Speedometer not working + ECU clicking

[gdolson]

We just got our new (used) transmission in on Sunday. On Monday morning it started and ran great, except that the speedometer is not working, it won't even jump a little. We do have the cable end hooked up to the transmission and turning the end of the cable does cause the needle to jump. How common is it for the speedo gear in the tranny to go bad?

Our other problem now seems to be the notorious ECU clicking, car bucking and stalling. I read the codes and only got a 24-Speed Sensor Switch. I believe this is from the inoperative speedo. Can this in any way cause the stalling/clicking problem? I believe the speed sensor has input to the ECU and can affect fuel flow. The only problem with that theory is that the car will also do the click/stall when it's not moving.

I have the ECU out and will replace the caps and clean up the board. There is some corrosion but no holes in the board. Does anyone have a schematic of that board? There are a couple surface mount components which may have been affected by the leaking electrolyte, but they have no marking to determine what they are.

Thanks,

Greg

 

[LightningGSX]

Whats the component # on the board? C44 and C14 are .01 uF ceramic caps, those are the ones that usually are damaged from the electrolytic caps leaking.I don't have a schematic, but I can tell you what the part is if tell me the component #.

 

[gdolson]

Yes C14 and C44 look mucked up. Also C38 and C106 which are closer to the regulators don't look right. C19 which is next to IC6 also doesn't look clean.

 

[luv2rallye]

This may help: http://www.vfaq.com/index-main.html
Go to Electrical, ECU capacitor replacement link.

 

[gdolson]

That is definitely a good link. I got the 3 electrolytic caps replaced and replaced 3 of the surface mount .01uF caps also. They looked pretty bad. Drove the car last night and it is working so far! (fingers crossed). When doing this, you want to be sure to check continuity between components which are supposed to be connected. The corrosion from the leaky caps will form an insulative layer which solder will not adhere to and won't make connection, even if it "looks" good.

Now, any ideas on the speedometer? Has anyone seen the plastic gear that is in the tranny get stripped? We need to take it out and check it.