I recently got my 84 SVO running for the first time in over 5 years. The mods I have so far are Brown tops, adjustable FPR, LA3 EEC, Bob log, 3" exhaust, 3G Alt, aluminium radiator, Gillis valve, and Walbro 255. Also have a rebuilt T3 and a new Ron Francis wiring harness installed.
I set the TPS to .96 and confirmed that is has no dead spots with my analog volt meter. At this point I was able to drive the car around the block but it was running very poor. Smoking slightly but it seemed like it was running rich or maybe had a blown head gasket or something (may have just been the dust burning off). Next I checked the compression, fearing the worst, but surprisingly showed 150 in every cylinder.
I run codes on the car and I got 61 (ECT sensor low) 81, 83, and 84, not caring about the 80's codes as I do not have EGR in place. I purchased a new ECT sensor because the old one was in pretty bad shape. I just replaced to ECT with the duralast brand and think this may be the problem however I wasn't able to get a motorcraft brand at any of the local parts stores nearby. No change in test drive results
I then confirmed the timing was set correctly and it showed 10* BTDC with the spout unplugged. When the spout is plugged in it jumps to 20 BTDC and seems to return to idle normally. Car did not improve after test drive.
Next I bought a fuel pressure tester and taped it to the windshield but the car really isn't able to accelerate enough to see a noticeable change in pressure. Also the pressure when at idle is spot on 39psi and again at this point the car idles fine.
At this point I thought it might be the TFI module and I just happened to have a spare distributor with TFI still intact. Couldn't get the TFI off the distributor on the car so I pulled the whole thing. After I replaced the distributor and set the timing and get the same results.
So I did some searching and found that the ACT or IAT should be run with an LA3 EEC and the new harness instructions say that it should be strongly considered although there are many people that say it does nothing what so ever. After the ACT was plugged into a coupling between the intercooler and the throttle body the car idles at 2,000 RPM so I thought I'd check the timing and sure enough it was off for some reason? This time with the spout unplugged at 10 BTDC it goes to 30 BTDC when I plug the spout connector in? Correct me if I'm wrong but I think it's supposed to be 20 BTDC with the spout connector plugged in?
Sorry for the long post but I know this car is close to running like it should and I need some fresh thoughts about what to do next.