Slight stutter flathead V12
#1
Slight stutter flathead V12
arly Djetronic injection model. Very slight stutter when accellerating, more so the harder it acellerates and most pronounced mid range. Also a slight lumpiness at idle. Exhaust at both pipes have a steady beat but not the even smooth push of a healtjy engine.
Plugs change, dinjectors checked, *and cleaned, new plug wires, timing adjusted, membrane in vac module replaced, ReOpus ignition, new dizzy lid, all injectors clicking. Any suggestions?
Last edited by Per; 10-03-2017 at 03:31 PM.
#3
Also,
The vac operated fuel enrichment switch is not switching.
The throttle switch is grubby, and/or out of adjustment.
The wires IN the throttle switch are failing, very common.
The EFI loom is starting to cross fire, age related now.
The 2 rubber elbows on the bottom of the throttle bodies are failing = vac leak.
There is a potentiometer knob on the outside of the 3CU unit, and will adjust the HOT idle fuel mixture, just like a carby mixture adjuster.
The vac operated fuel enrichment switch is not switching.
The throttle switch is grubby, and/or out of adjustment.
The wires IN the throttle switch are failing, very common.
The EFI loom is starting to cross fire, age related now.
The 2 rubber elbows on the bottom of the throttle bodies are failing = vac leak.
There is a potentiometer knob on the outside of the 3CU unit, and will adjust the HOT idle fuel mixture, just like a carby mixture adjuster.
#4
Stutter, like misfire under load? That is usually ignition. Yes, i see you replaced plugs, wires and cap. Still sounds like ignition. Possibly wire not properly connected to plug or distributor, arcing or faulty spark plug. could be a bad injector, but if they have been cleaned and tested, and it only misfires under load, the injectors seem less likely than ignition.
#6
The following users liked this post:
Grant Francis (10-06-2017)