Team420

Disconnected my tps, and is much much better, no more sputtering, it is less powerfull now tho, than it was when the tps "kicked in", so I guess I'll be on it with my multimeter this week. Will post my results

TOYOTA 1

my freinds truck is doing the same thing. so we unhooked his tps and it ran way better. it just gets horable mpg's now. subscribed!

pauliep13

Hey 420, I see in your avatar that you've been in the water a few times. The thing I forgot to add in my update was that when I yanked the Bosch O2 sensor, there was water and a little bit of corrosion starting to form in the plug connector. I'm sure this didn't help the problem either. Ya might wanna check it out.

Cleaned it out with electrical connector cleaner. $5-$7 at the auto parts store. Slapped in the new O2, and wrapped the connector plugs with electric tape.

So far about 3 weeks has gone by with no symptoms. I'll keep y'all posted if anything changes.

Team420

Thanks for the tip, the truck in the avatar is my 93, the 94 is the one with the surging, and I have no idea if it's ever been in the water or not, I DO however know that the downstream o2 is shot, and I DO get "CEL" 24(the heater is shot), I just don't see how the post cat o2 could cause this type of problem....
I figured that the pre cat o2 would cause this type of thing tho...so I dunno, I'm gonna drive around a couple days to see if it comes back...then adjust the tps...hopefully this is my problem. If not.....his is what I'm gonna do...

http://www.empirepao.com/
Check out the o2 simulator....This is only for the post cat(sub) o2, and since I'm eventually goin to gut my cat anyway....I'd rather spend the $ on this than a sensor.

Team420

How much worse is it now? Also...auto or 5spd....I would expect more drastic fuel consumption with an auto... It will shift a lot sooner, and you would really need to give it some.

de6w6it

I just did the same thing, i had previously tried a splice in bosch as part of my many months long quest to fix this issue, but it had same symptoms. This time I got the correcct denso one with the correct plug and all. I found the same thing as you, slight moisture in the plug connector. Best I can figure, it is because my cap leaks a little at the seam with the roof, right behind the drivers seat, water probably soaked through the carpet and pools on the floor trapped under the carpet, right where the connector is for the o2 sensor. so i pulled the connector up through the seam of the two carpets, so the connector is no longer under the carpet, and is actually sitting an inch or so above it, to try and keep it dry. It has been only a few days, and no driving in the rain, so we shall see what happens. i will post my findings after i drive in the rain.

Swansen

i'm going to add to all this, because my 88 PU started to hate acceleration as well. Right now i have a 21 code coming up, which is O2 heater or O2 short/ground. I just replaced my Bosch sensor with another Bosch, and no avail. On that, i'm also going to replace my coolant sender and sensor, as my temp gauge isn't working. (checked connection, their fine) Lastly, just ordered a Denso, so we'll see how that goes. Oh yeah, tried unhooking the TPS, and i had more of the same. Oh yeah again, like i was saying, i have the trouble code up, and it will turn off every now and then, and when it does, the sputtering goes away. So, i think i just got a bad O2 sensor from the get go.... OR! i have a wiring issue some where... lets hope not OR! AGAIN, the splice connector thing is messed up, and thats why the code goes off for a bit/like i was saying, the sensor might just be bad from the get go. Ether way, i'm putting money on the O2 sensor being the issue, or my issue. On a side note, its not a vacuum leak, as we did a vac leak test, and it came up that the EGR vacuum regulator was leaking, so that got replaced.

TOYOTA 1

5spd and his mpg's sucked, but all is well now. he purchased a new tps and had a guy he knows do the work. now it runs like it should and gets way better mileage.

Dipstik_90

Sorry to revive an old thread but; I recently had the same issue. No power till like 3500rpm then it was like someone hit the nitrous. I unplugged my tps and it didn't help, then I read up on Denso o2 sensors. Mine is new from a company called Standard but I thought it couldn't hurt to try. Well I unplugged it today and I got most of my power back, and like new throttle response. I guess I'll be ordering a Denso sensor shortly.

hmmwv15

A little bumpage for this old thread, I won't apologize for doing it either, cause yal would tel me to search if I had posted a new thread.

My 85 4runner (with a 93/95 engine) is doing the same thing after doing a timing chain job on it. It ran fine before, now it sputters in low rpm's/when accelerating. When it's not warmed up it will pop through the intake if you punch the gas pedal. I didn't disturb anything but the timing chain/distributor, what could it be? I have moved the cam gear over a tooth both left and right, and that's not it. I have also moved the distributor back and forth, not it either. Ideas? Criticism? I'm open to anything right now. I'm DESPERATE!!!

de6w6it

Well, after putting in the new o2 sensor, everything was pretty good for a while. Occasionally it would still sputter for a few minutes before it warmed up, but again only when it was wet out. It seemed pretty tied to the o2 sensor connector under the drivers seat. So i sprayed in some wd40 and put some dielectric grease around the seal of the connector and plugged it back in. It was great the next 2 times that it was wet out. Then this morning, I warmed the truckk up as usual, and when I came outside to leave, it had died. I started it back up and left for work, and it behaved worse than it ever had. It ran worse the more pedal I gave it, until WOT when it kicked in with the usual surge of normal power. The more air I let it, it was almost if it shut off, I couldnt hear it firing at all, until WOT or barely at idle. So best I can figure, it was running super lean.

