Login Register

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
1989 sidekick misfire when cold or when under electrical load
#9
above is generic
cold only misfire.
it's too rich, a tuned up car, spark good , is too rich
the fact turning on the fan for faster idle tells me and i bet if you raised rpm to 1000 using your right foot it would do the same thing , at 1000 RPM , and will after all 1000 fast RPM only
The ISC can never cause misfire, in and of it self, ever. if it did, that means (only added air caused misfire, as would your right foot the same way)
It tells me the ECU is adding to much fuel, to that added new AIR, its ONLY job is that, and the MAP reads say, low vacuum too low it will cause the ECU to over inject, every time. (the map sensor on this car is what we call the KEY STONE device, (the heart of the system EFI)
The O2 sensor can trim it, but not if the map was super wrong. (02 is for only fine trimming the AFR, air fuel ratio, in fact the 02 corrects the normal map errors only at ilde and cruise and not wot.

(fast idle mode) opens the ISC and adds air to the induction for 1000rpm and then regulates RPM there, in closed tight loop (firmware loop for ISC servo actions)
so what causes rich? (defeat the EGR temporary, to get it out of the problem loop here)pull its vac hose and golf Tee, the end of hose.
02 stuck at 0v, for any reasons. (3 in the list, its bad, wires bad or exhaust cracks near by making it read 0v all time time)
map reads wrong, my map covers this 100% and how to test it and test the vacuum lines for trouble (clogs or splites)
injector leaks
fuel pressure at 55psi (not yours)
injector wiring hacks.
Bad ecu,
id be all over the map output voltages, key on, idle and gunned. per my map page.
http://www.fixkick.com
Reply


Messages In This Thread
RE: 1989 sidekick misfire when cold or when under electrical load - by fixkick - 03-19-2018, 03:33 AM

Forum Jump:


Users browsing this thread: 2 Guest(s)