so as some of you know, my truck goes through bouts of running pretty terribly and I'm still chasing that problem. basically the deal is, sometimes itll run perfectly fine, as it did while I was using it for work yesterday. but later that day, driving it to a doctors appt it was running terribly, acting fuel starved, and the engine would shake the whole truck when at a stop. driving home from the doc's however, I pulled up to a red light, and it started shaking violently, like it hasn't done before and the thing was about to die. the light turned green and I limped it across the intersection and pulled over. i turned off the engine, and restarted it and it went back to running rough the way it normally does. also, i got out of the truck put it in neutral and revved it with the throttle cable so i could listen to it up close, and when i did that it had a weird sound, almost like a higher pitched engine rev. (i don't wanna say it sounded like a fart can civic but it almost did.) and also there was a sort of separate rumbling sound kinda like a quiet lawnmower that you could hear on the back passenger side of the engine compartment. not sure if this could be exhaust, or emissions or something. it made the drive home without any problems other than normal.

my dad thinks the incident at the light was a result of the automatic trans not downshifting... i think that may be possible, but want yalls opinion. the tranny also acts weird in that it shifts from 1st to 2nd very early in acceleration, so it feels weird and its slow accelerating from a stop. i replaced the tps recently but I'm still getting codes for it so could that be part of the problem? also gave it a tune up recently. (plugs, wires, cap and rotor and ignition coil)

pretty much stumped here. can yall help? gonna go throw a little more trans fluid in it cause it looked a little low and drive it to work, we'll see how it does.


*edit*
sorry for the long rambling post, I'm just trying to include as much info as i know

 

update- before work i dumped about 2/3 a quart of trans fluid in it, and when i drove it to work it ran like a champ. i gunned it off the line at a few lights and it took off as quick as i ever felt it. and it seemed to be shifting at the right times too.

also another thing to add to the first post, when i accelerate, (especially accelerating through turns) theres a rattling metallic sound, almost like a tin can full of change being shook around. i have no idea what this is

 

When's the last time you checked your timing?

When I replaced my distributor, and I didn't have a timing light to work with, my engine would sound like the change can rattle you described, until I got it dialed in correctly.

 

don't have a timing light so i haven't messed with timing. is that one of those tools they'll rent to you at an auto parts store?

 

Sounds like your on the right track by looking at the transmission. What year is your truck? If it's got electronically controlled ignition, and the electronically controlled transmission, you need to pull codes. The computer will tell you exactly the issue it sees while running.
Until you pull codes you are just throwing parts at it.

 

its a 96. ive pulled engine codes, not sure how to pull transmission codes. do you have to get a different type of scanner?

 

Less than 1 quart of atf fluid shouldn't matter, shouldn't. When I got rid of my '96 it had 250k on the original trans and engine. Still ran like a champ when I got rid of it. The AODE in it did act up every now and then, extremely hard shifts. I had it flushed and it went back to normal. One problem I did have was the front fuel pump started to go, made noticeably less power on the front tank than the rear. And yes, those trucks still need to have the timing set, just make sure you unplug the wire under the brake booster when you do or it won't adjust properly. I do miss that truck, but my '08 is so much better.

 

Ok so did you have any? Which codes were they? I use a regular obd2 scanner in my 96. The transmission is controlled by the computer that also controls the motor. So if any of those act up, it will set a code.
That being said; if adding transmission fluid helped the drivabilty of your truck, one could presume that your transmission is in need of a service. Drain all fluid from the pan and torque converter and change the transmission filter.
Another thing to check is for vacuum leaks on the egr, tab, and tad solenoids. Even a small leak can foul the readings the computer recieves, causing drivability issues.
I recommend posting your codes here, if you have any, so we might be of further help.

 

let me try and find them. I posted them up here a few weeks ago.

 

KOEO I got:

P0122 which means I may not be done dealing with the tps
P0135, P0141 and P0155 which all have to deal with O2 sensors

KOER I got:

all those same codes, plus
P1000- OBD systems readiness test not complete
P1116- engine coolant temperature sensor out of self test range
and P1001 KOER not able to complete, KOER aborted... so I gues the test didn't finish?

nothing that seems to be for the tranny but again it looks like the test wasn't able to complete