iamsuperbleeder

Well, I put in a new, well, technically used AMF, and brand new Bosch O2 sensor part # 15711 scored of eBay for $40 brand new in the box, ran some Sea Foam through the tank and through a vacuum line, installed my new intake (I've been busy with this thing, lol), and the truck is almost back to running like brand new! Got some new AC Delco plugs I'm about to put in because mine are fouled out from the rich running (decided to go a heat range hotter and see what happens), and still have to reset the ECU, and hopefully everything will be as it should.

*Note, I only replaced the AFM because I destroyed it myself by trying to adjust it.

Snotrocket

I'm shocked you seafoamed AFTER the new O2 sensor.

I'm about 99% sure thats what killed mine in the first place.

NwRunner

carbourator?
My friend had carb issues on nova, it did the same thing.

fishon1213

Plugged fuel pump pickup screen? I had an issue with that but my truck sat 9 years longer than yours.

iamsuperbleeder

Oh, my bad, not in that exact order, lol. I actually Sea-Foamed before the O2 sensor. Here's the exact order the things were done...

1 - Replaced the AFM and threw the intake on at the same time
2 - Put some Sea Foam in with a full tank the next day
3 - About a half a tank later I ran Sea Foam through the vacuum line
4 - The next day, replaced the O2 sensor
5 - Put in new plugs and reset the ECU finally (should have done on each step, but oh well)

The O2 sensor and ECU reset where done today (er yesterday rather seeing how its 12:45 am now on the 25th ). There's still just under half a tank of gas in her with the Sea Foam that I'm run'n through it... added to the gas, I couldn't imagine it harming the new O2 sensor; through a vacuum line on the other hand, it's very possible.

So far I'm very pleased. Has a LOT more pickup than it used to and will only stutter after startup if the AC is on, but that's because I've got issues with my AC throttle-up valve. A quick flick of the throttle fixes that. Can't report back on my fuel mileage, although I really hope this solves it. If not, the TPS is next.

A lot more low end torque now too... took a short-cut to Walmart today down a trail and buried the rear end in some soft sand in 2nd gear, lol (thank god for 4wd as it was just me and my buddy out there with only my truck ). She would NEVER grab second before, now I can't wait to see if she'll pull a good dough-nut after all this, lol. What's the fun in fix'n it if you can't play with it, right?

I know, I know...

Main reason I think for the problem; as mentioned many other times on here, the O2 sensor. It probably wouldn't hurt to change plugs out afterwards too; at least pull them and look at them... mine where shot.

ToyYoda

I swapped out the AFM, the computer, fuel filter and cleaned the cold start
injector and it still does it. I'm going to try swapping out the temp. sensor
today. It seems like it's giving a bad reading and causing the engine to run
lean maybe. Although all 4 plugs looked perfect, it might not show signs of
rich or lean if it's only intermittent.

A friend of mine said he had that problem which was almost identical (even
the popping through the intake) and it turned out to be a dirty fuel pump sock
so that's another thing I'll definitley check out but the only thing that makes
me think it's a sensor still is that it goes away after driving it. Maybe it's not
getting enough gas needed for startup? Or maybe the ignition control module
it starting to go bad?

de6w6it

the wires go up into the body, i spliced my wires in, so i did not actually unplug the old wires, i can not see the actual plug, does that rubber boot coming out of the body cover the plug itself? so if i remove the boot, i should be able to get the plug and check it out? it actually is better since the new o2 sensor, now it happens exactly as before, but about ten minutes after the truck fully warms up, even if it is wet, the problem goes away, if it is dry, it doesn't happen at all, so I think you may be on to something with the plug getting wet, just want to know if you get to it from underneath, by taking that boot off, or if you have to go from inside the cab or something to get to it.

ToyYoda

I put some seafoam in the gas tank and did a little bit in the intake (hardly any at all) and the problem is about 60% better than it was. I'm going to try pouring more down the intake and see if it goes away completely.

Has anyone else with this problem tried seafoam?

iamsuperbleeder

Sorry to quote myself, but I did, lol. Helped a little bit, but I also replaced a bunch of other stuff at the same time.

