mattmondo

All,

I plan on bringing the 86 5K CS TQ back to life this winter. In short, put a lot of time and love and parts over the years (too much to list)need a better vehicle than the RWD Benz for garbage weather. A few things needed to make this better

*Diff locks - doesn't seem to have vacuum. Is there a good diagram laying around to share?

*Turbo over boost - gauge pulls 1.6 BAR and shuts down fuel supply. Really annoying! Any way to resolve?

*ACC - Flashing light on control panel at start up. Any good diag to review

*ABS light comes on intermittently - Guessing ABS sensors

*Takes some cranking to start - Guessing cold start valve. I believe there is a test sequence

Thanks in advance!

bradwilcox

ABS: sensors, sure, but how about replace or reseat the ABS relay under dash?

Cranking: test with cold start valve in place but disconnected?

mattmondo

Good idea. I'll try each option and see what happens!

yodasfro

Could be a torn wastegate diaphragm for the overboost issue. Need a mity-vac to test to see if it holds vacuum from the small nipple on the WG cap. If you haven't been here lots of good info. SJM Autotechnik, Audi Technical Service Repair Information
http://www.sjmautotechnik.com/troubl.../10vwaste.html

034 sells replacement WG diaphragms
https://store.034motorsport.com/upgr...35145797b.html

bradwilcox

Also about the long cranking: replace fuel filter; is fuel pump sending a good flow? If you turn ignition key to the right to the final spot before igniting and leave it for 10 seconds, that should tell the fuel pump to start sending; do you hear it if you sit there with the driver door open and in a quiet environment, such as a garage? Do this and after this delayed period go ahead and crank over; does this help? Otherwise perhaps one or more bad injectors?

GroupBquattro

I wonder if you already took care of the overboost issue. 1.4 bar is stock for these cars. One time when I changed my 1.9 bar ECU to the stock one, I put the wrong spring in the wastegate, too strong of a spring; it would cut at 1.6. Once I found the stock (softer) spring all went back to normal.