iamsuperbleeder

After 286k miles, this 92 PU 22re is finally starting to give me issues...

All day today I have not had any problems with it. Drove it to work, no problems. Drove it on my lunch time, no problems. But suddenly on the drive home is when I started having some issues...

I have about a 15 minute drive home from my current job ( I say "current job" because this Saturday is my last day there... then my drive will be about 25 minutes every day ). It did good untill I got about 2 miles away from my house and started hitting some red lights.

At every stop, the RPM was different? It normally idles right between 900 and 1000 on the tach ( I know, many are gunna say that's higher than it's suppose to be, but that's where I like it, so leave me alone ). On the drive home, I would stop, and it would be at 1200... I could flick the throttle a few times, didn't change; it stayed steady at 1200... So the light would turn green, I would take off and drive a minute to the next light, stop, and then it would fall down to about 600? Tried flicking the throttle again with the same results; stayed steady at 600...

So I got it home, parked, then the truck idled normal at about 900 rpms for a sec, then dropped about 200 rpms and began to lope like it had a steep cam in it... It would do the loping for about 10 seconds, then idle fine again at about 900 rpms for maybe a second and a half, and drop down again and lope... don't get me wrong, the "cam sound" kinda sounds cool, lol, but the motor's bone stock, so something's not right.

So I pop the hood to see if anything obvious it unplugged, loose, arching, leaking, ANYTHING. I found absolutely nothing. All the plug wires are fine... pulled the plugs, their spotless... air filter looks brand new... all the major electrical connectors like the TPS, AFM, and temp sensor plugins are tight and snapped into place... even went as far as to pull the PCV valve off; it's perfectly fine as far as I can tell...

So I throw everything back together and start it back up... same damn thing... idles at about 900 rpms, then drops to 700 and lopes between 700 and 750 like it has a cam in it, comes back up to 900 for a sec, then does it again over and over again...

So I think "ok, lets shoot a video so maybe my fellow YotaTechers can help me diagnos this problem"... So I shut the truck off, walk inside, grab my camera, walk back out, and proceed to start the truck again. Well, wouldn't ya know it, it idles fine now... I shut it off and started it back up again a few times... ran fine everytime. I let it run for about 15 minutes till the tempuature stabilized... still runs fine.

I'M COMPLETELY BAFFLED!

There's absolutely no symptoms while driving the truck. With the skinny pedal pressed and with the motor under a load, it doesn't hessitate or stutter at all...

I'm not sure what else to check, and I really don't want the thing to die on me here any time soon.

Once I get started on this new job, I'll be making 3 times the money I do now, and I'm looking at a 95 4Runner to buy as my daily driver so I can take this almost 300k beast down to the frame and build her up again. So I really just need this truck to last me about another month or so till I get the other Yote; I'm really hoping it's not something major that's gunna leave me stuck on the side of the road one day on the way to my new job...

But anyone have any idea what may be going on here, because I'm lost...

Thanx in advance guys.

abecedarian

my 88 started acting like that when the ignitor decided to start going out. one moment fine, the next rpm's all over. sometimes it would die.

iamsuperbleeder

I'll have to see If maybe I can borrow one from a buddy of mine. He's got 2 gen 3 PUs with 22re in his back yard; one has a blow HG at the time, and one is getting a sas as we speak. I'll see if I can get one to throw in for a week or so and see how it goes... I didn't think about that man, thanx!

that would kinda suck if that's what it is though... it's about $300 for a new one... unless I can dig one up in a junk yard... unlikely though...

Team420

I got the coil and igniter along with the airbox and vafm for $25 from a yard.

iamsuperbleeder

Well I'm pretty sure I found the problem. The TPS is beyond shot...

The last time I had the intake off and everything apart, I scoped it out with a multimeter, and it had a few spots that the resistance jumped around a bit, but it still seemed to be performing fairly well. So I just reinstalled it, adjusted it right, and just went with it.