ToyYoda

Ok....so the problem came back right after I posted.

de6w6it

well, I ordered a new engine coolant temperature sensor, should be here in a day or two, one of the few things I havent replaced, the old one doesn't ohm out spot on, though it isn't way off.
Also, I checked the connector for the o2 sensor, and it looks dry as a bone, even when the problem is occuring.
will post results

ToyYoda

I have another ECU water temp. sensor hooked up just resting on the manifold and my truck has been running a lot better but not 100% still.

I will be so happy to finally fix this stupid problem for good.

hodgepodge79

my '87 22re is doing the exact same thing. The first time was about 4 months ago, but then quickly went away. The problem then came back to stay about two months ago. Smooth idle, rough acceleration till about 3000rpm, WHAM!!, accelerates like crazy.
I've got a 1-yr old Bosch O2 sensor, and a fuel filter with 30K miles. I'll look into the coolant temp sensor, TPS setting, and possibly the injectors (290Kmiles).
I'll post my findings.

de6w6it

so temp sensor didn't really change things.
i pulled of my distributor cap, which is only a few months old, and the points on the inside were full of carbon, the rotor was covered in carbon, there was a small puddle of greasy dirty water in the bottom of the distributor. so i sandpapered the contact points, to clean them up, I sprayed some m.a.f. sensor cleaner (its safe for electronic sensors, and it dries super fast) in there and wiped everything off, which got rid of the water and the grease and dirt, and put the cap back on. I found a boot on ebay, put that on. sprayed a little wd40 in there to try and keep water out. one more thing i want to look at, is there is a hole ( i have no idea what its for) in the base of the dist. like if you take the cap off and look into it, its on the bottom. I am going to seal that up too. seems to be much better when its wet out now. i also want to go to the dealer and get a new o ring which seals the cap to the base. i will post how plugging the hole and the o ring work, to see if it clears everything up compeltely.

TOYOTA 1

my buddy's 94 is doing the same thing runs ruff with no bottom end power till 3,000rpm then kicks in like nos. so i unplugged his tps and it idled up but runs way smoother, got its low end power back and doesnt do that nos thing. my question is who's got a good used one for sale?

toyotc78

check your timing it sounds like your your timing chain guides are busted and there is way to much slack in your timing chain

de6w6it

well, I sealed up the distributor as best as I could with some ultra black sensor safe rtv, put the boot on that i got from ebay, and it still does it, seems to take longer to happen, like I have to be driving on a wet road for a longer period of time before it starts happening, but it seems to go away faster now as the motor warms up. again, it never happens when its dry out.
so yesterday i made a splash guard type thing, the comes up from the power steering idler pulley bracket, goes up in front of the distributor, and over the top of it, and is secured to the top of the valve cover with a spare bracket hole. i am hoping that this will keep all the water coming through the radiator and through the fan from being blown directly on the distributor. it is rainging today, so we will see what happens, didnt start doing it on the way to work, but it usually doesn't, it takes time to build up and will do it on the way home, so i will post my results.

de6w6it

well, it did it again the other day when it was raining and i pulled over to check things out, and absolutely everything under the hood was bone dry, so I have no idea what can be getting wet. I checked the pass side kick panel like thook suggested, but it was dry there too, as far as i could tell. I guess there are only a few things left it could be?
gas tank area
water literally going in intake (which I doubt, but possible)
o2 sensor (which is brand spanky new, behavior didnt change)
enough moisture in the air that it gets in to distributor/intake/some electronics, and makes it malfunction, but does not appear wet.
coil/ignitor (possibly cracked??)

94svt50

Change your plug wires? Maybe getting wet and if there is a crack in the insulation maybe its grounding out abit?

de6w6it

the wires are only a few months old, I changed them because of this issue, and after replacing them, the issue did not change. thanks for the thought though. every time i open the hood, I look at them and the cap and think to myself that it really seems like that is the issue, but they are both new, and i have checked them numerous times for any damage or irregularities