Originally Posted by Hanr3

To both of you with problems.

Pull the tranny dipstick and smell it, does it smell burnt, if so your tranny is toast.
Is the fluid red or black, red =good, black = bad.

Now onto the more realistic problem, with a little background. The computer controls the engine and tranny as one unit. It reads various sensors and makes adjustments to the engine and tranny shift points based on those readings. 9 times out of 10 when people report tranny problems its not really the tranny malfunctioning, its the engine. If you have either of the above conditions, burnt dark/black tranny fluid your in the 10th category.

The biggest problem with engine performance as you discribed is either a faulty ignition system (typically the distributor cap) or leaking spider injector assemble, another posibility is vacuum leak (vacuum hose or intake manifold).

One of those is typically the culprit, after that we get into things like EGR, MAF/MAS sensor, etc. Do you have an aftermarket air filter, like a K&N? Those things a natorious for depositing oil on the MAF/MAS sensor and causing all sorts of engine/tranny performance issues.

The key here is the moisture. If your truck runs better when its raining, typically that means you ahve a crack in teh distributor cap. The other option is you have a lose electrical connector on the tranny. Look for the wire pig tail on the passengers side towards the back, unhook it and make sure its dry, then reconnect it.

To check for a vacuum leak use a spray can of either, spray it around the engine compartment while the engine is running, if your rpms go up, you found a vacuum leak. False air is another posibility, false air is air that gets in the intake manifold by a means other than through the MAS/MAF sensor, like if the intake hose is disconnected or cracked by the intake manifold. The computer wont be able to compensate for tha false air and it causes performance issues.


As for the downshifting, nothing wrong with it like Kyle pointed out. The tranny has an overrun gear, when you down shift the tranny will spool up until it matches vehicle speed and then start to decelereate. And no you cannot get your tranny to shift gears while going too fast, you may be able to move the lever, however it wont downshift. As for upshifting, it wont shift any higher than you go with the shift lever. However you can blow up your engine downshifting too soon, or upshifting too late. Wathc those RPM's, that pretty red line isnt just a cute color to break up the look of hte dash!

Thses are not high reving engines, they gain most of thier power under 3,000 rpms. In most cases under 2,500 rpms. Sure red line is like 4-5K, however itll be sreaming bloody murder at those rpms.


I hope that helps.

Originally Posted by ski9600

Great post. I've just joined the forums because having similar troubles right now and thankfully the tranny fluid is red, proper level and doesn't smell. I'm getting no SES light, but sure enough there was 3 codes tonight. Two were for O2 sensors, and the 3rd was MAF sensor. We cleared the codes and drove up the pass (I live at 9600' altitude and we drove up to about 10000') and when we got back sure enough there were more codes (three all for O2 sensors) but still no SES light. I will clean the MAF, search for vacuum leaks tomorrow night and also check the fuse for the transmission underhood. Thanks again, Ski /btw, 2000 Blazer 4dr LT Blue, named Debbie

Originally Posted by Hanr3

Thanks.
Welcome.
Which pass? I used to live in Frisco, CO. Elva. 9100.
Good luck with her.

Originally Posted by Hanr3

Your welcome.

Yet again, another tranny porblem solved and the tranny had nothing wrong with it.

Glad we could help.