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930_noob 930_noob is offline
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Join Date: Oct 2009
Posts: 15
Installed Digital WUR - AFR problem

Hello fellow Pelicans! I am a new member of the Pelican forum. My mechanic just installed a UTCIS-PT digital WUR last weekend and I am still tuning it with my car 87 930. I used the base map of the new digital WUR. It was OK on the warm up cycle wherein my car started and idled good. After the warm up cycle is done, I see that my AFR is a rich at 13.2-13.5 and I am reading my computer (UTCIS software) that the manifold pressure is 0.9, current pressure is 3.0, target pressure is 3.0. After a couple of minutes, my AFR is getting richer and richer. It started from 13.2-13.5 gradually going down to 10.1-10.2 which looks like the engine will die. I adjusted the fuel mixture in the fuel distributor and leaned it until I get 14.2-14.7 AFR. Now the engine is running better. I tried to run the car and pulls ok, but as soon as I reached the stoplight, my AFR was getting rich again down to 9.9-10.2. The car ran terrible. I stopped for a few minutes and started the car again, now the AFR is a little lean 15.2-15.7. I went back home to adjust my digital WUR on the idle side. Going back home, the AFR on idle is between 15.2-15.7, manifold pressure of 0.9, current control pressure is 3.0 and target control pressure is 3.0 at 1000rpm. I adjusted the control pressure on 0.9 bar (manifold pressure) from 3.0 to 2.6 and now my AFR is 14.2-14.7 which I wanted on idle. I turned off the car. After 10 minutes I started it again, itís back again to being rich from 12.9-13.2. Then Adjusted the control pressure form 2.6 back to 3.0 again getting my desired AFR 14.2-14.7. Then after a few minutes, it would go very rich to 9.9.-10.2 which the engine is about to die again.
Itís been going like this back and forth. I just donít why that it would sometimes go very rich on idle that the engine is about to die.
This was not happening when the stock WUR was on.
I hope you could help me with this problem on what to do. I donít know if it is a fuel distributor problem, injector problem or the digital WUR not tuned correctly.
I hope you could advise me on this problem.
Old 10-16-2009, 02:30 PM
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