94 Yota 4Rrunner

well when i do put the test jumper on the check engine light does flash continously and so does the O/D off light. so i know that i have a good connection.

so that answers ur questoin Marc

94 Yota 4Rrunner

well the only reason i thought there should be a difference in the sound of the engine was because i used to have an older Mazda B2600 and when u would ground the test pin the idle would drop and the timing mark be set to base. so thats y i figured i should notice a rpm change, mind u that was a 4 banger and this is a V6 so the change would be less noticable, but with the pin grounded or ungrounded the timing mark stays the same. when i first bought the truck it had sat for 6 months in a parking lot, so to ease the process for the emmission test i took a can of carb and throttle body cleaner and cleaned the entire throttle body out and i also sprayed inside the airflow meter box to clean it out as well. now after i did all of this the idle was very high around 1500 RPM. so to compensate for that i screwed the idle screw in to lower it. and it seemed to run much better. but i had an issue with it when i would heat up during start up. as it would run it would surge a bit, drop in rpm the raise. i fixed that problem tho, i had a coolant air pocket. so with that fixed it hasnt done that since, however it seems to be idling high still even with the engine at full temp, and then as i drive it, the idle would drop off. now i never knew what i was getting for millage before i screwed around with it because i didnt have it on the road yet. but with a full tank i was only getting maybe 300KM to a full tank which is pretty lousy i must say.

i did take the TPS off of it beause i did suspect it as well, i had read threads about ppl that had the same problem. so i took it off and did the tests on it, and it seemed fishy, but yet i dont have the check engine light come on in the truck. so its sorta weird.

dont know if i have made my problems any worse by screwing with the throttle body, but im hoping someone can lead me in the right path as to what i did wrong and how to go about fixing it. thanks

thook

The CEL doesn't come on necessarily just because the TPS is bad.....if it's bad. The CEL comes on if it detects an error in the signal from the TPS.....ie. the IDL signal drops out period = no voltage. But, as another example, the VTA circuit (throttle angle) could be worn on the track, have a drop in resistance, yet still maintaining a signal, but the ECU doesn't equate that to an error. It's still getting information and doesn't know that the voltage signal doesn't match to the physical position of the throttle plate. Did that make sense?

Anyway, what do you mean "it seemed fishy"? I'm going to assume you don't have any record of what your findings were when you tested it.....I wouldn't either. But, you might want to test it again and post the results.

94 Yota 4Rrunner

well by fishy i mean that when i went to test it i found a site that had info on how to test TPS for 3vze and 22re and when i was testing it, i wasnt even gettin a reading on it at all, even with the terminals they said to use, however if i reversed the sensor and did it so that the bottome was the top and the top was the bottom, well then i actually got some readings, but they were still off and not exactly what i should be getting. i cant remember what my readings were but i know i wasnt getting anywhre close to the specs. i was way out in left field

thook

Assuming you have the correct TPS for your vehicle (the original factory unit, right?), it sounds like on your first attempt you were just confused and then not doing something right. Possibly even had your meter on the wrong settings.

For now, let's see if we can get you somewhere bypassing the use of the meter.

Take the TPS a tad loose just enough to move it. With the motor running at operating temps, turn the TPS from full clockwise (as you're on the driver's side at the fender) and move it counter clockwise just until the RPM drops. Then, snug down the top screw. If you find where the rpm drops, that is the IDL setting. This where the ECU needs to register a signal from the TPS allowing you to be able to set the timing. Try the jumper and check the timing again at this point. If the jumper still doesn't change the rpm or timing marker, test the TPS again with the meter.

IF you don't get a change in rpm while turning the TPS, it's just time for a new TPS. I'm hoping you haven't damaged the internal circuitry with the carb cleaner.

94 Yota 4Rrunner

well u see thats what i was afraid of that i got carb cleaner into it, but i dont know how i could hve seeing as how the TPS is on the back side and i was only spraying the inside of the throttle body. how ever i have heard of that tho, the carb cleaner messing with the circuits, i will give ur test a try in a lil bit and see where i get with it, just to clerify, again which way does the sensor have to move to get to the IDL setting, turning so the harness goes up or down?

thook

Up.......away from the motor, if you start from all the way towards the motor......down.

94 Yota 4Rrunner

hey i did exactly what u said and it worked out perfectly, the sensor was wayyyy out of adjustment, couple ticks in the right direction and boom idle came right down, and the timing set right to base, perfectly too, i had to adjust it mind u, i was off about 6* lol, so thank u very much for the help, now i should hopefully gt better gas milliage, i found the sweet spot by using the timing light, and just watched the timing mark, and as soon as it hit the spot where it dropped off i tightened it down, just went a tich past tho to make sure i was at idle every time, cause i think my dash pot might be worn out so sometimes the throttle plate doesnt always return 100%, i ca live with that lol. thanks again man i apreacited it

Andrew

motobro

I am reading the thread trying to figure out why my TPS is holding the throttle open a half an inch and I all of the sudden realized that I have put it on the wrong way!
DUH!

Kiroshu

Have you had any recnet timing belt work at all? It might be jump timing and be off by a bit? Whats its idle is it set high to cover up the reg idles rough run? On the timing tab it should be alil advanced and not way to much and def not below bit alil advanced near 2. I wouldn't think you have a goofy TPS but maybe so.

burnttoast

Hi i just wanted to say thank you for the great information I bought a used 4runner from a guy who spent $5700 on a long block and instalation with all tbelt w-pump ect,also in the back was a fuel pump,filter,coil,wires,distributor ,pickup coil,well he just was done spending money...700 bucks and it is mine after spending 10-15 hrs trying to figue the truck out ran good at idle but backfired and no power but it ran pretty good anways i found this link and one was if the timing light jumped back and forth could be one cam off a tooth so sure enough i took it apart belt was on backwards and not all on tdc.fixed that but still had trouble timing it then i adjusted tbs and now runs perfect thanks guys i feel sorry for the guy and that shop took him for a rde.