Well today on my lunch time, I started messing with it a little more. I unplugged the thing while it was running and the RPMs jumped up about 400 RPMs like I expected. Plug it back it, it almost stalls out. So I busted out the mulimeter, fiddled around with it for a bit, got it to what I though was adjusted right, but as soon as I flicked the throttle, it was reading weird again. I did this about 4 times, and the adjustment kept screwing up every time after I flicked the throttle. So I took it completely off, probed it with the multimeter, and swept it through the range, and the thing's all over the place...

I'm begining to think that maybe that's where my gas mileage has been going too...

So $70 later ( gotta love that employee discount... till I leave this job anyway, haha ), it'll be in tomorrow and I'll throw it on and see how it goes.

Right now the thing runs GREAT with it unplugged, lol, but I know it's probably going to guzzle gas like a v8, but the new one will be on tomorrow.

Thanx for all the help guys. I think I'm still going to replace the coil too; mine's not original; it's one of those MSD universal coils that I got from someone a while back, and I have no idea just how old it is, so that should help as well.

I'll let you all know how it works out, cross your fingers!

abecedarian

yeah, the tps can muck with things that don't seem related. hopefully that fixes the prob. I picked up a TPS for mine from autozone for $79, new.


On the side, got a used ignitor / coil for mine for 80. new ignitor was ~380. I installed the ignitor and put the coil to the side and no problems so far.

I had one of those universal chrome Accel coils in my 91, and it lasted about a year. Started leaking oil all over the place and the truck was misfiring. Swapped in the used coil from the ignitor/coil combo above and the misfire went away and my wife is all giddy now.

So I fixed two problems on two trucks for 80 bucks.

iamsuperbleeder

Yeah, I'd like to install the new coil with a universal bracket to keep it upright; might keep that from happening with a new one.

Of coarse, once they go, they go...

abecedarian

I'm thinkiing the problem with the oil leakage was caused by insufficient ballast resistance causing the coil to overheat. but hopefully, it was just the fact it was laying on its side.

iamsuperbleeder

possibly; I guess if it went bad and made too much resistance it would cause problems...

but I didn't think the ballast resister was 100% nessesary for the truck to run and the coil to last; I though it was just a radio interference preventing thing with the coil... or am I thinking about the capacitor... or are they the same thing...

now I've confused myself...

iamsuperbleeder

Well I threw the new TPS on, adjusted her up right, and it seems to be all better now!

The idle is steady and smooth right where it needs to be, the throttle responce is a thousand times better than before, but think I need to readjust my timing a bit now since it's getting a good reading from the TPS ( I played with it a little when I was messing with the old one on ), only because the acceleration seems a little sluggish.

It's still before 12, so I have all day left... maybe I'll get my lazy @$$ outside again and do it...

maybe...


oh, and for future refference... to get to that damned bottom screw on the TPS, it's a lot less messy to just take the throttle body lose than to remove the t-stat housing, lol.

iamsuperbleeder

well, I found somethings else rather interesting today...

I checked the timing, and it was right on the mark where it should be. I rechecked and toyed with the new TPS that I installed, then readjusted a bit, and when I went to put the intake tube back on I found 2 things...

One, the temp sensor on the intake manifold was leaking, so with the almost 300k miles on the truck, I'm just going to replace that; might help a little.

And 2, on my intake tube when I got it ( it's an aftermarket intake setup; take a look at my pics from my sig if ya wunna see ), it had one port on it if you needed to hook up any extra lines to it. The port was just a hole with a hard plastic nipple threaded into the tube, and I just put a cap on it. Well, it must have wiggled its way off, bucause it was gone today! I don't know how long ago I lost it, but I've been driving around with a gaping hole in my intake tube between the AFM and the TB! So I just used a threaded pipe plug and some teflon tape, and she's good to go now! It runs a bajillion times better, and I still have yet to put the temp sensor on.

Just goes to show, never overlook the obvious I guess...