This is a 91 syclone with stock td06, AFPR, Kenne bell a2a, 2800 stall converter, cold air, ultimate chip, open downipipe, walbro 255.
I just did a tune-up, cause i was getting 12* of KR and wasn't making full boost.
Plugs
cap and rotor
checked wires
fuel filter
pcv valves
set base timing to 0*
clean injectors
(all of the above done by mechanic)
base FP set @ 50

well i think the tune-up took care of the KR.
at least for a 100 miles. Then i looked into the boost problem.
it turned out that the inlet pipe to the a2a had come loose. i am now getting the boost fast and strong. and i am now getting the boost spikes like everyone was warning me about having a open downpipe. so i will need to take care of that.

but now the truck stumbles alot. When i am part throttle i am getting 2*-18* KR which i think is associated with the WOT stumbling. and the 02 MV fluctuate from 70-900@100%tps. Also my spark advance seems to dip to almost nothing? i dont freaking get it whats wrong now. Just before i fixed the boost problem the 02 MV would be solid 900-970. Could air in the fuel lines cause this?(if it were air in the fuel lines, would it take 100 miles for the air to reach injectors?)Could my pump be going? If you have any recommendations please tell me how to test the particular part in question. thank you

Datamaster Files from 2/22 after boost problem fixed but with KR and crazy 02 Readings
http://www.geocities.com/kmook123/chadf1.zip
http://www.geocities.com/kmook123/chadf2.zip
http://www.geocities.com/kmook123/chadf3.zip
http://www.geocities.com/kmook123/chadf4.zip

 

What Timing and Boost settings are you using on your ultimate? Do you have an Ultimate w/stock injectors or the Ultimate for the 50# injectors?This is going to affect what the Fuel Pressure should be set at.How are you setting your timing?Make sure it was set with the brown wire disconected! Side note, these trucks eat ignition parts like there is no tomorow. I would replace the wires. Your problem may be there. Do you still have the stock chip? You can try to put the stocker back in to se if there is a broblem with the Ultimate (but I doubt it, Brian Green makes a quality product).
You can also check out http://syty.net for more help.

If the turbo is a stocker (17c with an 8cm turbine housing) it is going to boost spike fast with open exhaust (that 2800 stall is not going to help either). I would look into an external waste gate. You can weld it to the crossover pipe and it will give you rock solid boost control. Inovative Turbo Systems has their mini gate, that is a good product.

Check out SyTy, there is lots of information there!


Brian