So, I was complaining to a guy at work about how I was driving my buddy's Jimmy when the 307 started running rough, then while I was trying to trouble-shoot that, the th350 quit shifting. Without even hesitating, he said, "You've got a vacuum line to the modulator valve leaking."

The more I thought about it, the more sense it made. It explained the miss-fire, the transmission issue, and the power brake issue that I hadn't even thought about yet all in one fell swoop.

I was reminded of a couple of things:
1) There is really no substitute for experience. I've never had a vacuum leak cause a transmission to quit shifting, I didn't even know anything about a modulator valve, much less how it worked.
2) Sometimes, it just takes sombody else who is removed from the situation to look at it objectively.
3) A '71 Jimmy is a REALLY fun truck to drive.

I went home, fired it up and followed my ear to the GAPING vacuum leak (it was hard to hear over the exhaust unless you were listening for a vacuum leak), and cured all the problems in two minutes with a grand total of zero dollars invested in the repair.

awsome!

:cong:

Heh heh, go figure. :lol:

:thumbs:

:cong:

Great Story There are some awsome minds on this board

That one has bitten me a few times. If the tranny quits shifting, but you can shift it manually that's the first thing to check. I thought my tranny was toast 'cuz I was snatching some logs around in my woods when it quit shifting. I finally decided to look under the hood and found the vacuum line off. :rolleyes:

Good job on that one.

My grandfather's car had been sitting for a year or so. When he passed away we moved it out of the garage and it wouldn't shift out of low even manually. I decided take it to my place to get it going again. I stopped off at the first gas station filled the trans fluid to the hot mark (it was HOT driving in low!)

Problem fixed.

Anyone need a clean '93 New Yorker????? Shifts great!