Help!!!

I have a 92 Caprice with a 5.7L TBI and a TH-700R4. I have some electrical problems and problems with my speedo. My speedo works in reverse, but in drive it doesn't kick on until i drive about 7-10 miles. Also my computer seems to "fail" sometimes, bringing up service engine soon light. When this happens car runs like crap. Plz Help. The 350 runs sluggish also, is this from bad timing or motor need rebuild? (169K) I will get the computer codes tomorrow. PLZ HELP!!!

Get a paper clip and get the codes. Then we can help.

I have a 92 Caprice with a 5.7L TBI and a TH-700R4. I have some electrical problems and problems with my speedo. My speedo works in reverse, but in drive it doesn't kick on until i drive about 7-10 miles. Also my computer seems to "fail" sometimes, bringing up service engine soon light. When this happens car runs like crap. Plz Help. The 350 runs sluggish also, is this from bad timing or motor need rebuild? (169K) I will get the computer codes tomorrow. PLZ HELP!!!
The code might be for the EGR valve/solenoid. Mine would do the same thing, so I eventually checked the codes and unplugged the EGR valve. It runs MUCH better now.

I agree. Even if the EGR valve isn't causing a problem, disable it anyway after you've fixed the existing problem. Disabling it will prevent problems in the future, and will keep exhaust out of your intake.

Methinks there's something to that "speedo doesn't work" and "service engine soon light". If the speedo doesn't work, then the VSS can't do it's job, and that throws the computer into convulsions basically throwing the car into "open loop" or "limp mode" operation similar to what happens with a bad EGO sensor, where the computer reads predetermined specs for operation at a given RPM from a table in the ROM vs. real-time data from the sensors themselves. From a performance and economy standpoint, this arrangement is almost always less than optimal.

If your car has an electronic speedometer, the sending unit (along with the VSS) will be mounted on the driver's side of the transmission along the tailshaft, in the location of a conventional speedo cable. If the speedo is mechanical, the cable drives the speedometer (the VSS in that case is mounted to the back of the speedo) and if the cable breaks, the cruise control breaks, or the speedo gears strip, the VSS won't report.

How do u disable the EGR valve??? I have a digital gauge, yes and I have tried replacing the sending unit on the VSS, but somehow I got a part for a 4L60E, not a TH-700R4 and they won't swap it or refund my money. GRRR! So im not sure what to do. Left computer at school, so I will get codes hopfully tomorrow.

All you need is a paper clip to get the codes on a 92....