I am running a HT383E in a 56 Chevrolet. It has Edelbrock runners, Scogin dickey vortec base plate, 58mm Tpis throttle body, Tpis AFPR, 30lb Bosch 3 injectors from South Bay. Fastchip.com made a new eprom for me. I've played with the fuel pressure and have it dialed in at 47psi with the vacuum line unhooked and the integrator and BLMs are right on the money. We had some trouble with small vacuum leaks but, now have them 100% fixed verified with a smoke machine. The motor has never ran so smooth since we got it running a couple months ago.

So my question is can the parameters for the Maf burn off be widened or taken out completely from the eprom?? Everything is brand new on this motor. Brand new wiring harness from Painless, new ESC, all new relays, every sensor and plug is new we have tried 3 ECMs, 2 MAFs and keep getting code 36. I am using the computer out of a 1988 Camaro the 165 computer.

On my snap on scan tool I can see the computer call for the burn off after the car is shut off if it is in closed loop. The burn off will last about 15sec. I can see the wire get hot so the burn off is taking place. I don't know what else to try. I'm about ready to take the bulb out of the service engine light and just check for codes every now and then. This motor swap has been quite challenging with a lot of bumps in the road. I think we finally have all the bugs worked out except this code 36.

Any ideas welcome. I have learned a lot from reading Thirdgen threads you guys rock.

 

The 36 is one of the tougher codes to diagnose.

Here are some things to check:

1. The MAF Burnoff relay should have a constant 12VDC supply (battery voltage) on both the 'E' terminal and 'C' terminal (via the orange wire).
2. The 'B' terminal should switch to ground through the ECM output transistor within 20 seconds of the engine shutting off and the oil pressure switch opening. The ECM awaits the loss of power on its 'B2' terminal (Fuel Pump Voltage) before it can initiate the burn off cycle.
3. When the ECM commands a burn off cycle, the relay should close, and 12VDC is switched to both the 'D' terminal on the MAF Sensor itself, and the 'D' terminal on the MAF Power relay.
4. Power is routed through the N.C. contacts of the MAF Power relay to the MAF Sensor to enable the MAF Sensor electronics package. This is critical, since the MAF Sensor must report a signal back to the ECM to prove a good burn off cycle. This is also why a failing or incorrect MAF Power relay can cause a MAF Burnoff error.
5. Upon receiving all these signals, the MAF Sensor hot wire is heated to full incandescence, and the MAF Sensor reads the hot wire current at full. This causes the MAF Sensor to report a full, 5VDC saturated (non-duty-cycling) signal to the ECM.
6. Upon receipt of this signal, the ECM registers a complete MAF burn off cycle, ungrounds the 'B' terminal of the MAF Burnoff relay, and is satisfied.

NOTE: Any interruption of the cycle will cause an error, and subsequent error code. This includes marginal relay contacts, poor connections and grounds at any point, and intermittent operation of the auxiliary oil pressure switch, since any voltage from the oil pressure switch will indicate to the ECM that the engine is not shut down, effectively terminating the cycle.



Other things to check:

1. The MAF Power relay should have a constant 12VDC supply (battery voltage) on the 'A' terminal (via the orange wire).
2. There should be a 12VDC supply whenever the ignition is ON at the 'B' terminal (via the blk/pnk wire).
3. The 'E' terminal should have a good ground at all times through the blk/wht wire.
4. Both the normally closed and normally open contacts of the relay (from terminals 'E' to 'A' for N.O., and 'D' to 'A' for N.C.) must be operational and reliable (see above).

Obviously, your burnoff system is initiating the cycle, and the burnoff relay is powering the sensor wire to incandescence as it should. The question is whether the 5V current sensor signal is getting back to the ECM and whether the fuel pump circuit is interrupting the cycle, preventing a successful completion.

 

Thanks so much for the detailed response. We will start trouble shooting Tuesday when I get off work. Thanks again John