Ok, this may be a little long, so sorry about that .

It all started yesterday when I got my '90 stuck in the mud. I was able to "rock" it out of the mud, but immediately following that, the trans (700r4) would not upshift properly, I had to get the tach up to 3500 before it would shift. No big deal I think, maybe I just knocked the detent cable out of adjustment. The kicker was this:

I was driving down the road (in heavy rain) when the car started acting funny, meaning that the tach was jumping like it had a misfire. Shortly after this started, the SES light started flickering, then it came on steady, then flickered, then went out. While this was going on, my speedo went nuts, and then died completely while all the other gauges worked fine. I was really confused, so I reached under the fuse panel and felt one of the circuit breakers was exceptionally hot. Keep in mind it was dark out, and I was moving at the same time, so I couldn't tell which one, but I believe it was the one marked "power acc.". I pulled it into the first gas station I saw, and shut the car off. It wouldn't restart. It cranked over, and had fuel but seemed like no spark. To top it off, the hood cable broke on me, so I couldn't get the hood open to see what was going on. After failed repeated attempts to start the car, I gave up, went inside, got a drink, said a quick "Hail Mary" and turned the key. It started. I drove it home with no problems whatsoever, aside from the shifting problem. The speedo worked fine, no SES light, no misfires or anything. Once I get the hood opened up, I'm going to check my cap, rotor, etc.. The cap, rotor, all that stuff is new (2k on all of it).


Has anyone experienced a similar problem like this before?
'90 firebird with '91 L98 and 700r4 trans.
If anyone can offer any insight, I would appreciate it, thanks.

 

QTA,

Some people have all the luck....

You likely bottomed the car in the mud. You may have damaged or soaked the VSS (speedometer failure), bent or damaged the shift cable and linkage (shifting problem) and bent or damaged the TV cable and housing. I can only presume that the mud/water had soaked some ignition component and caused the tach problem and no-start.

I'd say another "Thank You" for your Savior and get under the car with a garden hose. Start cleaning everything under the car and around the transmission tunnel. Make sure you clean the driveshaft, torque arm, springs and shock mounts, cat converter heat shield, differential housing vent line, gas tank shield, fuel filter, and sub frame channels. Take a close look at the hydraulic lines for the brakes to make sure you didn't damage them.

Take some time to pop the hood open and replace the release cable (obviously).

Good thing it's a three-day weekend...

 

You said it there. I'm in the process of tearing into it right now, but thanks for the pointers Vader, I'll be checking the VSS, and all the cables to see if anything's damaged. I'll post back here and let you know what I find. Thanks for the pointers.

 

Well, I checked everything out under the hood today, and I didn't see a thing wrong. Edit : Everything checked out fine, except for a code 43, which I believe is low voltage at EST circuit. Think the rain could affect that? Either way I'm completely stumped .

 

QTA,

The "43" should be for an "EST failure - spark retard too long." Chceck the connector at the knock sensor, and check the sensor itself for damage. Mud/water packed in there could be an issue. Without a knock sensor signal, you'll get the '43' and generally poor performance. It shouldn't affect shifting, however.

If I'm reading your thread correctly, the engine is running, but the transmission isn't shifting at the correct points, right? If that's your only problem, I think you're still looking at the linkage and TV cable. You may have also crimped a transmission cooler line, and the line pressure in the transmission is lower as a result, so the governor never allows an upshift.

 

The 43 was set when the car was acting funny, and before the no start problem. After the car started (and the alleluia chorus finished playing), I took it home and pulled the codes, and the only one it gave me was 43, however the engine was running fine on the trip home, and is running fine currently. I'll have to look at that knock sensor and see if something's awry there. The only current problem now is the upshift ordeal (not shifting when it should be), which I reset the detent cable and have yet to give it a road test as I'm painting the front end today, but I'll let you know as soon as I get it on the road what it does.

 

That DTC 43 will remain there for the next 40-50 engine run cycles, or until you clear it. The ECM stores the codes for diagnosis, so clearing the problem doesn't automatically clear the code. You could disconnect the battery for a few minutes to clear the ECM, then see if the error repeats. It's also a good excuse to clean the battery terminals.

 

I'm going to do that sometime today and see if it sets a code again when I get it on the street. Hopefully it was just mud or something gumming it up.