opytaylor

Sobi had my 1990 max for a couple months now, ive replaced a few things like the plugs, wires, cap, button, MAF from a junk yard along with TPS. The car runs fine its just that it shifts from first to third and i cant seem to find out way... can anyone help

chrome91

iTrader: (1)

limp mode usually doesnt let the vehicle rev over 3000rpm, sounds like maybe a speed sensor or sensor in the trans is bad. can you manually shift it from 1 to 2?

opytaylor

No not at all...its been that way since i bought it. And i cant drive in o/d because when i do and i get up to about 60mph it seems like my tranny slips and it jus revs up..

maxima278

iTrader: (3)

Sounds like a simple case of tranny going bad to me.

opytaylor

I dont its the tranny fluid still looks and smells great. I leaning more towards some kind of sensor or something i dont know which one it could be.

CapedCadaver

iTrader: (8)

didn't you already have a thread about this a month or two ago? we had been discussing some stuff back then but the thread went cold.

chrome91

iTrader: (1)

trans fluid in mine looked fine and didnt smell burnt when the trans took a dump.

Laevateinn

iTrader: (3)

An auto trans only needs vehicle speed and engine load for proper shift timing. other sensors like temp sensors are just for safety stuff. Limp mode will leave your trans in only one gear, typically 2nd or 3rd, so you have to give it gas from a dead stop to roll it forward.

Car's mileage? or tranny's mileage if it has been replaced?

shiloh51933

iTrader: (5)

Do a stall speed test...google if you don't know how.

opytaylor

Yea we did but we couldnt figure it out and that thread was on a few other things also so i jus figured id start a new one

opytaylor

The miles on the car is 170xxx i dont think the tranny has ever been replaced. But when i bought it i did a tranny flush so i mean it help a little bit onn the shifting from the two gears but didnt fix the problem

Laevateinn

iTrader: (3)

perform a pressure test per port in the trans.

What kind of tranny "flush" was performed? Some use ATF to flush the system with a flushing machine, while some use chemicals. Just so you know, a "flush" is different from "drain & refill." From experience, tranny flushes destroy seals most of the time.

How did you know that it was only shifting from 1st to 3rd and not 2nd? I looked at the clutch and brake operation of the RE4F02A (since you mentioned a "cap" so I assume that you don't have the viscous LSD type), shifting from 1st to 3rd requires the trans to release the one way clutch and apply the high clutch. It's either something in the valve body of the trans has a cross leak between the hydraulic circuit of the band and high clutch OR the band is worn out. With the band worn out, 2nd and 4th (O/D) will be slipping or will plainly not operate.

To confirm if it's the band, try driving the car in manual-2 or manual-1. It will not upshift to 2nd if the band is wornout. Yes, manual-1 also uses a 2nd gear.

opytaylor

I did a drain and fill myself not it doesn't shift as hard as it did but it didnt fix the problem so i took it to where i use to work and they did a t tech on it for free. Which they flushed out the whole system and it still didnt fix my problem..and as far as which gears its in thats just what i think because when i take off i have a lil bit of pick up but not much then i have to let off the gas to get it to shift into the 3rd. While its in third i have no acceleration at all and my rpms is at 4-5 grand when im running at 80mph+. So to me its seems to be third that why i think ots 1st to 3rd

Laevateinn

iTrader: (3)

Still inconclusive. Stall test + pressure testing. You can DIY or have a shop check perform it for you. Either way, I'm leaning towards an overhaul.

opytaylor

Thx for all the help and advice. I'm gonig to try stall + pressure testing as soon as im not working a 12 hour day. As soon as i do i will let you guys know..
Anymore tips and/or advice would greatly be appreciated....

opytaylor

Im still having the same shifting problems but now it seems like im losing alot more gas milage. I dont know what it could be any help??

Hectic

iTrader: (20)

"tranny fluid smells great".

LOL, first and last time anyone will say that.

DanNY

iTrader: (14)

170K? orig transmission?

time for a rebuild.
in the chance you think that it's not that...you still need to open the VB up to check to see the shifts solenoids are working. you did mention that the transmission slipped a few times so yeah clutch packs are toast.

stop trying to skate around the problem. YOU NEED AN OVERHAUL...change the ATF all your want. it's not going to fix a major problem in your transmission.

opytaylor

Ok thanks alot i guess its time to rebuild my tranny. I was just trying to see if it could have been a sensor or relay or something a little cheaper.