Silvertop 20 Valve -Soooooo over it!

[jordan]

I run an A/T ECU no problems, I suspect the 4000RPM may be due to your DLI box if you don’t give the ECU a good IGF signal it won’t be happy, it uses this signal to confirm the spark event has occurred.

Regarding the "super rich" what AFR numbers are we talking? I would try disconnecting your O2 sensor and ensuring that OX1 and OX pins don’t have any shorts in the loom. If the O2 sensor is wrong type then it could be telling the ECU to run super rich or super lean as it was in my case. The ECU will run ok will no O2 sensor connected and will stay in open-loop.

Do you still have your idle air speed valve operational? A simple check of water temp sensor and IAC valve is start up cold and leave idling as it warms up your idle should slowly drop down to ~850RPM.

Also I'm assuming that you have already inspected/replaced defective capacitors in ECU as they can cause all sorts of issues.

[knightrous]

I'm not familiar with the DLI boxes, but does it require a timing advance signal? I know with the stock VAST ignition setup on the Bigport 4AGE, if you disconnect the IGt signal from the ECU to the VAST igniter, it will run (the dizzy is wired directly to the igniter like EDIS) but it gets limited at 10 degrees advance. It really kills the ability to rev when your stuck at 10 degrees and will make the car drive like ass, but it's enough you can limp around.

[CILAchainsaw]

Just out of interest, did we ever get to the bottom of this?

[beerhead]

Poor bastard had an air leak. An engine doesn't go very far above idle RPM without extra air, either a faulty PCV, Idle control valve or damaged intake gasket.