[mikesarge]

1. Year of engine: 1980
2. US or RoW (Rest of World): US, but 3.1 9.5:1 w/964 cams, supertech kit and backdated FD, no FV/Lambda (FD no. 010)
3. WUR model number: 072
4. Ambient temperature at time of test (in degrees C): ~10
5. WUR Resistance (in Ohms): D'oh! didn't measure. will update
6. System Pressure (in bars): 4.8
7. Cold Control Pressure (in bars): 0.6
8. Warm Control Pressure (in bars): 3.7
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): ~7:45
10. Residual Pressure @ 5 min (in bars): 0
11. Residual Pressure @ 15 min (in bars): 0
12. Residual Pressure @ 30 min (in bars): 0
13. Residual Pressure @ 60 min (in bars): 0


1) So! I think one issue (hard hot start) is a fairly easy one- it's a check valve, probably at the fuel pump, right? I heard somewhere (???) that it could be the FD. It sputters and stumbles, and my AFR gauge shows lean for about 20-30 seconds on a hot start, then it comes back to being quite rich at idle, but drives great, just like normal.

It also looks like maybe the WUR is out of spec? or could a bad check valve (or FD) create artifically-low cold pressure reading?

2) The other issue, that's been a bit more annoying, may be a limitation due to my top end build and somewhat-mish-mash fuel system. it is rich as hell at idle. I can't reliably log this AEM AFR gauge (don't know how- have serial port hooked up, but no idea what program to log with, how to get RPM/load put into it, so usefulness seems limited). Anyway, it seems safe at WOT, pulls really nicely, and a peek at the AFR gauge shows a taper from super lean when I stomp on it (normal), then 14-ish down to 13-ish by redline.

Idle is always super rich, hot or cold, between 10-11.5

Is this just a limitation because I've got these cams, and this higher-comp setup? or do I need to lean it out? or will a pressure adjustment help me out?

Should I take it one step at a time, and rebuild the WUR? whats the next move!?