Help needed! Two problems, which I suspect maybe related. 1. Poor running at small throttle opening upto 3k rpm, so making driving around town very difficult with lots of kangerooing, driveline shunts and not running smoothly. 2. It is particularily bad after a hot restart with inability to idle, lots of missfire and popping with the exhaust smelling of a rich mixture, again all at 2-3krpm partial throttle opening. This second problem goes after the engine has been thrashed for a few minutes, leaving only problem 1.
Normal cold start up is fine as is the idle. Engine is fine if driven hard, and the engine revs freely and seems to produce full power. The engine sounds fine on overrun with no pops and bangs. I did wonder if it was using more fuel than it used to, but I haven't measured this.
The setup is standard 1994 1400 supersport with SS ECU, forward facing plenum with 56mm stepper motor TB, 'blue injectors', dry sump, cam timing set to inlet 65 exh 45 thou at TDC.
This setup was working fine at the end of last year on my 1800 installation, with the exception of the injectors which were changed back from 'cream' to the standard 'blue' ones. The injectors have not been used for 3 years, were working fine previously and carefully stored.
I have tried resetting and replacing the ecu with a spare. Ive checked all electrical and vacuum connections.
Any ideas?
Thanks. Malcolm