de6w6it

I pulled over and popped the hood. So I unplugged the o2 sensor, sprayed in some wd40, and did the same with the tps and the afm. Didnt seem to make a difference, so i decided to turn around and sputter home. On the way home, about a half a mile down the road, the truck ran fine all of a sudden, like whatever was wrong just dried out or something. Here is a list of things I have done/swapped/tried/checked, maybe someone has an idea, maybe it will help someone else:
swapped ECU
swapped AFM
new o2
new tps
adjusted tps
new plugs, wires, rotor and cap
siliconed distributor cap and pickup wires coming out of dist.
it has the rubber boot on it
made a water shield for it (distributor is not getting wet)
new engine coolant temp sensor
cold start time switch and injector dont have an effect
new cat
new muffler
all new vacuum hoses
engine is a reman so all gaskets are new, and spraying starter fluid shows no leaks
only happens when wet out/raining/moist
adjusted valves to spec
Any ideas?

de6w6it

I forgot a few things i have done/tried/checked:
cleaned TB
seafoam
timing is set
re-did all grounds
new battery cables
new main fuel line
new fuel filter
no CEL or code
egr blocked off
similar to 22mr2's issue, when first started up in morning cold, will run fine, as soon as it switches to closed loop, it gets all messed up:
posted by 22mr2:
Since I got it to happen for a few days, I can give a better description of the problem. The truck starts right up, every time when it is cold. Runs fine right up untill the temp guage is in the switching from open to closed loop range. As soon as it hits this point, thats when it starts acting up. Off idle cruising is fine. Its when the throttle is in the 1/4 to 3/4 throttle range where there is 0 change in engine power. Push it past 3/4 throttle and its fine. There is no miss, no stumble, the only change is in the soundd of the air going into the throttle body. Whats odd is if you hold the pedal dead still in one of the dead spots and wait 6 seconds, it kicks in as well.
It also only happens shortly after a decent rainstorm and will do it for about 4 days after. A week without rain and truck runs great.
I had thought o2 as well, because of the timeframe where it starts acting up, once it starts going into closed loop and the computer now looks at o2 readings. Changed that as well.
Also relooked into the egr(this has no egr temp sensor) and tried running it with the vacuum hose pinched off, no change. Tried yet another afm and no change.
Thought I had it pinned on the vss, had read a tech article in motor magazine about a frequency issue in the sensor output that was just like my problem but another sensor didnt fix the problem.
Also had thought it may have been a moisture issue in the coil or the ignitor and swapped 1 off my other truck, with the cap and wires. Nope, not that either.
There is no vacuum leak, except for the ones I keep making when disconnecting stuff! I havent checked the fuel pressure, only because there is not a total loss of power, just in a specific area of the throttle. Although I tried another tps which passes all of the resistance checks, im starting to think that I have a wiring issue somewhere in that circuit.
Waiting for rain again!!!

de6w6it

he found a short in his o2 sensor wiring, but i cant seem to find one. maybe i need to look further up the harness.

DupermanDave

I'm having the same issue and I just replaced my coolant temp sensor. Mine didn't help at all, but hey, I got a new coolant temp sensor that will last 20 more years and 240,000 more miles.

Not to say his issue isnt cause by the coolant temp sensor. But the symptoms sound just like mine, and he's checked everything I have so far (plugs, wires, timing, TPS, etc...) I'm still trying to track this down.

bikerbob

I am now having the same issue. Mine did not occur till I replace the TPS with a new unit.
It is kind of fun to drive, I can't coast, only accelerate or slow down. My friends get a kick out of it.
I'm going to replace the O2 sensor and see if it fixes it.I have all ready done all the other stuff( tune up, seafoam, tps, etc.) in the last 6 months.
Is there any reason this would happen after I replaced the TPS?

de6w6it

it needs to be adjusted properly or it could cause some issues, i think 4crawler has a writeup on adjusting it, either there or 4x4wire, sorry, i forget. i would try that and go from there.

bikerbob

When I installed the new TPS I adjusted per 4crawler's site and it didn't work. So I went back and reread the instructions a few times and I was doing it wrong. I redid it and it is adjusted to spec, but I still have the acceleration issue.

de6w6it

For what it's worth, last night I found something I believe to be the culprit of my issue, but time will tell when I see what happens when it rains the next time, which hopefully will be tomorrow here in Jersey.
I followed the o2 wires from the sensor through its harness to make sure there were no abbrasions or shorts or anything. I took off the driver's side kick panel, and found a hot wire coming directly from the battery that the PO had obviously run to a switch for fog lights or something, that they had just cut and tucked into the kick panel. When I found it, it was lying on a damp spot of seriously rusted metal. My hypothesis is that it is a spot that gets dripped on when it rains, causing the rust, but also causing a pool that this hot wire had the opportunity to short to. I checked the end of the wire, and there was voltage present, and it was green with corrosion, and it was lying right next to the plug from the harness coming from the o2 sensor and other wires. This arcing could cause any number of issues, including the issues that I was having. Also, a few days ago, I came out to a dead battery for no apparent reason, so now I am thinking it could have slowly been drained by this short. There was a fusable link on this wire, but with such a high resistance connection through water/rust to ground, it obivously didnt draw enough current to blow the fuse, but was enough to possibly drain the battery after a few days and to cause enough voltage drop to affect the 5v sensor circuits and/or arcing to produce enough noise to affect the sensors signals. So I angrily ripped the wire out and am waiting to see what happens the next time it rains.

de6w6it

So, apparently, the loose wire was at least not the whole problem. It has rained lightly a few times since I found the wire, and everything was fine. Today is has been raining a lot harder for longer, and lo and behold, same issues as always. Back to the drawing board I suppose...