I've been working with Rayapp2 diagnosing this for a while and we're both stumped.
I can setup the motor fine, at this point I've gotten it to run. does 10:1 in boost, pull around a bit when its hot... after around 5 minutes of this it will start to lean out starting at the top rpms and get progressively worse until I can only drive part throttle and barely limp it runs around 18:1. Takes about 5 minute to get to undrivable.
if I cut the ignition and start it up again, it will go back to running normal and 10:1 in boost. the issue comes back faster after that.
I have an innovate MTX-L reading afrs
1982 L28ET with 1983 ECU i have spare ECU's that I've tested.
AFM is reman unit, I've swapped and tested anther unit and tuned with wideband.
all harness connectors have been replaced with kit from fricfrac
ecu connectors are Z31- I've even swapped some of the pins to z31 and retensioned, soldered them!! no more intermittent issues here.
CHTS is new OEM nissan, I have three more than ray lent me for testing.
engine is mechanically sound, I just did a pre-track teardown to check the head gasket and internals.
CAS looks to have been replaced at some point. timing is steady @3000rpm
TPS is adjusted and tested per FSM
Ray personally went through the system and thought the injectors were bad ... I put new ones. in a few days ago no change
fuel pressure is factory spec, flow is good
what else? probably forgetting something. just flying blind at this point, pouring over wiring diagrams testing random wires.
Any ideas? Anyone intimate with the inner workings of early ECCS systems?
note, I am in california. I need the stock ECCS to pass smog. Z31 swap is not an option.
Edited by stupid_fast, 14 May 2015 - 11:28 AM.